JANUARY

1. Evasion of Classical Complement Pathway Activation on Plasmodium falciparum-Infected Erythrocytes Opsonized by PfEMP1-Specific IgG

Mads Delbo Larsen  ^{1   2} , Maria Del Pilar Quintana  ¹ , Sisse Bolm Ditlev  ¹ , Rafael Bayarri-Olmos  ² , Michael Fokuo Ofori  ³ , Lars Hviid  ^{1   4} , Peter Garred  ²

Front Immunol. 2019 Jan 7;9:3088. doi: 10.3389/fimmu.2018.03088. eCollection 2018.

Abstract

Members of the PfEMP1 protein family are expressed on the surface of P. falciparum-infected erythrocytes (IEs), where they contribute to the pathogenesis of malaria and are important targets of acquired immunity. Although the PfEMP1-specific antibody response is dominated by the opsonizing and complement-fixing subclasses IgG1 and IgG3, activation of the classical complement pathway by antibody-opsonized IEs does not appear to be a major immune effector mechanism. To study the molecular background for this, we used ELISA and flow cytometry to assess activation of the classical component pathway by recombinant and native PfEMP1 antigen opsonized by polyclonal and monoclonal PfEMP1-specific human IgG. Polyclonal IgG specific for VAR2CSA-type PfEMP1 purified from a pool of human immune plasma efficiently activated the classical complement pathway when bound to recombinant PfEMP1 in ELISA. In contrast, no activation of complement could be detected by flow cytometry when the same IgG preparation was used to opsonize IEs expressing the corresponding native PfEMP1 antigen. After engineering of a VAR2CSA-specific monoclonal antibody to facilitate its on-target hexamerization, complement activation was detectable in an ELISA optimized for uniform orientation of the immobilized antigen. In contrast, the antibody remained unable to activate complement when bound to native VAR2CSA on IEs. Our data suggest that the display of PfEMP1 proteins on IEs is optimized to prevent activation of the classical complement pathway, and thus represents a hitherto unappreciated parasite strategy to evade acquired immunity to malaria.

Keywords: PfEMP1; antibodies; complement; evasion; knobs; malaria.

2. Antileishmanial and Cytotoxic Activities of a New Limonoid and a New Phenyl Alkene From the Stem Bark of Trichilia Gilgiana (Meliaceae)

Theodora K Kowa  ^{1   2   3} , Lauve R Y Tchokouaha  ^{4   5} , Ewa Cieckiewicz  ² , Trudy Janice Philips  ⁶ , Eunice Dotse  ⁶ , Hippolyte K Wabo  ³ , Alembert T Tchinda  ¹ , Pierre Tane  ³ , Michel Frédérich  ²

Nat Prod Res. 2019 Jan 19:1-7. doi: 10.1080/14786419.2018.1553879. [Epub ahead of print]

Abstract

One new limonoid, trigilgianin (1), one new phenyl alkene, epoxy gilgialkene (2), together with five known compounds: scopoletin (3), sitosteryl-6'-O-undecanoate-β-D-glucoside (4), sitosteryl-O-β-D-glucopyranoside (5), cinchonain A (6) and cinchonain B (7) were isolated from the stem bark of Trichilia gilgiana Harms. (Meliaceae). All compounds were isolated for the first time from this species. The structures were elucidated on the basis of spectral studies and by comparison of these data with those from the literature. Compounds 1, 2, 3, 6 and 7 were tested for in vitro antileishmanial activity against visceral leishmaniasis parasite Leishmania donovani and cytotoxicity against macrophage RAW 264.7 cell line. Compounds 1 and 3 showed the highest antileishmanial activity (IC₅₀ values of 6.044 and 6.804 µg/mL, respectively) with low cytotoxicity (CC₅₀ values of >200 and 47.47 µg/mL, respectively), while compound 2 was moderately active on L. donovani promastigotes (IC₅₀ 56.81 µg/mL).

Keywords: Meliaceae; antileishmanial activity; cytotoxicity; limonoid; phenyl alkene.

3. Generational Conservation of Composition and Diversity of Field-Acquired Midgut Microbiota in Anopheles Gambiae (Sensu Lato) During Colonization in the Laboratory

Jewelna Akorli  ^{1   2} , Philomena Asor Namaali  ³ , Godwin Williams Ametsi  ⁴ , Richardson Kwesi Egyirifa  ³ , Nana Adjoa Praba Pels  ³

Parasit Vectors. 2019 Jan 11;12(1):27. doi: 10.1186/s13071-019-3287-0.

 

Abstract

Background: The gut microbiota is known to play a role in a mosquito vector's life history, a subject of increasing research. Laboratory experiments are essential for such studies and require laboratory colonies. In this study, the conservation of field-obtained midgut microbiota was evaluated in laboratory-reared Anopheles gambiae (s.l.) mosquitoes continuously hatched in water from field breeding habitats.

Methods: Pupae and late instars were obtained from the field and reared, and the emerged adults were blood-fed. The eggs obtained from them were hatched in either water from the field or in dechlorinated tap water. The mosquito colonies were maintained for 10 generations. Midguts of female adults from unfed F₀ (emerging from field-caught pupae and larvae), F₅ and F₁₀ were dissected out and genomic DNA was extracted for 16S metagenomic sequencing. The sequences were compared to investigate the diversity and bacterial compositional differences using ANCOM and correlation clustering methods.

Results: Less than 10% of the bacterial families identified had differential relative abundances between generational groups and accounted for 46% of the variation observed. Although diversity reduced in F₁₀ mosquitoes during laboratory colonization (Shannon-Weaver; P-value < 0.05), 50% of bacterial genera were conserved in those bred continuously in field-water compared to 38% in those bred in dechlorinated tap water.

Conclusions: To our knowledge, this study is the first report on the assessment of gut bacterial community of mosquitoes during laboratory colonization and recommends the use of water from the natural breeding habitats if they are intended for microbiota research.

Keywords: Anopheles gambiae (sensu lato); Breeding habitat; Field water; Laboratory colonization; Midgut microbiota.

 

4. In Vitro Assessment of Antiplasmodial Activity and Cytotoxicity of Polyalthia longifolia Leaf Extracts on Plasmodium falciparum Strain NF54

Bethel Kwansa-Bentum  ¹ , Kojo Agyeman  ² , Jeffrey Larbi-Akor  ¹ , Claudia Anyigba  ² , Regina Appiah-Opong  ^{2   3   4}

Malar Res Treat. 2019 Jan 21;2019:6976298. doi: 10.1155/2019/6976298. eCollection 2019.

PMID: 30805129

Abstract

Background: Malaria is one of the most important life-threatening infectious diseases in the tropics. In spite of the effectiveness of artemisinin-based combination therapy, reports on reduced sensitivity of the parasite to artemisinin in Cambodia and Thailand warrants screening for new potential antimalarial drugs for future use. Ghanaian herbalists claim that Polyalthia longifolia has antimalarial activity. Therefore, antiplasmodial activity, cytotoxic effects, and antioxidant and phytochemical properties of P. longifolia leaf extract were investigated in this study.

Methodology/principal findings: Aqueous, 70% hydroethanolic and ethyl acetate leaf extracts were prepared using standard procedures. Antiplasmodial activity was assessed in vitro by using chloroquine-sensitive malaria parasite strain NF54. The SYBR® Green and tetrazolium-based calorimetric assays were used to measure parasite growth inhibition and cytotoxicity, respectively, after extract treatment. Total antioxidant activity was evaluated using a free radical scavenging assay. Results obtained showed that extracts protected red blood cells against Plasmodium falciparum mediated damage. Fifty percent inhibitory concentration (IC₅₀) values were 24.0±1.08 μg/ml, 22.5±0.12 μg/ml, and 9.5±0.69 μg/ml for aqueous, hydroethanolic, and ethyl acetate extracts, respectively. Flavonoids, tannins, and saponins were present in the hydroethanolic extract, whereas only the latter was observed in the aqueous extract. Aqueous and hydroethanolic extracts showed stronger antioxidant activities compared to the ethyl acetate extract.

Conclusions/significance: The extracts of P. longifolia have antiplasmodial properties and low toxicities to human red blood cells. The extracts could be developed as useful alternatives to antimalarial drugs. These results support claims of the herbalists that decoctions of P. longifolia are useful antimalarial agents.

 

FEBRUARY

5. Strengthening Laboratory Surveillance of Viral Pathogens: Experiences and Lessons Learned Building Next-Generation Sequencing Capacity in Ghana

Rachel L Marine  ¹ , Nana Afia Asante Ntim  ² , Christina J Castro  ³ , Keren O Attiku  ² , Deborah Pratt  ² , Ewurabena Duker  ² , Esinam Agbosu  ² , Terry Fei Fan Ng  ⁴ , Wangeci Gatei  ⁵ , Evangeline Obodai  ² , John Kofi Odoom  ² , Chastity L Walker  ⁶ , Paul A Rota  ⁴ , M Steven Oberste  ⁴ , William Kwabena Ampofo  ² , S Arunmozhi Balajee  ⁴

 

Int J Infect Dis. 2019 Apr;81:231-234. doi: 10.1016/j.ijid.2019.02.008. Epub 2019 Feb 15.

 

Abstract

Objective: To demonstrate the feasibility of applying next-generation sequencing (NGS) in medium-resource reference laboratories in Africa to enhance global disease surveillance.

Methods: A training program was developed to support implementation of NGS at Noguchi Memorial Institute for Medical Research (NMIMR), University of Ghana. The program was divided into two training stages, first at the Centers for Disease Control and Prevention (CDC) in Atlanta, GA, followed by on-site training at NMIMR for a larger cohort of scientists.

Results: Self-assessment scores for topics covered during the NGS training program were higher post-training relative to pre-training. During the NGS Training II session at NMIMR, six enterovirus isolates from acute flaccid paralysis cases in Ghana were successfully sequenced by trainees, including two echovirus 6, two echovirus 11 and one echovirus 13. Another genome was an uncommon type (EV-B84), which has not been reported in Africa since its initial discovery from a Côte d'Ivoire specimen in 2003.

Conclusions: The success at NMIMR provides an example of how to approach transferring of NGS methods to international laboratories. There is great opportunity for collaboration between institutes that have genomics expertise to ensure effectiveness and long-term success of global NGS capacity building programs.

6. Genetic Markers of Benzimidazole Resistance Among Human Hookworms ( Necator americanus) in Kintampo North Municipality, Ghana

Ambrose R Orr  ¹ , Josephine E Quagraine  ^{2   1} , Peter Suwondo  ¹ , Santosh George  ¹ , Lisa M Harrison  ¹ , Fabio Pio Dornas  ¹ , Benjamin Evans  ³ , Adalgisa Caccone  ³ , Debbie Humphries  ⁴ , Michael D Wilson  ² , Michael Cappello  ¹

 

Am J Trop Med Hyg. 2019 Feb;100(2):351-356. doi: 10.4269/ajtmh.18-0727.

 

Abstract

Hookworm infection causes anemia, malnutrition, and growth delay, especially in children living in sub-Saharan Africa. The World Health Organization recommends periodic mass drug administration (MDA) of anthelminthics to school-age children (SAC) as a means of reducing morbidity. Recently, questions have been raised about the effectiveness of MDA as a global control strategy for hookworms and other soil-transmitted helminths (STHs). Genomic DNA was extracted from Necator americanus hookworm eggs isolated from SAC enrolled in a cross-sectional study of STH epidemiology and deworming response in Kintampo North Municipality, Ghana. A polymerase chain reaction (PCR) assay was then used to identify single-nucleotide polymorphisms (SNPs) associated with benzimidazole resistance within the N. americanus β-tubulin gene. Both F167Y and F200Y resistance-associated SNPs were detected in hookworm samples from infected study subjects. Furthermore, the ratios of resistant to wild-type SNP at these two loci were increased in posttreatment samples from subjects who were not cured by albendazole, suggesting that deworming drug exposure may enrich resistance-associated mutations. A previously unreported association between F200Y and a third resistance-associated SNP, E198A, was identified by sequencing of F200Y amplicons. These data confirm that markers of benzimidazole resistance are circulating among hookworms in central Ghana, with unknown potential to impact the effectiveness and sustainability of chemotherapeutic approaches to disease transmission and control.

7. Drug Resistance Mutations and Viral Load in Human Immunodeficiency Virus Type 2 and Dual HIV-1/HIV-2 Infected Patients in Ghana

Christopher Z Abana  ¹ , Kwamena W C Sagoe  ² , Evelyn Y Bonney  ¹ , Edward K Maina  ^{1   3} , Ishmael D Aziati  ^{1   4} , Esinam Agbosu  ¹ , Gifty Mawuli  ¹ , Linda M Styer  ⁵ , Koichi Ishikawa  ⁶ , James A M Brandful  ¹ , William K Ampofo  ¹

Medicine (Baltimore). 2019 Feb;98(6):e14313. doi: 10.1097/MD.0000000000014313

Abstract

Antiretroviral therapy (ART) and drug resistance studies worldwide have focused almost exclusively on human immunodeficiency virus type 1 (HIV-1). As a result, there is limited information on ART and drug resistance in HIV-2 patients. In Ghana, the HIV epidemic is characterized by the domination of HIV-1, with cocirculating HIV-2. We, therefore, sought to determine viral load and drug resistance mutations in HIV-2 patients to inform the clinical management of such individuals in Ghana.We used purposive sampling to collect blood from 16 consented patients, confirmed as HIV-2 or HIV-1/2 dual infections by serology. A 2-step real-time RT-PCR assay was used to determine plasma HIV-2 RNA viral loads. For drug resistance testing, nucleic acids were extracted from plasma and peripheral blood mononuclear cells. The reverse transcriptase and protease genes of HIV-2 were amplified, sequenced and analyzed for drug resistance mutations and HIV-2 group.HIV-2 viral load was detected in 9 of 16 patients. Six of these had quantifiable viral loads (range: 2.62-5.45 log IU/mL) while 3 had viral loads below the limit of quantification. Sequences were generated from 7 out of 16 samples. Five of these were classified as HIV-2 group B and 2 as HIV-2 group A. HIV-2 drug resistance mutations (M184V, K65R, Y115F) were identified in 1 patient.This study is the first to report HIV-2 viral load and drug resistance mutations in HIV-2 strains from Ghana. The results indicate the need for continuous monitoring of drug resistance among HIV-2- infected patients to improve their clinical management.

8. TB-diabetes Co-Morbidity in Ghana: The Importance of Mycobacterium Africanum Infection

Adwoa Asante-Poku  ^{1   2} , Prince Asare  ^{1   2} , Nyonuku Akosua Baddoo  ³ , Audrey Forson  ³ , Pius Klevor  ¹ , Isaac Darko Otchere  ¹ , Sammy Yaw Aboagye  ¹ , Stephen Osei-Wusu  ¹ , Emelia Konadu Danso  ¹ , Kwadwo Koram  ¹ , Sebastien Gagneux  ^{4   5} , Dorothy Yeboah-Manu  ¹

PLoS One. 2019 Feb 7;14(2):e0211822. doi: 10.1371/journal.pone.0211822. eCollection 2019

Abstract

Background: Diabetes Mellitus (DM) is a known risk factor for tuberculosis (TB) but little is known on TB-Diabetes Mellitus (TBDM) co-morbidity in Sub-Saharan Africa.

Methods: Consecutive TB cases registered at a tertiary facility in Ghana were recruited from September 2012 to April 2016 and screened for DM using random blood glucose and glycated hemoglobin (HbA1c) level. TB patients were tested for other clinical parameters including HIV co-infection and TB lesion location. Mycobacterial isolates obtained from collected sputum samples were characterized by standard methods. Associations between TBDM patients' epidemiological as well as microbiological variables were assessed.

Results: The prevalence of DM at time of diagnosis among 2990 enrolled TB cases was 9.4% (282/2990). TBDM cases were significantly associated with weight loss, poor appetite, night sweat and fatigue (p<0.001) and were more likely (p<0.001) to have lower lung cavitation 85.8% (242/282) compared to TB Non-Diabetic (TBNDM) patients 3.3% (90/2708). We observed 22.3% (63/282) treatment failures among TBDM patients compared to 3.8% (102/2708) among TBNDM patients (p<0.001). We found no significant difference in the TBDM burden attributed by M. tuberculosis sensu stricto (Mtbss) and Mycobacterium africanum (Maf) and (Mtbss; 176/1836, 9.6% and Maf; 53/468, 11.3%, p = 0.2612). We found that diabetic individuals were suggestively likely to present with TB caused by M. africanum Lineage 6 as opposed to Mtbss (odds ratio (OR) = 1.52; 95% confidence interval (CI): 0.92-2.42, p = 0.072).

Conclusion: Our findings confirms the importance of screening for diabetes during TB diagnosis and highlights the association between genetic diversity and diabetes. in Ghana.

9. Potential Factors Influencing Lymphatic Filariasis Transmission in "Hotspot" and "Control" Areas in Ghana: The Importance of Vectors

Sellase Pi-Bansa  ^{1   2   3} , Joseph Harold Nyarko Osei  ^{4   5} , Kwadwo Kyeremeh Frempong  ^{4   5} , Elizabeth Elhassan  ⁶ , Osei Kweku Akuoko  ^{4   7} , David Agyemang  ⁶ , Collins Ahorlu  ⁴ , Maxwell Alexander Appawu  ⁴ , Benjamin Guibehi Koudou  ^{8   9} , Michael David Wilson  ⁴ , Dziedzom Komi de Souza  ⁴ , Samuel Kweku Dadzie  ⁴ , Jürg Utzinger  ^{10   11} , Daniel Adjei Boakye  ⁴

 

Infect Dis Poverty. 2019 Feb 5;8(1):9. doi: 10.1186/s40249-019-0520-1.

 

Abstract

Background: Mass drug administration (MDA) programmes for the control of lymphatic filariasis in Ghana, have been ongoing in some endemic districts for 16 years. The current study aimed to assess factors that govern the success of MDA programmes for breaking transmission of lymphatic filariasis in Ghana.

Methods: The study was undertaken in two "hotspot" districts (Ahanta West and Kassena Nankana West) and two control districts (Mpohor and Bongo) in Ghana. Mosquitoes were collected and identified using morphological and molecular tools. A proportion of the cibarial armatures of each species was examined. Dissections were performed on Anopheles gambiae for filarial worm detection. A questionnaire was administered to obtain information on MDA compliance and vector control activities. Data were compared between districts to determine factors that might explain persistent transmission of lymphatic filariasis.

Results: High numbers of mosquitoes were sampled in Ahanta West district compared to Mpohor district (F = 16.09, P = 0.002). There was no significant difference between the numbers of mosquitoes collected in Kassena Nankana West and Bongo districts (F = 2.16, P = 0.185). Mansonia species were predominant in Ahanta West district. An. coluzzii mosquitoes were prevalent in all districts. An. melas with infected and infective filarial worms was found only in Ahanta West district. No differences were found in cibarial teeth numbers and shape for mosquito species in the surveyed districts. Reported MDA coverage was high in all districts. The average use of bednet and indoor residual spraying was 82.4 and 66.2%, respectively. There was high compliance in the five preceding MDA rounds in Ahanta West and Kassena Nankana West districts, both considered hotspots of lymphatic filariasis transmission.

Conclusions: The study on persistent transmission of lymphatic filariasis in the two areas in Ghana present information that shows the importance of local understanding of factors affecting control and elimination of lymphatic filariasis. Unlike Kassena Nankana West district where transmission dynamics could be explained by initial infection prevalence and low vector densities, ongoing lymphatic filariasis transmission in Ahanta West district might be explained by high biting rates of An. gambiae and initial infection prevalence, coupled with high densities of An. melas and Mansonia vector species that have low or no teeth and exhibiting limitation.

10. Rotavirus Vaccine Take in Infants Is Associated With Secretor Status

George E Armah  ¹ , Margaret M Cortese  ² , Francis E Dennis  ¹ , Ying Yu  ³ , Ardythe L Morrow  ³ , Monica M McNeal  ⁴ , Kristen D C Lewis  ⁵ , Denis A Awuni  ⁶ , Joseph Armachie  ¹ , Umesh D Parashar  ²

PMID: 30357332 DOI: 10.1093/infdis/jiy573  2019 Feb 15

 

Abstract

Rotaviruses bind to enterocytes in a genotype-specific manner via histo-blood group antigens (HBGAs), which are also detectable in saliva. We evaluated antirotavirus immunoglobulin A seroconversion ('vaccine take") among 166 Ghanaian infants after 2-3 doses of G1P[8] rotavirus vaccine during a vaccine trial, by HBGA status from saliva collected at age 4.1 years. Only secretor status was associated with seroconversion: 41% seroconversion for secretors vs 13% for nonsecretors; relative risk, 3.2 (95% confidence interval, 1.2-8.1; P = .016). Neither Lewis antigen nor salivary antigen blood type was associated with seroconversion. Likelihood of "take" for any particular rotavirus vaccine may differ across populations based on HBGAs.

11. Challenges Associated With the Treatment of Buruli Ulcer

Sammy Yaw Aboagye  ¹ , Grace Kpeli  ² , Joseph Tuffour  ³ , Dorothy Yeboah-Manu  ¹

PMID: 30168876  DOI: 10.1002/JLB.MR0318-128  Feb 2019

 

Abstract

Buruli ulcer (BU), caused by Mycobacterium ulcerans (MU), is the third most important mycobacterial diseases after tuberculosis and leprosy in immunocompetent individuals. Although the mode of transmission remains an enigma, disease incidence has been strongly linked to disturbed environment and wetlands. The blunt of the diseases is recorded in West African countries along the Gulf of Guinea, and children 15 years and below account for about 48% of all cases globally. Prior to 2004, wide surgical excisions and debridement of infected necrotic tissues followed by skin grafting was the accepted definitive treatment of BU. However, introduction of antibiotic therapy, daily oral rifampicin (10 mg/kg) plus intramuscular injection of streptomycin (15 mg/kg), for 8 weeks by the WHO in 2004 has reduced surgery as an adjunct for correction of deformities and improved wound healing. An all-oral regimen is currently on clinical trial to replace the injectable. It is thought that a protective cloud of the cytotoxic toxin mycolactone kills infiltrating leucocytes leading to local immunosuppression and down-regulation of the systemic immune system. Our studies of lesions from BU patients treated with SR have demonstrated treatment-associated initiation of vigorous immune responses and the development of ectopic lymphoid tissue in the BU lesions. Despite these interventions, there are still challenges that bedevil the management of BU including paradoxical reactions, evolution of lesions after therapy, prolong viability of MU in BU lesions, and development of secondary bacterial infection. In this paper, we will mainly focus on the critical and pertinent challenges that undermine BU treatment toward effective control of BU.

 

MARCH

12. Improving Treatment Outcomes for MDR-TB - Novel Host-Directed Therapies and Personalised Medicine of the Future

Martin Rao  ¹ , Giuseppe Ippolito  ² , Sayoki Mfinanga  ³ , Francine Ntoumi  ⁴ , Dorothy Yeboah-Manu  ⁵ , Cris Vilaplana  ⁶ , Alimuddin Zumla  ⁷ , Markus Maeurer  ⁸

Int J Infect Dis. 2019 Mar;80S:S62-S67. doi: 10.1016/j.ijid.2019.01.039. Epub 2019 Jan 24.

Abstract

Multidrug-resistant TB (MDR-TB) is a major threat to global health security. In 2017, only 50% of patients with MDR-TB who received WHO-recommended treatment were cured. Most MDR-TB patients who recover continue to suffer from functional disability due to long-term lung damage. Whilst new MDR-TB treatment regimens are becoming available, conventional drug therapies need to be complemented with host-directed therapies (HDTs) to reduce tissue damage and improve functional treatment outcomes. This viewpoint highlights recent data on biomarkers, immune cells, circulating effector molecules and genetics which could be utilised for developing personalised HDTs. Novel technologies currently used for cancer therapy which could facilitate in-depth understanding of host genetics and the microbiome in patients with MDR-TB are discussed. Against this background, personalised cell-based HDTs for adjunct MDR-TB treatment to improve clinical outcomes are proposed as a possibility for complementing standard therapy and other HDT agents. Insights into the molecular biology of the mechanisms of action of cellular HDTs may also aid to devise non-cell-based therapies targeting defined inflammatory pathway(s) in Mtb-driven immunopathology.

Keywords: Biomarkers; Clinical studies; Host-directed therapies; Immunotherapy; Multidrug-resistant tuberculosis; Personalised medicine.

Copyright © 2019. Published by Elsevier Ltd.

13. Soluble FcɛRI: A biomarker for IgE-mediated diseases.

Moñino-Romero S, Lexmond WS, Singer J, Bannert C, Amoah AS, Yazdanbakhsh M, Boakye DA, Jensen-Jarolim E, Fiebiger E, Szépfalusi Z.

Allergy. 2019 Jul;74(7):1381-1384. doi: 10.1111/all.13734. Epub 2019 Mar 11.

No abstract available.

14.  The Temporal Dynamics and Infectiousness of Subpatent Plasmodium Falciparum Infections in Relation to Parasite Density

Hannah C Slater  ¹ , Amanda Ross  ^{2   3} , Ingrid Felger  ^{3   4} , Natalie E Hofmann  ^{3   4} , Leanne Robinson  ^{5   6   7   8} , Jackie Cook  ⁹ , Bronner P Gonçalves  ¹⁰ , Anders Björkman  ¹¹ , Andre Lin Ouedraogo  ^{12   13} , Ulrika Morris  ¹¹ , Mwinyi Msellem  ¹⁴ , Cristian Koepfli  ^{15   16} , Ivo Mueller  ^{6   17   7} , Fitsum Tadesse  ^{18   19   20} , Endalamaw Gadisa  ¹⁹ , Smita Das  ²¹ , Gonzalo Domingo  ²¹ , Melissa Kapulu  ^{22   23} , Janet Midega  ^{22   23} , Seth Owusu-Agyei  ²⁴ , Cécile Nabet  ²⁵ , Renaud Piarroux  ²⁵ , Ogobara Doumbo  ²⁶ , Safiatou Niare Doumbo  ²⁶ , Kwadwo Koram  ²⁷ , Naomi Lucchi  ²⁸ , Venkatachalam Udhayakumar  ²⁸ , Jacklin Mosha  ²⁹ , Alfred Tiono  ³⁰ , Daniel Chandramohan  ³¹ , Roly Gosling  ³² , Felista Mwingira  ³³ , Robert Sauerwein  ¹⁸ , Richard Paul  ³⁴ , Eleanor M Riley  ^{10   35} , Nicholas J White  ^{36   37} , Francois Nosten  ^{36   38} , Mallika Imwong  ^{37   39} , Teun Bousema  ^{10   18} , Chris Drakeley  ¹⁰ , Lucy C Okell  ⁴⁰

Nat Commun. 2019 Mar 29;10(1):1433. doi: 10.1038/s41467-019-09441-1. Erratum in: Nat Commun. 2019 Jun 11;10(1):2644.

 

• Author Correction: The Temporal Dynamics and Infectiousness of Subpatent Plasmodium Falciparum Infections in Relation to Parasite Density

HC Slater et al. Nat Commun 10 (1), 2644. 2019. PMID 31186429.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Abstract

Malaria infections occurring below the limit of detection of standard diagnostics are common in all endemic settings. However, key questions remain surrounding their contribution to sustaining transmission and whether they need to be detected and targeted to achieve malaria elimination. In this study we analyse a range of malaria datasets to quantify the density, detectability, course of infection and infectiousness of subpatent infections. Asymptomatically infected individuals have lower parasite densities on average in low transmission settings compared to individuals in higher transmission settings. In cohort studies, subpatent infections are found to be predictive of future periods of patent infection and in membrane feeding studies, individuals infected with subpatent asexual parasite densities are found to be approximately a third as infectious to mosquitoes as individuals with patent (asexual parasite) infection. These results indicate that subpatent infections contribute to the infectious reservoir, may be long lasting, and require more sensitive diagnostics to detect them in lower transmission settings.

15. Reference Set of Mycobacterium Tuberculosis Clinical Strains: A Tool for Research and Product Development

Sònia Borrell  ^{1   2} , Andrej Trauner  ^{1   2} , Daniela Brites  ^{1   2} , Leen Rigouts  ^{3   4} , Chloe Loiseau  ^{1   2} , Mireia Coscolla  ^{1   2} , Stefan Niemann  ⁵ , Bouke De Jong  ³ , Dorothy Yeboah-Manu  ⁶ , Midori Kato-Maeda  ⁷ , Julia Feldmann  ^{1   2} , Miriam Reinhard  ^{1   2} , Christian Beisel  ⁸ , Sebastien Gagneux  ^{1   2}

PLoS One. 2019 Mar 25;14(3):e0214088. doi: 10.1371/journal.pone.0214088. eCollection 2019

 

Abstract

The Mycobacterium tuberculosis complex (MTBC) causes tuberculosis (TB) in humans and various other mammals. The human-adapted members of the MTBC comprise seven phylogenetic lineages that differ in their geographical distribution. There is growing evidence that this phylogeographic diversity modulates the outcome of TB infection and disease. For decades, TB research and development has focused on the two canonical MTBC laboratory strains H37Rv and Erdman, both of which belong to Lineage 4. Relying on only a few laboratory-adapted strains can be misleading as study results might not be directly transferrable to clinical settings where patients are infected with a diverse array of strains, including drug-resistant variants. Here, we argue for the need to expand TB research and development by incorporating the phylogenetic diversity of the MTBC. To facilitate such work, we have assembled a group of 20 genetically well-characterized clinical strains representing the seven known human-adapted MTBC lineages. With the "MTBC clinical strains reference set" we aim to provide a standardized resource for the TB community. We hope it will enable more direct comparisons between studies that explore the physiology of MTBC beyond the laboratory strains used thus far. We anticipate that detailed phenotypic analyses of this reference strain set will increase our understanding of TB biology and assist in the development of new control tools that are broadly effective.

16. Oral Activity of the Antimalarial Endoperoxide 6-(1,2,6,7-tetraoxaspiro[7.11]nonadec-4-yl)hexan-1-ol (N-251) Against Leishmania Donovani Complex

Kofi Dadzie Kwofie  ^{1   2} , Kai Sato  ² , Chizu Sanjoba  ² , Akina Hino  ¹ , Rieko Shimogawara  ¹ , Michael Amoa-Bosompem  ¹ , Irene Ayi  ³ , Daniel A Boakye  ³ , Abraham K Anang  ³ , Kyung-Soo Chang  ⁴ , Mitsuko Ohashi  ¹ , Hye-Sook Kim  ⁵ , Nobuo Ohta  ¹ , Yoshitsugu Matsumoto  ² , Shiroh Iwanaga  ¹

PLoS Negl Trop Dis. 2019 Mar 25;13(3):e0007235. doi: 10.1371/journal.pntd.0007235. eCollection 2019 Mar.

 

Abstract

Visceral leishmaniasis (VL) is a major problem worldwide and causes significant morbidity and mortality. Existing drugs against VL have limitations, including their invasive means of administration long duration of treatment regimens. There are also concerns regarding increasing treatment relapses as well as the identification of resistant clinical strains with the use of miltefosine, the sole oral drug for VL. There is, therefore, an urgent need for new alternative oral drugs for VL. In the present study, we show the leishmanicidal effect of a novel, oral antimalarial endoperoxide N-251. In our In vitro studies, N-251 selectively and specifically killed Leishmania donovani D10 amastigotes with no accompanying toxicity toward the host cells. In addition, N-251 exhibited comparable activities against promastigotes of L. donovani D10, as well as other L. donovani complex parasites, suggesting a wide spectrum of activity. Furthermore, even after a progressive infection was established in mice, N-251 significantly eliminated amastigotes when administered orally. Finally, N-251 suppressed granuloma formation in mice liver through parasite death. These findings indicate the therapeutic effect of N-251 as an oral drug, hence suggest N-251 to be a promising lead compound for the development of a new oral chemotherapy against VL.

17. Assessing the Presence of Wuchereria bancrofti Infections in Vectors Using Xenomonitoring in Lymphatic Filariasis Endemic Districts in Ghana

Sellase Pi-Bansa  ^{1   2   3} , Joseph H N Osei  ^{4   5} , Worlasi D Kartey-Attipoe  ⁶ , Elizabeth Elhassan  ⁷ , David Agyemang  ⁸ , Sampson Otoo  ⁹ , Samuel K Dadzie  ¹⁰ , Maxwell A Appawu  ¹¹ , Michael D Wilson  ¹² , Benjamin G Koudou  ^{13   14} , Dziedzom K de Souza  ¹⁵ , Jürg Utzinger  ^{16   17} , Daniel A Boakye  ¹⁸

Trop Med Infect Dis. 2019 Mar 17;4(1). pii: E49. doi: 10.3390/tropicalmed4010049

Abstract

Mass drug administration (MDA) is the current mainstay to interrupt the transmission of lymphatic filariasis. To monitor whether MDA is effective and transmission of lymphatic filariasis indeed has been interrupted, rigorous surveillance is required. Assessment of transmission by programme managers is usually done via serology. New research suggests that xenomonitoring holds promise for determining the success of lymphatic filariasis interventions. The objective of this study was to assess Wuchereria bancrofti infection in mosquitoes as a post-MDA surveillance tool using xenomonitoring. The study was carried out in four districts of Ghana; Ahanta West, Mpohor, Kassena Nankana West and Bongo. A suite of mosquito sampling methods was employed, including human landing collections, pyrethrum spray catches and window exit traps. Infection of W. bancrofti in mosquitoes was determined using dissection, conventional and real-time polymerase chain reaction and loop mediated isothermal amplification assays. Aedes, Anopheles coustani, An. gambiae, An. pharoensis, Culex and Mansonia mosquitoes were sampled in each of the four study districts. The dissected mosquitoes were positive for filarial infection using molecular assays. Dissected An. melas mosquitoes from Ahanta West district were the only species found positive for filarial parasites. We conclude that whilst samples extracted with Trizol reagent did not show any positives, molecular methods should still be considered for monitoring and surveillance of lymphatic filariasis transmission.

18. Characterizing Local-Scale Heterogeneity of Malaria Risk: A Case Study in Bunkpurugu-Yunyoo District in Northern Ghana

Punam Amratia  ^{1   2} , Paul Psychas  ³ , Benjamin Abuaku  ⁴ , Collins Ahorlu  ⁴ , Justin Millar  ^{5   3} , Samuel Oppong  ⁶ , Kwadwo Koram  ⁴ , Denis Valle  ^{5   3}

Malar J. 2019 Mar 15;18(1):81. doi: 10.1186/s12936-019-2703-4.

 

Abstract

Background: Bayesian methods have been used to generate country-level and global maps of malaria prevalence. With increasing availability of detailed malaria surveillance data, these methodologies can also be used to identify fine-scale heterogeneity of malaria parasitaemia for operational prevention and control of malaria.

Methods: In this article, a Bayesian geostatistical model was applied to six malaria parasitaemia surveys conducted during rainy and dry seasons between November 2010 and 2013 to characterize the micro-scale spatial heterogeneity of malaria risk in northern Ghana.

Results: The geostatistical model showed substantial spatial heterogeneity, with malaria parasite prevalence varying between 19 and 90%, and revealing a northeast to southwest gradient of predicted risk. The spatial distribution of prevalence was heavily influenced by two modest urban centres, with a substantially lower prevalence in urban centres compared to rural areas. Although strong seasonal variations were observed, spatial malaria prevalence patterns did not change substantially from year to year. Furthermore, independent surveillance data suggested that the model had a relatively good predictive performance when extrapolated to a neighbouring district.

Conclusions: This high variability in malaria prevalence is striking, given that this small area (approximately 30 km × 40 km) was purportedly homogeneous based on country-level spatial analysis, suggesting that fine-scale parasitaemia data might be critical to guide district-level programmatic efforts to prevent and control malaria. Extrapolations results suggest that fine-scale parasitaemia data can be useful for spatial predictions in neighbouring unsampled districts and does not have to be collected every year to aid district-level operations, helping to alleviate concerns regarding the cost of fine-scale data collection.

19. Association Between Alpha-Thalassaemia Trait, Plasmodium Falciparum Asexual Parasites and Gametocyte Carriage in a Malaria Endemic Area in Southern Ghana

Helena Lamptey  ¹ , Michael Fokuo Ofori  ² , Bright Adu  ² , Kwadwo Asamoah Kusi  ² , Emmanuel Kakra Dickson  ² , Isabella Quakyi  ³ , Michael Alifrangis  ^{4   5}

BMC Res Notes. 2019 Mar 13;12(1):134. doi: 10.1186/s13104-019-4181-8.

 

Abstract

Objective: The alpha-thalassaemia trait has been associated with protection against severe malaria but its role in Plasmodium falciparum asexual parasite and gametocyte carriage remains unclear. This study examined association between prevalence of α-thalassaemia and P. falciparum asexual stage parasitaemia and gametocytaemia in children, pregnant women and adults, which was part of a bigger study that investigated some key factors that influence gametocyte carriage.

Results: Overall prevalence of heterozygous α-thalassaemia trait among all the groups was 39.0%, while 8.2% were homozygous alpha thalassaemia. Asexual parasite prevalence was significantly higher in children (P = 0.008) compared to adults and pregnant women. Of the asexual P. falciparum positive individuals, gametocyte prevalence was 38.5% (15/39) in children, 29.7% (11/37) in pregnant women and 17.4% (4/23) in adults. Heterozygous α-thalassaemic children were less likely to harbour asexual parasites, compared with normal and those deficient (OR = 0.52; 95% CI 0.28-0.97; P = 0.037) under the dominant model. These heterozygous children were also associated with reduced risk of parasitaemia compared to heterozygous adults and pregnant women. Children with heterozygous α-thalassaemia trait had reduced risk of asexual parasite carriage. There was however, no association between α-thalassaemia trait and risk of gametocyte carriage.

20. Prevalence and Correlates of Stroke Among Older Adults in Ghana: Evidence From the Study on Global AGEing and Adult Health (SAGE)

Olutobi Adekunle Sanuade  ¹ , Francis Nii-Amoo Dodoo  ² , Kwadwo Koram  ³ , Ama de-Graft Aikins  ²

PLoS One. 2019 Mar 13;14(3):e0212623. doi: 10.1371/journal.pone.0212623. eCollection 2019.

 

Abstract

This study examines the prevalence and correlates of stroke among older adults in Ghana. This cross-sectional study retrieved data from Wave 1 of the World Health Organization (WHO) Survey on Global Ageing and Adult Health (SAGE) conducted between 2007 and 2008. The sample, comprising 4,279 respondents aged 50 years and above, was analysed using descriptive statistics, cross tabulations and Chi-Square tests, and a multivariable binary logistic regression. Respondents ranged in age from 50 to 114 years, with a median age of 62 years. Stroke prevalence was 2.6%, with the correlates being marital status, level of education, employment status, and living with hypertension or diabetes. The results showed that being separated/divorced, having primary and secondary education, being unemployed and living with hypertension and diabetes, significantly increased the odds of stroke prevalence in this population. The results suggest that interventions to reduce stroke prevalence and impact must be developed alongside interventions for hypertension, diabetes and sociodemographic/economic factors such as marital status, level of education, and employment status.

 

21. Molecular Epidemiology and Whole Genome Sequencing Analysis of Clinical Mycobacterium Bovis From Ghana

Isaac Darko Otchere  ¹ , Andries J van Tonder  ² , Adwoa Asante-Poku  ¹ , Leonor Sánchez-Busó  ² , Mireia Coscollá  ³ , Stephen Osei-Wusu  ¹ , Prince Asare  ¹ , Samuel Yaw Aboagye  ¹ , Samuel Acquah Ekuban  ⁴ , Abdallah Iddrisu Yahayah  ⁴ , Audrey Forson  ⁵ , Akosua Baddoo  ⁵ , Clement Laryea  ⁶ , Julian Parkhill  ² , Simon R Harris  ² , Sebastien Gagneux  ^{7   8} , Dorothy Yeboah-Manu  ¹

PLoS One. 2019 Mar 4;14(3):e0209395. doi: 10.1371/journal.pone.0209395. eCollection 2019.

 

Abstract

Background: Bovine tuberculosis (bTB) caused by Mycobacterium bovis is a re-emerging problem in both livestock and humans. The association of some M. bovis strains with hyper-virulence, MDR-TB and disseminated disease makes it imperative to understand the biology of the pathogen.

Methods: Mycobacterium bovis (15) among 1755 M. tuberculosis complex (MTBC) isolated between 2012 and 2014 were characterized and analyzed for associated patient demography and other risk factors. Five of the M. bovis isolates were whole-genome sequenced and comparatively analyzed against a global collection of published M. bovis genomes.

Results: Mycobacterium bovis was isolated from 3/560(0.5%) females and 12/1195(1.0%) males with pulmonary TB. The average age of M. bovis infected cases was 46.8 years (7-72years). TB patients from the Northern region of Ghana (1.9%;4/212) had a higher rate of infection with M. bovis (OR = 2.7,p = 0.0968) compared to those from the Greater Accra region (0.7%;11/1543). Among TB patients with available HIV status, the odds of isolating M. bovis from HIV patients (2/119) was 3.3 higher relative to non-HIV patients (4/774). Direct contact with livestock or their unpasteurized products was significantly associated with bTB (p<0.0001, OR = 124.4,95% CI = 30.1-508.3). Two (13.3%) of the M. bovis isolates were INH resistant due to the S315T mutation in katG whereas one (6.7%) was RIF resistant with Q432P and I1491S mutations in rpoB. M. bovis from Ghana resolved as mono-phyletic branch among mostly M. bovis from Africa irrespective of the host and were closest to the root of the global M. bovis phylogeny. M. bovis-specific amino acid mutations were detected among MTBC core genes such as mce1A, mmpL1, pks6, phoT, pstB, glgP and Rv2955c. Additional mutations P6T in chaA, G187E in mgtC, T35A in Rv1979c, S387A in narK1, L400F in fas and A563T in eccA1 were restricted to the 5 clinical M. bovis from Ghana.

22. Latent TB Infection (LTBI) - Mycobacterium Tuberculosis Pathogenesis and the Dynamics of the Granuloma Battleground

Martin Rao  ¹ , Giuseppe Ippolito  ² , Sayoki Mfinanga  ³ , Francine Ntoumi  ⁴ , Dorothy Yeboah-Manu  ⁵ , Cristina Vilaplana  ⁶ , Alimuddin Zumla  ⁷ , Markus Maeurer  ⁸

Int J Infect Dis. 2019 Mar;80S:S58-S61. doi: 10.1016/j.ijid.2019.02.035. Epub 2019 Feb 26.

 

Abstract

Latent tuberculosis infection (LTBI) is established in over 90% of persons infected with Mycobacterium tuberculosis (Mtb), from whom new active TB cases will arise. Understanding the spatio-temporal dynamics of host immune responses in LTBI granulomas is essential to designing effective post-exposure therapies that inhibit progression to TB. Information arising from cancer studies and other modalities - where local chronic inflammation leads to immunopathology - can help provide insights into the biological pathways at play in LTBI granulomas. Translational studies using patient material as well as LTBI+ donor-derived tissue samples are instrumental in understanding the various components of granuloma dynamics, immunological landscapes therein and how this could help to identify therapeutic targets. Deep sequencing technologies may aid to decipher the genetic changes in lung granuloma and blood samples from LTBI+ individuals associated with progression to active TB disease. This may lead to advancement of development of targeted Host-Directed Therapies (HDTs) and their evaluation as adjunct TB therapies for improving treatment outcomes for LTBI and pulmonary TB.

23. Molecular Docking and Dynamics Simulation Studies Predict Munc18b as a Target of Mycolactone: A Plausible Mechanism for Granule Exocytosis Impairment in Buruli Ulcer Pathogenesis

Samuel K Kwofie  ^{1   2   3} , Bismark Dankwa  ⁴ , Kweku S Enninful  ⁵ , Courage Adobor  ⁶ , Emmanuel Broni  ⁷ , Alfred Ntiamoah  ⁸ , Michael D Wilson  ⁹

Toxins (Basel). 2019 Mar 25;11(3). pii: E181. doi: 10.3390/toxins11030181.

 

 

Abstract

Ulcers due to infections with Mycobacterium ulcerans are characterized by complete lack of wound healing processes, painless, an underlying bed of host dead cells and undermined edges due to necrosis. Mycolactone, a macrolide produced by the mycobacterium, is believed to be the toxin responsible. Of interest and relevance is the knowledge that Buruli ulcer (BU) patients remember experiencing trauma previously at the site of the ulcers, suggesting an impairment of wound healing processes, the plausible effect due to the toxin. Wound healing processes involve activation of the blood platelets to release the contents of the dense granules mainly serotonin, calcium ions, and ADP/ATP by exocytosis into the bloodstream. The serotonin release results in attracting more platelets and mast cells to the wound site, with the mast cells also undergoing degranulation, releasing compounds into the bloodstream by exocytosis. Recent work has identified interference in the co-translational translocation of many secreted proteins via the endoplasmic reticulum and cell death involving Wiskott-Aldrich syndrome protein (WASP), Sec61, and angiotensin II receptors (AT2R). We hypothesized that mycolactone by being lipophilic, passively crosses cell membranes and binds to key proteins that are involved in exocytosis by platelets and mast cells, thus inhibiting the initiation of wound healing processes. Based on this, molecular docking studies were performed with mycolactone against key soluble n-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins and regulators, namely Vesicle-associated membrane protein (VAMP8), Synaptosomal-associated protein (SNAP23, syntaxin 11, Munc13-4 (its isoform Munc13-1 was used), and Munc18b; and also against known mycolactone targets (Sec61, AT2R, and WASP). Munc18b was shown to be a plausible mycolactone target after the molecular docking studies with binding affinity of -8.5 kcal/mol. Structural studies and molecular mechanics Poisson-Boltzmann surface area (MM-PBSA) binding energy calculations of the mycolactone and Munc18b complex was done with 100 ns molecular dynamics simulations using GROMACS. Mycolactone binds strongly to Munc18b with an average binding energy of -247.571 ± 37.471 kJ/mol, and its presence elicits changes in the structural conformation of the protein. Analysis of the binding interactions also shows that mycolactone interacts with Arg405, which is an important residue of Munc18b, whose mutation could result in impaired granule exocytosis. These findings consolidate the possibility that Munc18b could be a target of mycolactone. The implication of the interaction can be experimentally evaluated to further understand its role in granule exocytosis impairment in Buruli ulcer.

24. Differential Patterns of IgG Subclass Responses to Plasmodium falciparum Antigens in Relation to Malaria Protection and RTS,S Vaccination

Carlota Dobaño  ^{1   2} , Rebeca Santano  ¹ , Marta Vidal  ¹ , Alfons Jiménez  ^{1   3} , Chenjerai Jairoce  ² , Itziar Ubillos  ¹ , David Dosoo  ⁴ , Ruth Aguilar  ¹ , Nana Aba Williams  ¹ , Núria Díez-Padrisa  ¹ , Aintzane Ayestaran  ¹ , Clarissa Valim  ^{5   6} , Kwaku Poku Asante  ⁴ , Seth Owusu-Agyei  ^{4   7} , David Lanar  ⁸ , Virander Chauhan  ⁹ , Chetan Chitnis  ⁹ , Sheetij Dutta  ⁸ , Evelina Angov  ⁸ , Benoit Gamain  ¹⁰ , Ross L Coppel  ¹¹ , James G Beeson  ¹² , Linda Reiling  ¹² , Deepak Gaur  ^{9   13} , David Cavanagh  ¹⁴ , Ben Gyan  ^{4   15} , Augusto J Nhabomba  ² , Joseph J Campo  ^{1   2} , Gemma Moncunill  ^{1   2}

Front Immunol. 2019 Mar 15;10:439. doi: 10.3389/fimmu.2019.00439. eCollection 2019.

 

Abstract

Naturally acquired immunity (NAI) to Plasmodium falciparum malaria is mainly mediated by IgG antibodies but the subclasses, epitope targets and effector functions have not been unequivocally defined. Dissecting the type and specificity of antibody responses mediating NAI is a key step toward developing more effective vaccines to control the disease. We investigated the role of IgG subclasses to malaria antigens in protection against disease and the factors that affect their levels, including vaccination with RTS,S/AS01E. We analyzed plasma and serum samples at baseline and 1 month after primary vaccination with RTS,S or comparator in African children and infants participating in a phase 3 trial in two sites of different malaria transmission intensity: Kintampo in Ghana and Manhiça in Mozambique. We used quantitative suspension array technology (qSAT) to measure IgG_1-4 responses to 35 P. falciparum pre-erythrocytic and blood stage antigens. Our results show that the pattern of IgG response is predominantly IgG1 or IgG3, with lower levels of IgG2 and IgG4. Age, site and RTS,S vaccination significantly affected antibody subclass levels to different antigens and susceptibility to clinical malaria. Univariable and multivariable analysis showed associations with protection mainly for cytophilic IgG3 levels to selected antigens, followed by IgG1 levels and, unexpectedly, also with IgG4 levels, mainly to antigens that increased upon RTS,S vaccination such as MSP5 and MSP1 block 2, among others. In contrast, IgG2 was associated with malaria risk. Stratified analysis in RTS,S vaccinees pointed to novel associations of IgG4 responses with immunity mainly involving pre-erythrocytic antigens upon RTS,S vaccination. Multi-marker analysis revealed a significant contribution of IgG3 responses to malaria protection and IgG2 responses to malaria risk. We propose that the pattern of cytophilic and non-cytophilic IgG antibodies is antigen-dependent and more complex than initially thought, and that mechanisms of both types of subclasses could be involved in protection. Our data also suggests that RTS,S efficacy is significantly affected by NAI, and indicates that RTS,S vaccination significantly alters NAI.

 

APRIL

25. Ability of Vital and Fluorescent Staining in the Differentiation of Schistosoma haematobium Live and Dead Eggs

Peter O Forson  ¹ , Patience B Tetteh-Quarcoo  ² , John Ahenkorah  ³ , Robert Aryee  ^{4   5} , Esther N Okine  ⁶ , Emmanuel Afutu  ⁷ , Georgina I Djameh  ⁸ , Jeffrey Agyapong  ⁹ , Abraham K Anang  ¹⁰ , Patrick F Ayeh-Kumi  ¹¹

Med Sci (Basel). 2019 Apr 23;7(4). pii: E64. doi: 10.3390/medsci7040064

Abstract

This study reports (for the first time) the staining ability of vital (0.4% trypan blue and 1% neutral red) and fluorescent (Hoechst 33258) dyes to differentiate between live and dead Schistosoma haematobium (S. haematobium) eggs in human urine samples. Since S. haematobium egg is important in disease pathology, diagnosis, transmission, and drug development research, it is essential to be able to easily distinguish live eggs from dead ones. Staining is considered a way of enhancing the identification of live and dead eggs. Urine samples from school children were examined for the presence of S. haematobium eggs. Vital and fluorescent dyes were used to stain the samples that contained S. haematobium eggs, after which they were observed using light and fluorescent microscopes, respectively. The Hoechst 33258 provided a good staining outcome for differentiation between live and dead eggs, followed by 0.4% Trypan blue. Regarding the 1% neutral red stain, even though it provided some evidence of which egg was alive or dead, the distinction was not very clear; therefore, it could be useful when used in combination with other stains for egg viability determination. The benefits of this study will include assessing the effect of drugs on S. haematobium eggs in Schistosomiasis research.

26.  Rodent-borne Infections in Rural Ghanaian Farming Communities

Shirley C Nimo-Paintsil  ^{1   2} , Elisabeth Fichet-Calvet  ³ , Benny Borremans  ^{4   5} , Andrew G Letizia  ¹ , Emad Mohareb  ⁶ , Joseph H K Bonney  ² , Kwasi Obiri-Danso  ⁷ , William K Ampofo  ² , Randal J Schoepp  ⁸ , Karl C Kronmann  ^{1   9}

PLoS One. 2019 Apr 24;14(4):e0215224. doi: 10.1371/journal.pone.0215224. eCollection 2019. Erratum in: PLoS One. 2019 Jun 6;14(6):e0218271

Abstract

Rodents serve as reservoirs and/or vectors for several human infections of high morbidity and mortality in the tropics. Population growth and demographic shifts over the years have increased contact with these mammals, thereby increasing opportunities for disease transmission. In Africa, the burden of rodent-borne diseases is not well described. To investigate human seroprevalence of selected rodent-borne pathogens, sera from 657 healthy adults in ten rural communities in Ghana were analyzed. An in-house enzyme-linked immunosorbent assay (ELISA), for immunoglobulin G (IgG) antibodies to Lassa virus was positive in 34 (5%) of the human samples. Using commercial kits, antibodies to hantavirus serotypes, Puumala and Dobrava, and Leptospira bacteria were detected in 11%, 12% and 21% of the human samples, respectively. Forty percent of residents in rural farming communities in Ghana have measurable antibodies to at least one of the rodent-borne pathogens tested, including antibodies to viral hemorrhagic fever viruses. The high seroprevalence found in rural Ghana to rodent-borne pathogens associated with both sporadic cases and larger disease outbreaks will help define disease threats and inform public health policy to reduce disease burden in underserved populations and deter larger outbreaks.

27. Rapid High Throughput SYBR Green Assay for Identifying the Malaria Vectors Anopheles Arabiensis, Anopheles Coluzzii and Anopheles Gambiae s.s. Giles

Joseph Chabi  ¹ , Arjen Van't Hof  ² , Louis K N'dri  ¹ , Alex Datsomor  ¹ , Dora Okyere  ¹ , Harun Njoroge  ³ , Dimitra Pipini  ² , Melinda P Hadi  ^{1   4} , Dziedzom K de Souza  ¹ , Takashi Suzuki  ⁵ , Samuel K Dadzie  ¹ , Helen P Jamet  ⁶

PLoS One. 2019 Apr 19;14(4):e0215669. doi: 10.1371/journal.pone.0215669. eCollection 2019.

 

Abstract

The Anopheles gambiae sensu lato species complex consists of a number of cryptic species with different habitats and behaviours. These morphologically indistinct species are identified by chromosome banding. Several molecular diagnostic techniques for distinguishing between An. coluzzii and An. gambiae are still under improvement. Although, the current SINE method for identification between An. coluzzii and An. gambiae works reliably, this study describes a refinement of the SINE method to increase sensitivity for identification of An. coluzzii, An. gambiae and An. arabiensis based on amplicon dissociation curve characteristics. Field-collected samples, laboratory-reared colonies and crossed specimens of the two species were used for the design of the protocol. An. gambiae, An. coluzzii, and hybrids of the two species were sampled from Ghana and An. arabiensis from Kenya. Samples were first characterised using conventional SINE PCR method, and further assayed using SYBR green, an intercalating fluorescent dye. The three species and hybrids were clearly differentiated using the melting temperature of the dissociation curves, with derivative peaks at 72°C for An. arabiensis, 75°C for An. gambiae and 86°C for An. coluzzii. The hybrids (An. gambiae / An. coluzzii) showed both peaks. This work is the first to describe a SYBR green real time PCR method for the characterization of An. arabiensis, An. gambiae and An. coluzzii and was purposely designed for basic melt-curve analysis (rather than high-resolution melt-curve) to allow it to be used on a wide range of real-time PCR machines.

28.  Comprehensive Analysis of Fc-mediated IgM Binding to the Plasmodium Falciparum Erythrocyte Membrane Protein 1 Family in Three Parasite Clones

Maria Del Pilar Quintana  ¹ , Gertrude Ecklu-Mensah  ^{1   2} , Sergey O Tcherniuk  ³ , Sisse Bolm Ditlev  ¹ , Andrew V Oleinikov  ³ , Lars Hviid  ^{4   5} , Mary Lopez-Perez  ¹

Sci Rep. 2019 Apr 15;9(1):6050. doi: 10.1038/s41598-019-42585-0.

 

Abstract

PfEMP1 is a family of adhesive proteins expressed on the surface of Plasmodium falciparum-infected erythrocytes (IEs), where they mediate adhesion of IEs to a range of host receptors. Efficient PfEMP1-dependent IE sequestration often depends on soluble serum proteins, including IgM. Here, we report a comprehensive investigation of which of the about 60 var gene-encoded PfEMP1 variants per parasite genome can bind IgM via the Fc part of the antibody molecule, and which of the constituent domains of those PfEMP1 are involved. We erased the epigenetic memory of var gene expression in three distinct P. falciparum clones, 3D7, HB3, and IT4/FCR3 by promoter titration, and then isolated individual IEs binding IgM from malaria-unexposed individuals by fluorescence-activated single-cell sorting. The var gene transcription profiles of sub-clones measured by real-time qPCR were used to identify potential IgM-binding PfEMP1 variants. Recombinant DBL and CIDR domains corresponding to those variants were tested by ELISA and protein arrays to confirm their IgM-binding capacity. Selected DBL domains were used to raise specific rat anti-sera to select IEs with uniform expression of candidate PfEMP1 proteins. Our data document that IgM-binding PfEMP1 proteins are common in each of the three clones studied, and that the binding epitopes are mainly found in DBLε and DBLζ domains near the C-terminus.

29. Ten simple rules for organizing a webinar series.

Fadlelmola FM, Panji S, Ahmed AE, Ghouila A, Akurugu WA, Domelevo Entfellner JB, Souiai O, Mulder N; H3ABioNet Research working group as members of the H3Africa Consortium.

PLoS Comput Biol. 2019 Apr 1;15(4):e1006671. doi: 10.1371/journal.pcbi.1006671. eCollection 2019 Apr. No abstract available. Erratum in: PLoS Comput Biol. 2019 May 8;15(5):e1007048

Abstract

No abstract is available for this item.

May

30.  Notes on Distribution of Simulium Damnosum S. L. Along Atbara River in Galabat Sub-Focus, Eastern Sudan

Isam M A Zarroug  ¹ , Arwa Elaagip  ² , Suhaib G Gumaa  ³ , Altayeb K Ali  ⁴ , Ayman Ahmed  ⁵ , Hanaa A M Siam  ⁵ , Deena M Abdelgadir  ⁶ , Olabanji A Surakat  ⁷ , Olatunwa J Olamiju  ⁸ , Daniel A Boakye  ⁹ , Nabil Aziz  ¹⁰ , Kamal Hashim  ¹¹

BMC Infect Dis. 2019 May 28;19(1):477. doi: 10.1186/s12879-019-4113-1.

 

Abstract

Background: Onchocerciasis is caused by a nematode worm Onchocerca volvulus, which is transmitted in Sudan by black fly vectors of the Simulium damnosum sensu lato species complex. In Sudan, the disease is found in four foci where fast flowing rivers provide suitable breeding sites for the Simulium vector flies. The construction of dams and irrigation schemes for agricultural purposes has affected black fly breeding and distribution, such as in Merowe Dam in Abu-Hamed focus, where the perennially flowing water downstream of the Dam created new vector breeding sites, thereby, changing the pattern of disease transmission and creating public health problems. Based on this situation, this study was carried out to measure the effect of the Upper Atbara and Setit Dam complex on the distribution of Simulium damnosum s.l. breeding sites and on disease elimination in the Galabat sub-focus in eastern Sudan.

Methods: Aquatic stages of Simulium were collected between October and November 2009, prior to the construction of the dam complex, and again in 2013 and 2015 while the dam complex construction was ongoing.

Results: A total of 40 breeding sites were identified at the beginning of the study. After the construction of the dam complex in 2015, seventeen previously mapped breeding sites were inaccessible as they had been flooded by the dam complex's lake when reach its maximum size. Three species were obtained from different locations: S. damnosum s.l., S. griseicolle, and S. adersi.

Conclusions: This study has shown a link between the construction of the dam complex and a reduction in the breeding sites of black fly vectors. This reduction has limited the Galabat sub-focus to a small area at the upper Atbara River which become the end of the focus. To sustain the success achieved in onchocerciasis control in the Galabat sub-focus, disease control and its vector control should be strengthened in the area cross-boarding Sudan and Ethiopia.

31.  Using Mobile Health to Support Clinical Decision-Making to Improve Maternal and Neonatal Health Outcomes in Ghana: Insights of Frontline Health Worker Information Needs

Hannah Brown Amoakoh  ^{1   2} , Kerstin Klipstein-Grobusch  ^{2   3} , Diederick E Grobbee  ² , Mary Amoakoh-Coleman  ^{2   4} , Ebenezer Oduro-Mensah  ⁵ , Charity Sarpong  ⁶ , Edith Frimpong  ⁷ , Gbenga A Kayode  ² , Irene Akua Agyepong  ⁸ , Evelyn K Ansah  ⁹

JMIR Mhealth Uhealth. 2019 May 24;7(5):e12879. doi: 10.2196/12879.

 

Abstract

Background: Developing and maintaining resilient health systems in low-resource settings like Ghana requires innovative approaches that adapt technology to context to improve health outcomes. One such innovation was a mobile health (mHealth) clinical decision-making support system (mCDMSS) that utilized text messaging (short message service, SMS) of standard emergency maternal and neonatal protocols via an unstructured supplementary service data (USSD) on request of the health care providers. This mCDMSS was implemented in a cluster randomized controlled trial (CRCT) in the Eastern Region of Ghana.

Objective: This study aimed to analyze the pattern of requests made to the USSD by health workers (HWs). We assessed the relationship between requests made to the USSD and types of maternal and neonatal morbidities reported in health facilities (HFs).

Methods: For clusters in the intervention arm of the CRCT, all requests to the USSD during the 18-month intervention period were extracted from a remote server, and maternal and neonatal health outcomes of interest were obtained from the District Health Information System of Ghana. Chi-square and Fisher exact tests were used to compare the proportion and type of requests made to the USSD by cluster, facility type, and location; whether phones accessing the intervention were shared facility phones or individual-use phones (type-of-phone); or whether protocols were accessed during the day or at night (time-of-day). Trends in requests made were analyzed over 3 6-month periods. The relationship between requests made and the number of cases reported in HFs was assessed using Spearman correlation.

Results: In total, 5329 requests from 72 (97%) participating HFs were made to the intervention. The average number of requests made per cluster was 667. Requests declined from the first to the third 6-month period (44.96% [2396/5329], 39.82% [2122/5329], and 15.22% [811/5329], respectively). Maternal conditions accounted for the majority of requests made (66.35% [3536/5329]). The most frequently accessed maternal conditions were postpartum hemorrhage (25.23% [892/3536]), other conditions (17.82% [630/3536]), and hypertension (16.49% [583/3536]), whereas the most frequently accessed neonatal conditions were prematurity (20.08% [360/1793]), sepsis (15.45% [277/1793]), and resuscitation (13.78% [247/1793]). Requests made to the mCDMSS varied significantly by cluster, type of request (maternal or neonatal), facility type and its location, type-of-phone, and time-of-day at 6-month interval (P<.001 for each variable). Trends in maternal and neonatal requests showed varying significance over each 6-month interval. Only asphyxia and sepsis cases showed significant correlations with the number of requests made (r=0.44 and r=0.79; P<.001 and P=.03, respectively).

Conclusions: There were variations in the pattern of requests made to the mCDMSS over time. Detailed information regarding the use of the mCDMSS provides insight into the information needs of HWs for decision-making and an opportunity to focus support for HW training and ultimately improved maternal and neonatal health.

32.  Concentration and Avidity of Antibodies to Different Circumsporozoite Epitopes Correlate With RTS,S/AS01E Malaria Vaccine Efficacy

Carlota Dobaño  ^{1   2} , Hèctor Sanz  ³ , Hermann Sorgho  ⁴ , David Dosoo  ⁵ , Maximilian Mpina  ^{6   7   8} , Itziar Ubillos  ³ , Ruth Aguilar  ³ , Tom Ford  ⁹ , Núria Díez-Padrisa  ³ , Nana Aba Williams  ³ , Aintzane Ayestaran  ³ , Ousmane Traore  ⁴ , Augusto J Nhabomba  ¹⁰ , Chenjerai Jairoce  ¹⁰ , John Waitumbi  ¹¹ , Selidji Todagbe Agnandji  ^{12   13} , Simon Kariuki  ¹⁴ , Salim Abdulla  ⁶ , John J Aponte  ^{3   10} , Benjamin Mordmüller  ¹³ , Kwaku Poku Asante  ⁵ , Seth Owusu-Agyei  ⁵ , Halidou Tinto  ⁴ , Joseph J Campo  ^{3   10} , Gemma Moncunill  ^{3   10} , Ben Gyan  ^{5   15} , Clarissa Valim  ^{16   17   18} , Claudia Daubenberger  ^{7   8}

Nat Commun. 2019 May 15;10(1):2174. doi: 10.1038/s41467-019-10195-z.

 

Abstract

RTS,S/AS01E has been tested in a phase 3 malaria vaccine study with partial efficacy in African children and infants. In a cohort of 1028 subjects from one low (Bagomoyo) and two high (Nanoro, Kintampo) malaria transmission sites, we analysed IgG plasma/serum concentration and avidity to CSP (NANP-repeat and C-terminal domains) after a 3-dose vaccination against time to clinical malaria events during 12-months. Here we report that RTS,S/AS01E induces substantial increases in IgG levels from pre- to post-vaccination (p < 0.001), higher in NANP than C-terminus (2855 vs 1297 proportional change between means), and higher concentrations and avidities in children than infants (p < 0.001). Baseline CSP IgG levels are elevated in malaria cases than controls (p < 0.001). Both, IgG magnitude to NANP (hazard ratio [95% confidence interval] 0.61 [0.48-0.76]) and avidity to C-terminus (0.07 [0.05-0.90]) post-vaccination are significantly associated with vaccine efficacy. IgG avidity to the C-terminus emerges as a significant contributor to RTS,S/AS01E-mediated protection.

33.  Plasmodium Falciparum Sexual Differentiation in Malaria Patients Is Associated With Host Factors and GDV1-dependent Genes

Miho Usui  ^{1   2   3} , Surendra K Prajapati  ⁴ , Ruth Ayanful-Torgby  ⁵ , Festus K Acquah  ⁵ , Elizabeth Cudjoe  ⁵ , Courage Kakaney  ⁵ , Jones A Amponsah  ⁵ , Evans K Obboh  ⁶ , Deepti K Reddy  ⁴ , Michelle C Barbeau  ⁴ , Lacy M Simons  ⁷ , Beata Czesny  ⁷ , Sorana Raiciulescu  ⁴ , Cara Olsen  ⁴ , Benjamin K Abuaku  ⁵ , Linda E Amoah  ⁵ , Kim C Williamson  ^{4   7   8}

 

M Usui et al. Nat Commun 10 (1), 2740. 2019. PMID 31227704.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Abstract

Plasmodium sexual differentiation is required for malaria transmission, yet much remains unknown about its regulation. Here, we quantify early gametocyte-committed ring (gc-ring) stage, P. falciparum parasites in 260 uncomplicated malaria patient blood samples 10 days before maturation to transmissible stage V gametocytes using a gametocyte conversion assay (GCA). Seventy six percent of the samples have gc-rings, but the ratio of gametocyte to asexual-committed rings (GCR) varies widely (0-78%). GCR correlates positively with parasitemia and is negatively influenced by fever, not hematocrit, age or leukocyte counts. Higher expression levels of GDV1-dependent genes, ap2-g, msrp1 and gexp5, as well as a gdv1 allele encoding H²¹⁷ are associated with high GCR, while high plasma lysophosphatidylcholine levels are associated with low GCR in the second study year. The results provide a view of sexual differentiation in the field and suggest key regulatory roles for clinical factors and gdv1 in gametocytogenesis in vivo.

34.  Risk Factors Associated With Gonorrhea and Chlamydia Transmission in Selected Health Facilities in Ghana

Helena Dela  ¹ , Naiki Attram  ² , Eric Behene  ³ , Selassie Kumordjie  ³ , Kwasi Kennedy Addo  ³ , Edward Owusu Nyarko  ⁴ , Nicholas N A Kyei  ⁴ , John Nii Ayite Carroll  ⁵ , Cynthia Kwakye  ⁶ , Christopher Anthony Duplessis  ⁷ , Nehkonti Adams  ⁷ , Eric Garges  ⁸ , Andrew Gordon Letizia  ²

BMC Infect Dis. 2019 May 16;19(1):425. doi: 10.1186/s12879-019-4035-y.

 

Abstract

Background: Understanding the underlying epidemiology that shapes Neisseria gonorrhoeae (GC), and Chlamydia trachomatis (CT) infections can contribute to data driven policies directed towards curbing the proliferation of these pathogens in Ghana. Information on the symptoms and risk factors for STIs will help to identify high-risk individuals which will in turn inform STI syndromic management and tailor the use of public health resources.

Methods: Participants were from 4 military clinics and 1 civilian STI clinic in Ghana and eligible if they had symptoms suggestive of STI. First void urine samples were collected and tested with Nucleic Acid Amplification Test (NAAT). A structured questionnaire was administered to all participants. Multivariate logistic regression identified factors associated with infection, separately for NG and for CT and for men and women.

Results: A total of 950 patients, 58% of whom were females were enrolled, 28% had gonorrhea and 11% had chlamydia with more males testing positive than females. Reported symptoms that were more common among patients who tested positive for gonorrhea were painful urination and urethral discharge (all P values < 0.05). Additionally, multiple sexual partners and alcohol use were statistically associated with higher rates of gonorrhea in males while only the frequency of condom use was associated with gonorrhea for females. None of the symptoms or risk factors except marital status was associated with testing positive for chlamydia.

Conclusion: Identifying these symptoms and risk factors help inform health care delivery systems for STIs in Ghana. Furthermore, men and women presenting with these symptoms and risk factors are a prime target for public health education campaigns, aimed at curbing the spread of gonorrhea and chlamydia infections.

35.  Impact of Hemoglobin S Trait on Cell Surface Antibody Recognition of Plasmodium falciparum-Infected Erythrocytes in Pregnancy-Associated Malaria

Margaux Chauvet  ^{1   2} , Marilou Tétard  ³ , Gilles Cottrell  ^{1   4} , Florentin Aussenac  ⁴ , Emeline Brossier  ¹ , Luc Denoyel  ¹ , Marion Hanny  ¹ , Murielle Lohezic  ^{1   2} , Jacqueline Milet  ¹ , Nicaise Tuikue Ndam  ^{1   2   5} , Damien Pineau  ¹ , Jocelyne Roman  ¹ , Adrian J F Luty  ^{1   2   4} , Benoît Gamain  ³ , Florence Migot-Nabias  ^{1   2} , Anaïs Merckx  ^{1   2}

PLoS One. 2019 May 31;14(5):e0217422. doi: 10.1371/journal.pone.0217422. eCollection 2019

Abstract

Background: Sickle cell trait (HbAS) confers partial protection against malaria by reducing the adhesion of Plasmodium falciparum-infected erythrocytes to host receptors, but little is known about its potential protection against placental malaria.

Methods: Using flow cytometry, we assessed the recognition of HbAA and HbAS VAR2CSA-expressing infected erythrocytes, by plasma from 159 Beninese pregnant women with either HbAA (normal) or HbAS. Using multivariate linear models adjusted for gravidity, parasite infection at delivery, glucose-6-phosphate dehydrogenase deficiency, and α-thalassemia carriage, we observed significantly reduced cell surface antibody binding of HbAS-infected erythrocytes by plasma from HbAS compared with HbAA women (P < 10^-3).

Results: The difference in cell surface antibody binding was only observed when infected erythrocytes and plasma were associated according to the same hemoglobin genotype. Similar levels of VAR2CSA-specific antibody were measured by enzyme-linked immunosorbent assay in the 2 groups, suggesting that the altered interaction between VAR2CSA and HbAS women's antibodies could reflect abnormal display of VAR2CSA on HbAS erythrocytes.

Conclusions: Our data stress the need for assessments of erythrocyte disorders such as the sickle cell trait in a population group when studying immunological responses to P falciparum.

36.  Sub-genotype Phylogeny of the non-G, non-P Genes of Genotype 2 Rotavirus A Strains

Chantal Ama Agbemabiese  ^{1   2} , Toyoko Nakagomi  ² , Susan Afua Damanka  ¹ , Francis Ekow Dennis  ¹ , Belinda Larteley Lartey  ¹ , George Enyimah Armah  ¹ , Osamu Nakagomi  ²

Open Forum Infect Dis. 2019 Mar 29;6(4):ofz156. doi: 10.1093/ofid/ofz156. eCollection 2019 Apr. PMID:31041352

 

Abstract

Recent increase in the detection of unusual G1P[8], G3P[8], G8P[8], and G9P[4] Rotavirus A (RVA) strains bearing the DS-1-like constellation of the non-G, non-P genes (hereafter referred to as the genotype 2 backbone) requires better understanding of their evolutionary relationship. However, within a genotype, there is lack of a consensus lineage designation framework and a set of common sequences that can serve as references. Phylogenetic analyses were carried out on over 8,500 RVA genotype 2 genes systematically retrieved from the rotavirus database within the NCBI Virus Variation Resource. In line with previous designations, using pairwise comparison of cogent nucleotide sequences and stringent bootstrap support, reference lineages were defined. This study proposes a lineage framework and provides a dataset ranging from 34 to 145 sequences for each genotype 2 gene for orderly lineage designation of global genotype 2 genes of RVAs detected in human and animals. The framework identified five to 31 lineages depending on the gene. The least number of lineages (five to seven) were observed in genotypes A2 (NSP1), T2 (NSP3) and H2 (NSP5) which are limited to human RVA whereas the most number of lineages (31) was observed in genotype E2 (NSP4). Sharing of the same lineage constellations of the genotype 2 backbone genes between recently-emerging, unusual G1P[8], G3P[8], G8P[8] and G9P[4] reassortants and many contemporary G2P[4] strains provided strong support to the hypothesis that unusual genotype 2 strains originated primarily from reassortment events in the recent past involving contemporary G2P[4] strains as one parent and ordinary genotype 1 strains or animal RVA strains as the other. The lineage framework with selected reference sequences will help researchers to identify the lineage to which a given genotype 2 strain belongs, and trace the evolutionary history of common and unusual genotype 2 strains in circulation.

JUNE

37. Genetic Analysis of Ghanaian G1P[8] and G9P[8] Rotavirus A Strains Reveals the Impact of P[8] VP4 Gene Polymorphism on P-genotyping

Susan Afua Damanka  ¹ , Chantal Ama Agbemabiese  ¹ , Francis Ekow Dennis  ¹ , Belinda Larteley Lartey  ¹ , Theophilus Korku Adiku  ² , Christabel Chika Enweronu-Laryea  ³ , George Enyimah Armah  ¹

PLoS One. 2019 Jun 26;14(6):e0218790. doi: 10.1371/journal.pone.0218790. eCollection 2019.

 

38. Therapeutic Efficacy of Artesunate-Amodiaquine and Artemether-Lumefantrine Combinations for Uncomplicated Malaria in 10 Sentinel Sites Across Ghana: 2015-2017

Benjamin Abuaku  ¹ , Nancy O Duah-Quashie  ² , Lydia Quaye  ² , Sena A Matrevi  ² , Neils Quashie  ^{2   3} , Akosua Gyasi  ⁴ , Felicia Owusu-Antwi  ⁵ , Keziah Malm  ⁴ , Kwadwo Koram  ²

Malar J. 2019 Jun 24;18(1):206. doi: 10.1186/s12936-019-2848-1.

PMID:31234874

Abstract

Background: Routine surveillance on the therapeutic efficacy of artemisinin-based combination therapy (ACT) has been ongoing in Ghana since 2005. The sixth round of surveillance was conducted between 2015 and 2017 to determine the therapeutic efficacy of artesunate-amodiaquine (AS-AQ) and artemether-lumefantrine (AL) in 10 sentinel sites across the country.

Methods: The study was a one-arm, prospective, evaluation of the clinical, parasitological, and haematological responses to directly observed treatment with AS-AQ and AL among children 6 months to 9 years old with uncomplicated falciparum malaria. The WHO 2009 protocol on surveillance of anti-malaria drug efficacy was used for the study with primary outcomes as prevalence of day 3 parasitaemia and clinical and parasitological cure rates on day 28. Secondary outcomes assessed included patterns of fever and parasite clearance as well as changes in haemoglobin concentration.

Results: Day 3 parasitaemia was absent in all sites following treatment with AS-AQ whilst only one person (0.2%) was parasitaemic on day 3 following treatment with AL. Day 28 PCR-corrected cure rates following treatment with AS-AQ ranged between 96.7% (95% CI 88.5-99.6) and 100%, yielding a national rate of 99.2% (95% CI 97.7-99.7). Day 28 PCR-corrected cure rates following treatment with AL ranged between 91.3% (95% CI 79.2-97.6) and 100%, yielding a national rate of 96% (95% CI 93.5-97.6). Prevalence of fever declined by 88.4 and 80.4% after first day of treatment with AS-AQ and AL, respectively, whilst prevalence of parasitaemia on day 2 was 2.1% for AS-AQ and 1.5% for AL. Gametocytaemia was maintained at low levels (< 5%) during the 3 days of treatment. Post-treatment mean haemoglobin concentration was significantly higher than pre-treatment concentration following treatment with either AS-AQ or AL.

Conclusions: The therapeutic efficacy of AS-AQ and AL is over 90% in sentinel sites across Ghana. The two anti-malarial drugs therefore remain efficacious in the treatment of uncomplicated malaria in the country and continue to achieve rapid fever and parasite clearance as well as low gametocyte carriage rates and improved post-treatment mean haemoglobin concentration.

Keywords: Artemether–lumefantrine; Artesunate–amodiaquine; Ghana; Sentinel sites; Therapeutic efficacy; Uncomplicated malaria.

39. Genetic analysis of Ghanaian G1P[8] and G9P[8] rotavirus A strains reveals the impact of P[8] VP4 gene polymorphism on P-genotyping.

Damanka SA, Agbemabiese CA, Dennis FE, Lartey BL, Adiku TK, Enweronu-Laryea CC, Armah GE.

PLoS One. 2019 Jun 26;14(6):e0218790. doi: 10.1371/journal.pone.0218790. eCollection 2019. PMID:31242245

Abstract

The World Health Organisation rotavirus surveillance networks have documented and shown eclectic geographic and temporal diversity in circulating G- and P- genotypes identified in children <5 years of age. To effectively monitor vaccine performance and effectiveness, robust molecular and phylogenetic techniques are essential to detect novel strain variants that might emerge due to vaccine pressure. This study inferred the phylogenetic history of the VP7 and VP4 genes of previously non-typeable strains and provided insight into the diversity of P[8] VP4 sequences which impacted the outcome of our routine VP4 genotyping method. Near-full-length VP7 gene and the VP8* fragment of the VP4 gene were obtained by Sanger sequencing and genotypes were determined using RotaC v2.0 web-based genotyping tool. The genotypes of the 57 rotavirus-positive samples with sufficient stool was determined. Forty-eight of the 57 (84.2%) had the P[8] specificity, of which 43 (89.6%) were characterized as P[8]a subtype and 5 (10.4%) as the rare OP354-like subtype. The VP7 gene of 27 samples were successfully sequenced and their G-genotypes confirmed as G1 (18/27) and G9 (9/27). Phylogenetic analysis of the P[8]a sequences placed them in subcluster IIIc within lineage III together with contemporary G1P[8], G3P[8], G8P[8], and G9P[8] strains detected globally from 2006–2016. The G1 VP7 sequences of the study strains formed a monophyletic cluster with African G1P[8] strains, previously detected in Ghana and Mali during the RotaTeq vaccine trial as well as Togo. The G9 VP7 sequences of the study strains formed a monophyletic cluster with contemporary African G9 sequences from neighbouring Burkina Faso within the major sub-cluster of lineage III. Mutations identified in the primer binding region of the VP8* sequence of the Ghanaian P[8]a strains may have resulted in the genotyping failure since the newly designed primer successfully genotyped the previously non-typeable P[8] strains. In summary, the G1, G9, and P[8]a sequences were highly similar to contemporary African strains at the lineage level. The study also resolved the methodological challenges of the standard genotyping techniques and highlighted the need for regular evaluation of the multiplex PCR-typing method especially in the post-vaccination era. The study further highlights the need for regions to start using sequencing data from local rotavirus strains to design and update genotyping primers.

 

40. Molecular Informatics Studies of the Iron-Dependent Regulator (ideR) Reveal Potential Novel Anti- Mycobacterium ulcerans Natural Product-Derived Compounds

Samuel K Kwofie  ^{1   2   3} , Kweku S Enninful  ^{4   5} , Jaleel A Yussif  ⁶ , Lina A Asante  ⁷ , Mavis Adjei  ⁸ , Kwabena Kan-Dapaah  ⁹ , Elvis K Tiburu  ¹⁰ , Wilhelmina A Mensah  ¹¹ , Whelton A Miller 3rd  ^{12   13   14} , Lydia Mosi  ¹⁵ , Michael D Wilson  ^{16   17}

Molecules. 2019 Jun 21;24(12). pii: E2299. doi: 10.3390/molecules24122299.

PMID:31234337

Abstract

Buruli ulcer is a neglected tropical disease caused by the bacterium Mycobacterium ulcerans. Its virulence is attributed to the dermo-necrotic polyketide toxin mycolactone, whose synthesis is regressed when its iron acquisition system regulated by the iron-dependent regulator (ideR) is deactivated. Interfering with the activation mechanism of ideR to inhibit the toxin's synthesis could serve as a possible cure for Buruli ulcer. The three-dimensional structure of the ideR for Mycobacterium ulcerans was generated using homology modeling. A library of 832 African natural products (AfroDB), as well as five known anti-mycobacterial compounds were docked against the metal binding site of the ideR. The area under the curve (AUC) values greater than 0.7 were obtained for the computed Receiver Operating Characteristics (ROC) curves, validating the docking protocol. The identified top hits were pharmacologically profiled using Absorption, Distribution, Metabolism, Elimination and Toxicity (ADMET) predictions and their binding mechanisms were characterized. Four compounds with ZINC IDs ZINC000018185774, ZINC000095485921, ZINC000014417338 and ZINC000005357841 emerged as leads with binding energies of -7.7 kcal/mol, -7.6 kcal/mol, -8.0 kcal/mol and -7.4 kcal/mol, respectively. Induced Fit Docking (IFD) was also performed to account for the protein's flexibility upon ligand binding and to estimate the best plausible conformation of the complexes. Results obtained from the IFD were consistent with that of the molecular docking with the lead compounds forming interactions with known essential residues and some novel critical residues Thr14, Arg33 and Asp17. A hundred nanoseconds molecular dynamic simulations of the unbound ideR and its complexes with the respective lead compounds revealed changes in the ideR's conformations induced by ZINC000018185774. Comparison of the lead compounds to reported potent inhibitors by docking them against the DNA-binding domain of the protein also showed the lead compounds to have very close binding affinities to those of the potent inhibitors. Interestingly, structurally similar compounds to ZINC000018185774 and ZINC000014417338, as well as analogues of ZINC000095485921, including quercetin are reported to possess anti-mycobacterial activity. Also, ZINC000005357841 was predicted to possess anti-inflammatory and anti-oxidative activities, which are relevant in Buruli ulcer and iron acquisition mechanisms, respectively. The leads are molecular templates which may serve as essential scaffolds for the design of future anti-mycobacterium ulcerans agents.

Keywords: DNA–binding site; Mycobacterium ulcerans; buruli ulcer; iron dependent regulator (ideR); metal binding site; molecular docking; molecular dynamics simulation; natural product compounds.

41. Plasmodium falciparum sexual differentiation in malaria patients is associated with host factors and GDV1-dependent genes.

Usui M, Prajapati SK, Ayanful-Torgby R, Acquah FK, Cudjoe E, Kakaney C, Amponsah JA, Obboh EK, Reddy DK, Barbeau MC, Simons LM, Czesny B, Raiciulescu S, Olsen C, Abuaku BK, Amoah LE, Williamson KC.

Nat Commun. 2019 Jun 21;10(1):2740. doi: 10.1038/s41467-019-10805-w.

PMID:31227704

Abstract

Plasmodium sexual differentiation is required for malaria transmission, yet much remains unknown about its regulation. Here, we quantify early gametocyte-committed ring (gc-ring) stage, P. falciparum parasites in 260 uncomplicated malaria patient blood samples 10 days before maturation to transmissible stage V gametocytes using a gametocyte conversion assay (GCA). Seventy six percent of the samples have gc-rings, but the ratio of gametocyte to asexual-committed rings (GCR) varies widely (0–78%). GCR correlates positively with parasitemia and is negatively influenced by fever, not hematocrit, age or leukocyte counts. Higher expression levels of GDV1-dependent genes, ap2-g, msrp1 and gexp5, as well as a gdv1 allele encoding H217 are associated with high GCR, while high plasma lysophosphatidylcholine levels are associated with low GCR in the second study year. The results provide a view of sexual differentiation in the field and suggest key regulatory roles for clinical factors and gdv1 in gametocytogenesis in vivo.

 

42. Current and Novel Approaches in Influenza Management

Erasmus Kotey  ^{1   2   3} , Deimante Lukosaityte  ^{4   5} , Osbourne Quaye  ^{6   7} , William Ampofo  ⁸ , Gordon Awandare  ^{9   10} , Munir Iqbal  ¹¹

Vaccines (Basel). 2019 Jun 18;7(2). pii: E53. doi: 10.3390/vaccines7020053. Review.

PMID:31216759

Abstract

Influenza is a disease that poses a significant health burden worldwide. Vaccination is the best way to prevent influenza virus infections. However, conventional vaccines are only effective for a short period of time due to the propensity of influenza viruses to undergo antigenic drift and antigenic shift. The efficacy of these vaccines is uncertain from year-to-year due to potential mismatch between the circulating viruses and vaccine strains, and mutations arising due to egg adaptation. Subsequently, the inability to store these vaccines long-term and vaccine shortages are challenges that need to be overcome. Conventional vaccines also have variable efficacies for certain populations, including the young, old, and immunocompromised. This warrants for diverse efficacious vaccine developmental approaches, involving both active and passive immunization. As opposed to active immunization platforms (requiring the use of whole or portions of pathogens as vaccines), the rapidly developing passive immunization involves administration of either pathogen-specific or broadly acting antibodies against a kind or class of pathogens as a treatment to corresponding acute infection. Several antibodies with broadly acting capacities have been discovered that may serve as means to suppress influenza viral infection and allow the process of natural immunity to engage opsonized pathogens whilst boosting immune system by antibody-dependent mechanisms that bridge the innate and adaptive arms. By that; passive immunotherapeutics approach assumes a robust tool that could aid control of influenza viruses. In this review, we comment on some improvements in influenza management and promising vaccine development platforms with an emphasis on the protective capacity of passive immunotherapeutics especially when coupled with the use of antivirals in the management of influenza infection.

Keywords: Influenza virus; immunotherapeutics; passive immunization; vaccines.

43. Core Encoding Sequences of Hepatitis C Virus in Ghanaian Blood Donors Are Predominantly Mosaics of Different Genotype 2 Strains and Cannot Distinguish Subtypes

Nicholas Israel Nii-Trebi  ¹ , Charles Addoquaye Brown  ² , Yaa Difie Osei  ³ , William Kwabena Ampofo  ⁴ , Alexander Kwadwo Nyarko  ⁵

BMC Infect Dis. 2019 Jun 17;19(1):533. doi: 10.1186/s12879-019-4155-4.

PMID:31208352

 

Abstract

Background: Distribution of Hepatitis C virus (HCV) genotypes varies significantly worldwide. Genomic diversity between genotypes has implications for treatment, vaccine development and optimal design of HCV diagnostic assays. Molecular characterization of HCV in different geographical areas is therefore very essential for management and public health control of HCV infection. This study investigated the molecular epidemiology and characteristics of HCV genotypes in healthy individuals in Accra, Ghana.

Methods: An experimental study was carried out on blood samples obtained from voluntary blood donors. Two hundred samples were initially screened for HCV antibodies and infection was confirmed by RNA detection through RT-PCR of the 5'-untranslated region (5'UTR). The core gene sequences were analysed for HCV genotype determination by genotype-specific PCR; and then by cloning and direct sequencing followed by phylogenetic analysis. The sequences were further analysed in detail by similarity plotting.

Results: Molecular diagnosis confirmed the presence of HCV RNA in 2 out of 200 (1%) blood donors. Initial genotyping by genotype-specific PCR identified all two infections as subtypes 2a and 2b of genotype 2. Extensive evolutionary and genetic analyses indicated two epidemiological profiles. First, phylogenetic tree topologies clearly showed that, collectively, the core sequences of the Ghanaian HCV isolates belong to a single, distinct genetic group within HCV genotype 2 cluster, with high genetic similarity and rapid sequence variation in a single individual. Second, the sequences are mosaics comprising 2e and other genotype 2 subtype fragments. The analyses underscore a unique and complex HCV genotype 2 core sequence profile of the Ghanaian isolates.

Conclusions: Analysis of HCV core encoding sequences from Ghanaian blood donors in Accra confirmed predominance of genotype 2 HCV among healthy individuals. However, the isolates could not be classified into subtypes, possibly due to their complex sequence pattern that might suggest high mutability of the prevailing genotype. The core region of Ghanaian HCV therefore may not be suitable for distinguishing subtypes. These findings extend those from previous studies and thus underscore the need to search for subtype-informative region of Ghanaian HCV to elucidate the genetic diversity and factors determining outcome of HCV infections in Ghana.

Keywords: Blood donors; Core gene; Genotype; Ghana; HCV; Molecular epidemiology; Seroprevalence.

44. Whole Genome Characterization and Evolutionary Analysis of OP354-like P[8] Rotavirus A Strains Isolated From Ghanaian Children With Diarrhoea

Susan Afua Damanka  ¹ , Sabina Kwofie  ^{1   2} , Francis Ekow Dennis  ¹ , Belinda Larteley Lartey  ¹ , Chantal Ama Agbemabiese  ¹ , Yen Hai Doan  ³ , Theophilus Korku Adiku  ⁴ , Kazuhiko Katayama  ⁵ , Christabel Chika Enweronu-Laryea  ⁶ , George Enyimah Armah  ¹

PLoS One. 2019 Jun 14;14(6):e0218348. doi: 10.1371/journal.pone.0218348. eCollection 2019. PMID:31199823

Abstract

In 2010, the rare OP354-like P[8]b rotavirus subtype was detected in children less than 2 years old in Ghana. In this follow-up study, to provide insight into the evolutionary history of the genome of Ghanaian P[8]b strains RVA/Human-wt/GHA/GHDC949/2010/G9P[8] and RVA/Human-wt/GHA/GHM0094/2010/G9P[8] detected in an infant and a 7-month old child hospitalised for acute gastroenteritis, we sequenced the complete genome using both Sanger sequencing and Illumina MiSeq technology followed by phylogenetic analysis of the near-full length sequences. Both strains possessed the Wa-like/genotype 1 constellation G9P[8]b-I1-R1-C1-M1-A1-N1-T1-E1-H1. Sequence comparison and phylogenetic inference showed that both strains were identical at the lineage level throughout the 11 genome segments. Their VP7 sequences belonged to the major sub-lineage of the G9-lineage III whereas their VP4 sequences belonged to P[8]b cluster I. The VP7 and VP4 genes of the study strains were closely related to a Senegalese G9P[8]b strain detected in 2009. In the remaining nine genome segments, both strains consistently clustered together with Wa-like RVA strains possessing either P[8]a or P[8]b mostly of African RVA origin. The introduction of a P[8]b subtype VP4 gene into the stable Wa-like strain backbone may result in strains that might propagate easily in the human population, with a potential to become an important public health concern, especially because it is not certain if the monovalent rotavirus vaccine (Rotarix) used in Ghana will be efficacious against such strains. Our analysis of the full genomes of GHM0094 and GHDC949 adds to knowledge of the genetic make-up and evolutionary dynamics of P[8]b rotavirus strains.

45. Antigenicity and Immune Correlate Assessment of Seven Plasmodium Falciparum Antigens in a Longitudinal Infant Cohort From Northern Ghana

Kwadwo Asamoah Kusi  ¹ , Joao Aguiar  ² , Selassie Kumordjie  ³ , Felix Aggor  ^{3   4} , Jessica Bolton  ² , Andrea Renner  ^{2   5} , Eric Kyei-Baafour  ³ , Naiki Puplampu  ⁶ , Maria Belmonte  ² , Daniel Dodoo  ³ , Ben Adu Gyan  ³ , Michael Fokuo Ofori  ³ , Abraham Rex Oduro  ⁷ , Frank Atuguba  ⁷ , Kwadwo Ansah Koram  ⁸ , Nehkonti Adams  ^{6   9} , Andrew Letizia  ⁶ , Eileen Villasante  ² , Martha Sedegah  ²

Sci Rep. 2019 Jun 13;9(1):8621. doi: 10.1038/s41598-019-45092-4.

PMID:31197225

Abstract

The current global malaria control and elimination agenda requires development of additional effective disease intervention tools. Discovery and characterization of relevant parasite antigens is important for the development of new diagnostics and transmission monitoring tools and for subunit vaccine development. This study assessed the natural antibody response profile of seven novel Plasmodium falciparum pre-erythrocytic antigens and their potential association with protection against clinical malaria. Antigen-specific antibody levels in plasma collected at six time points from a longitudinal cohort of one-to-five year old children resident in a seasonal malaria transmission area of northern Ghana were assessed by ELISA. Antibody levels were compared between parasite-positive and parasite-negative individuals and the association of antibody levels with malaria risk assessed using a regression model. Plasma antibody levels against five of the seven antigens were significantly higher in parasite-positive children compared to parasite-negative children, especially during low transmission periods. None of the antigen-specific antibodies showed an association with protection against clinical malaria. The study identified five of the seven antigens as markers of exposure to malaria, and these will have relevance for the development of disease diagnostic and monitoring tools. The vaccine potential of these antigens requires further assessment.

46. High insecticide resistance intensity of Anopheles gambiae (s.l.) and low efficacy of pyrethroid LLINs in Accra, Ghana.

Pwalia R, Joannides J, Iddrisu A, Addae C, Acquah-Baidoo D, Obuobi D, Amlalo G, Akporh S, Gbagba S, Dadzie SK, Athinya DK, Hadi MP, Jamet HP, Chabi J.

Parasit Vectors. 2019 Jun 13;12(1):299. doi: 10.1186/s13071-019-3556-y.

Abstract

Background: Insecticide resistance of Anopheles gambiae (s.l.) against public health insecticides is increasingly reported in Ghana and need to be closely monitored. This study investigated the intensity of insecticide resistance of An. gambiae (s.l.) found in a vegetable growing area in Accra, Ghana, where insecticides, herbicides and fertilizers are massively used for plant protection. The bioefficacy of long-lasting insecticidal nets (LLINs) currently distributed in the country was also assessed to delimitate the impact of the insecticide resistance intensity on the effectiveness of those nets.

Methods: Three- to five-day-old adult mosquitoes that emerged from collected larvae from Opeibea, Accra (Ghana), were assayed using CDC bottle and WHO tube intensity assays against different insecticides. The Vgsc-L1014F and ace-1 mutations within the population were also characterized using PCR methods. Furthermore, cone bioassays against different types of LLINs were conducted to evaluate the extent and impact of the resistance of An. gambiae (s.l.) from Opeibea.

Results: Anopheles gambiae (s.l.) from Opeibea were resistant to all the insecticides tested with very low mortality observed against organochlorine, carbamates and pyrethroid insecticides using WHO susceptibility tests at diagnostic doses during three consecutive years of monitoring. The average frequencies of Vgsc-1014F and ace-1 in the An. gambiae (s.l.) population tested were 0.99 and 0.76, respectively. The intensity assays using both CDC bottle and WHO tubes showed high resistance intensity to pyrethroids and carbamates with survivals at 10× the diagnostic doses of the insecticides tested. Only pirimiphos methyl recorded a low resistance intensity with 100% mortality at 5× the diagnostic dose. The bioefficacy of pyrethroid LLINs ranged from 2.2 to 16.2% mortality while the PBO LLIN, PermaNet^® 3.0, was 73%.

Conclusions: WHO susceptibility tests using the diagnostic doses described the susceptibility status of the mosquito colony while CDC bottle and WHO tube intensity assays showed varying degrees of resistance intensity. Although both methods are not directly comparable, the indication of the resistance intensity showed the alarming insecticide resistance intensity in Opeibea and its surroundings, which could have an operational impact on the efficacy of vector control tools and particularly on pyrethroid LLINs.

Keywords: Anopheles gambiae (s.l.); CDC bottle assay; Insecticide resistance; Intensity assay; WHO susceptibility test.

47. The temporal dynamics and infectiousness of subpatent Plasmodium falciparum infections in relation to parasite density.

Slater HC, Ross A, Felger I, Hofmann NE, Robinson L, Cook J, Gonçalves BP, Björkman A, Ouedraogo AL, Morris U, Msellem M, Koepfli C, Mueller I, Tadesse F, Gadisa E, Das S, Domingo G, Kapulu M, Midega J, Owusu-Agyei S, Nabet C, Piarroux R, Doumbo O, Doumbo SN, Koram K, Lucchi N, Udhayakumar V, Mosha J, Tiono A, Chandramohan D, Gosling R, Mwingira F, Sauerwein R, Paul R, Riley EM, White NJ, Nosten F, Imwong M, Bousema T, Drakeley C, Okell LC.

Nat Commun. 2019 Jun 11;10(1):2644. doi: 10.1038/s41467-019-10790-0.

PMID:31186429

Abstract

Malaria infections occurring below the limit of detection of standard diagnostics are common in all endemic settings. However, key questions remain surrounding their contribution to sustaining transmission and whether they need to be detected and targeted to achieve malaria elimination. In this study we analyse a range of malaria datasets to quantify the density, detectability, course of infection and infectiousness of subpatent infections. Asymptomatically infected individuals have lower parasite densities on average in low transmission settings compared to individuals in higher transmission settings. In cohort studies, subpatent infections are found to be predictive of future periods of patent infection and in membrane feeding studies, individuals infected with subpatent asexual parasite densities are found to be approximately a third as infectious to mosquitoes as individuals with patent (asexual parasite) infection. These results indicate that subpatent infections contribute to the infectious reservoir, may be long lasting, and require more sensitive diagnostics to detect them in lower transmission settings.

48. Arbovirus Circulation Among Febrile Patients at the Greater Accra Regional Hospital, Ghana

Simon Kofi Manu  ^{1   2} , Joseph Humphrey Kofi Bonney  ³ , Deborah Pratt  ² , Farida Njelba Abdulai  ⁴ , Eudosia Esinam Agbosu  ² , Prince Osei Frimpong  ⁴ , Theophilus Korku Adiku  ^{1   5}

BMC Res Notes. 2019 Jun 11;12(1):332. doi: 10.1186/s13104-019-4378-x.

PMID:31186058

Abstract

Objective: Arboviruses, Dengue and Chikungunya have become major international public health concerns due to their epidemics and introduction in new areas. In Ghana, little is known is about Dengue and Chikungunya viruses though the country has been listed as part of the 34 countries in which the viruses are endemic. This has been attributed partly to the lack of diagnostic tools for these viruses in several health facilities and institutions across the country. The purpose of this study was to detect and characterize these viral pathogens among febrile patients in Accra Ghana.

Results: This hospital-based cross-sectional study enrolled 260 suspected Dengue and/or Chikungunya febrile patients who submitted their clinical specimens of serum. Out of the total number tested with both molecular and serological tools, Chikungunya and Dengue specific total antibodies were detected from 72 (27.69%) and 180 (69.23%) respectively. None of the participants tested positive for Dengue and Chikungunya by reverse transcription-polymerase chain reaction (RT-PCR) and with the Dengue-specific NS1 antigen strip kits. Our findings suggested that Dengue and Chikungunya viruses may be circulating but are being missed among febrile patients. Differential diagnosis work-up in febrile patients should be made to include Dengue and Chikungunya infections.

Keywords: Chikungunya; Dengue; Differential diagnosis; Polymerase chain reaction.

49. Serological Evidence of Zika Virus Infection in Febrile Patients at Greater Accra Regional Hospital, Accra Ghana

Godson Aryee Ankrah  ¹ , Joseph Humphrey Kofi Bonney  ² , Esinam Eudosia Agbosu  ³ , Deborah Pratt  ³ , Theophilus Korku Adiku  ^{1   4}

BMC Res Notes. 2019 Jun 10;12(1):326. doi: 10.1186/s13104-019-4371-4.

PMID:31182146

Abstract

Objective: Increase in the evidence of global occurrence of Zika viral infection suggests that in Africa the circulation of the virus which causes 80% of asymptomatic infection could be undetected and/or overlooked. We sought to serologically detect Zika virus infection in febrile patients at Greater Accra Regional Hospital, Ghana.

Results: Of the 160 patient serum samples analyzed, 33 were found to have antibodies against Zika virus infection. Among the sero-positives 30 (91%) of the cases were anti-Zika virus IgM with the 21-30-year age group recording the highest number of 8 (26%) and 2 (7%) cases being the least for the 61 years and above age group. All sero-positive febrile patients developed at least one symptom consistent with Zika virus infection: 33 (100%) fever, 25 (76%) muscle pain, 24 (73%) joint pain, and conjunctivitis 2 (6%). Digestive symptoms recorded include 16 (49%) nausea, 12 (36%) vomiting and diarrhea 18 (55%). In addition, 28 (85%) loss of appetite, 14 (75%) rapid respiration and chest pain 15 (42%) were reported by seropositive febrile patients. Our data indicates exposure to Zika virus which suggests the possible circulation of the virus among febrile patients in Ghana with a sero-prevalence rate of 20.6%.

Keywords: Anti-Zika virus immunoglobulins M and G (IgM and IgG) antibodies; Enzyme linked immunosorbent assay (ELISA); Seroprevalence; Zika virus.

50. The Diversity, Multiplicity of Infection and Population Structure of falciparum Parasites Circulating in Asymptomatic Carriers Living in High and Low Malaria Transmission Settings of Ghana

Zakaria Abukari  ^{1   2} , Ruth Okonu  ³ , Samuel B Nyarko  ⁴ , Aminata C Lo  ^{5   6} , Cheikh C Dieng  ⁷ , Samson P Salifu  ⁸ , Ben A Gyan  ⁹ , Eugenia Lo  ¹⁰ , Linda E Amoah  ^{11   12}

Genes (Basel). 2019 Jun 7;10(6). pii: E434. doi: 10.3390/genes10060434.

PMID:31181699

Abstract

Background: Diversity in Plasmodium falciparum poses a major threat to malaria control and elimination interventions. This study utilized 12 polymorphic microsatellite (MS) markers and the Msp2 marker to examine diversity, multiplicity of infection (MOI) as well as the population structure of parasites circulating in two sites separated by about 92 km and with varying malaria transmission intensities within the Greater Accra Region of Ghana.

Methods: The diversity and MOI of P. falciparum parasites in 160 non-symptomatic volunteers living in Obom (high malaria transmission intensity) and Asutsuare (low malaria transmission intensity) aged between 8 and 60 years was determined using Msp2 genotyping and microsatellite analysis.

Results: The prevalence of asymptomatic P. falciparum carriers as well as the parasite density of infections was significantly higher in Obom than in Asutsuare. Samples from Asutsuare and Obom were 100% and 65% clonal, respectively, by Msp2 genotyping but decreased to 50% and 5%, respectively, when determined by MS analysis. The genetic composition of parasites from Obom and Asutsuare were highly distinct, with parasites from Obom being more diverse than those from Asutsuare.

Conclusion: Plasmodium falciparum parasites circulating in Obom are genetically more diverse and distinct from those circulating in Asutsuare. The MOI in samples from both Obom and Asutsuare increased when assessed by MS analysis relative to MSP2 genotyping. The TA40 and TA87 loci are useful markers for estimating MOI in high and low parasite prevalence settings.

Keywords: MSP2 genotyping; genetic diversity; malaria; microsatellites; multiplicity of infection; parasite.

51. Challenges and Perceptions of Implementing Mass Testing, Treatment and Tracking in Malaria Control: A Qualitative Study in Pakro Sub-District of Ghana

Ignatius Cheng Ndong  ^{1   2} , Daniel Okyere  ³ , Juliana Yartey Enos  ³ , Alfred Amambua-Ngwa  ⁴ , Corinne Simone C Merle  ⁵ , Alexander Nyarko  ^{3   6} , Kwadwo Ansah Koram  ³ , Collins Stephan Ahorlu  ³

BMC Public Health. 2019 Jun 6;19(1):695. doi: 10.1186/s12889-019-7037-1.

PMID:31170964

Abstract

Background: Malaria remains endemic in Ghana despite several interventions. Studies have demonstrated very high levels of asymptomatic malaria parasitaemia in both under-five and school-age children. Mass testing, treatment and tracking (MTTT) of malaria in communities is being proposed for implementation with the argument that it can reduce parasite load, amplify gains from the other control interventions and consequently lead to elimination. However, challenges associated with implementing MTTT such as feasibility, levels of coverage to be achieved for effectiveness, community perceptions and cost implications need to be clearly understood. This qualitative study was therefore conducted in an area with on-going MTTT to assess community and health workers' perceptions about feasibility of scale-up and effectiveness to guide scale-up decisions.

Methods: This qualitative study employed purposive sampling to select the study participants. Ten focus group discussions (FGDs) were conducted in seven communities; eight with community members (n = 80) and two with health workers (n = 14). In addition, two in-depth interviews (IDI) were conducted, one with a Physician Assistant and another with a Laboratory Technician at the health facility. All interviews were recorded, transcribed, translated and analyzed using QSR NVivo 12.

Results: Both health workers and community members expressed positive perceptions about the feasibility of implementation and effectiveness of MTTT as an intervention that could reduce the burden of malaria in the community. MTTT implementation was perceived to have increased sensitisation about malaria, reduced the incidence of malaria, reduced household expenditure on malaria and alleviated the need to travel long distances for healthcare. Key challenges to implementation were doubts about the expertise of trained Community-Based Health Volunteers (CBHVs) to diagnose and treat malaria appropriately, side effects of Artemisinin-based Combination Therapies (ACTs) and misconceptions that CBHVs could infect children with epilepsy.

Conclusion: The study demonstrated that MTTT was perceived to be effective in reducing malaria incidence and related hospital visits in participating communities. MTTT was deemed useful in breaking financial and geographical barriers to accessing healthcare. The interventions were feasible and acceptable to community members, despite observed challenges to implementation such as concerns about CBHVs' knowledge and skills and reduced revenue from internally generated funds (IGF) of the health facility.

Keywords: Challenges; Ghana; Malaria; Perceptions; Test; Treat and track.

52. Population Data of 23 Y Chromosome STR Loci for the Five Major Human Subpopulations of Ghana

Abban Edward Kofi  ^{1   2} , Hashom Mohd Hakim  ^{3   4} , Hussein Omar Khan  ³ , Siti Afifah Ismail  ³ , Anita Ghansah  ⁵ , Agyemang Adjem David  ² , Nor Fazila Che Mat  ¹ , Geoffrey Keith Chambers  ⁶ , Hisham Atan Edinur  ^{7   8   9}

Int J Legal Med. 2019 Jun 1. doi: 10.1007/s00414-019-02099-w. [Epub ahead of print]

PMID:31154498

Abstract

In this study, 268 samples for unrelated males belonging to the five major human subpopulation groups in Ghana (Akan, Ewe, Mole-Dagbon, Ga-Dangme and Guang) were genetically characterised for 23 Y chromosome short tandem repeat (STR) loci using the Powerplex® Y23 STR kit. A total of 263 complete haplotypes were recorded of which 258 were unique. The haplotype diversity, discriminating capacity and match probability for the pooled population data were 0.9998, 0.9627 and 0.0039, respectively. The pairwise genetic distance (R_ST) for the Ghanaian datasets and other reference populations deposited in the Y-STR Haplotype Reference Database (YHRD) were estimated and mapped using multidimensional scaling (MDS) plot. The Guang and Ewe were significantly different from the Akan, Mole-Dagbon and Ga-Dangme. However, the five Ghanaian datasets were all plotted close together with other African populations in the MDS data mapping.

Keywords: Forensic science; Ghana; Haplotypes; Population genetics; Y chromosome STR.

53. Molecular Detection of Enterovirus D68 Among Children With Acute Respiratory Tract Infection in Ghana

Joyce A Kubi  ^{1   2} , Mohamed Mutocheluh  ¹ , Joseph H K Bonney  ² , William K Ampofo  ² , John K Odoom  ²

Afr J Lab Med. 2019 Jun 26;8(1):732. doi: 10.4102/ajlm.v8i1.732. eCollection 2019.

PMID:31309045

Abstract

Background: Acute respiratory tract infections of viral origin remain a leading cause of morbidity, mortality and economic loss regardless of age or gender. A small number of acute respiratory tract infection cases caused by enterovirus D68 (EV-D68) have been reported regularly to Centers for Disease Control and Prevention since 1987 by countries in North America, Europe and Asia. However, in 2014 and 2015, the number of reported confirmed EV-D68 infections was much greater than in previous years. The National Influenza Centre (NIC), Ghana carries out surveillance of respiratory infections, focusing on those caused by influenza virus; however, there is inadequate information on other viruses causing respiratory infections in Ghana, including EV-D68.

Objectives: To investigate the association of EV-D68 with Severe Acute Respiratory Infections (SARI) and Influenza-Like Illness (ILI) in Ghana.

Methods: This was a retrospective cross-sectional study which involved archived human respiratory specimens stored at -80 °C at the NIC from 2014 to 2015. Using a random sampling method, oropharyngeal and nasopharyngeal swabs from patients with SARI and ILI that were negative by real-time PCR for human influenza viruses were screened for EV-D68 using real-time reverse transcription-polymerase chain reaction (rRT-PCR).

Results: Enterovirus D68 was detected in 4 (2.2%) out of 182 SARI samples tested. EV-D68 was detected in children younger than 5 years (4 - 100% of positives) and was not detected in children older than 5 years. Enterovirus D68 was detected more frequently in SARI cases (3%) than in ILI cases (1.2%).

Conclusion: This study has shown for the first time the presence of EV-D68 in acute respiratory infections in Ghana. The results confirmed minimal EV-D68 circulation in the Ghanaian population.

Keywords: EV-D68; Ghana; acute; respiratory tract infection.

54. Malaria Vaccine Deployment in Africa: Focus on Ghana

Kwaku Poku Asante  ¹ , Fred N Binka  ² , Kwadwo A Koram  ³

Ghana Med J. 2019 Jun;53(2):90-91. doi: 10.4314/gmj.v53i2.2. No abstract available.

PMID:31481803

Abstract:

The announcement by the Ghana Health Service /Ministry of Health at the beginning of May to begin the pilot implementation of the malaria vaccine – RTS,S/AS01 (Mosquirix®) – manufactured by GSK Biologicals was greeted with rumours about conspiracy theories of secret agenda to depopulate Africa through the use of vaccines and all the other stories that are often propagated by the anti vaxxers. This was not unlike the fear and panic spread throughout the country that prevented investigators from conducting clinical trials on new vaccines against the Ebola virus disease a few years

Phenotypic Evidence of T Cell Exhaustion and Senescence During Symptomatic Plasmodium falciparum Malaria

Augustina Frimpong  ^{1   2   3} , Kwadwo Asamoah Kusi  ^{1   2} , Dennis Adu-Gyasi  ⁴ , Jones Amponsah  ² , Michael Fokuo Ofori  ^{1   2} , Wilfred Ndifon  ^{3   5}

Front Immunol. 2019 Jun 18;10:1345. doi: 10.3389/fimmu.2019.01345. eCollection 2019.

PMID:31316497

Abstract

T cells play significant roles during Plasmodium falciparum infections. Their regulation of the immune response in symptomatic children with malaria has been deemed necessary to prevent immune associated pathology. In this study, we phenotypically characterized the expression of T cell inhibitory(PD-1, CTLA-4) and senescent markers (CD28(-), CD57) from children with symptomatic malaria, asymptomatic malaria and healthy controls using flow cytometry. We observed increased expression of T cell exhaustion and senescence markers in the symptomatic children compared to the asymptomatic and healthy controls. T cell senescence markers were more highly expressed on CD8 T cells than on CD4 T cells. Asymptomatically infected children had comparable levels of these markers with healthy controls except for CD8+ PD-1+ T cells which were significantly elevated in the asymptomatic children. Also, using multivariate regression analysis, CTLA-4 was the only marker that could predict parasitaemia level. The results suggest that the upregulation of immune exhaustion and senescence markers during symptomatic malaria may affect the effector function of T cells leading to inefficient clearance of parasites, hence the inability to develop sterile immunity to malaria.

Keywords: CD57; CTLA-4; PD-1; Plasmodium falciparum; T-cell; exhaustion; immune senescence; malaria.

ars ago

 

JULY

55. Antitrypanosomal Effects of Zanthoxylum zanthoxyloides (Lam.) Zepern. &Amp; Timler Extracts on African Trypanosomes

Aboagye Kwarteng Dofuor  ^{1   2} , Georgina Isabella Djameh  ³ , Frederick Ayertey  ⁴ , Peter Bolah  ⁴ , Michael Amoa-Bosompem  ³ , Kwaku Kyeremeh  ⁵ , Laud Kenneth Okine  ^{1   2} , Theresa Manful Gwira  ^{1   2} , Mitsuko Ohashi  ^{3   6}

Evid Based Complement Alternat Med. 2019 Jul 4;2019:1730452. doi: 10.1155/2019/1730452. eCollection 2019.

PMID:31354849

 

Abstract

African trypanosomiasis is a disease caused by the parasitic protozoa of the Trypanosoma genus. Despite several efforts at chemotherapeutic interventions, the disease poses serious health and economic concerns to humans and livestock of many sub-Saharan African countries. Zanthoxylum zanthoxyloides (Lam.) Zepern. & Timler (Z. zanthoxyloides LZT) is a plant species of important phytochemical and pharmacological relevance in the subtropical zones of the African continent. However, the mechanisms of its antitrypanosomal effects in African trypanosomes remain to be elucidated. The aim of the study was to determine the in vitro effects and mechanisms of action of Z. zanthoxyloides LZT (root) fractions against Trypanosoma brucei. T. brucei (GUTat 3.1 strain), L. donovani (D10 strain), P. falciparum (3D 7 strain), Jurkat cells, and Chang liver cells were cultivated in vitro to the log phase in their respective media at 37°C. Crude extracts and fractions were prepared from air-dried pulverized plant material of Z. zanthoxyloides LZT (root) using the modified Kupchan method of solvent partitioning. Half-maximal inhibitory concentrations (IC₅₀) were determined through the alamar blue cell viability assay. Effects of fractions on cell death and cell cycle of T. brucei were determined using flow cytometry. Fluorescence microscopy was used to investigate the effects of fractions on the morphology and distribution of T. brucei. Antitrypanosomal compounds of fractions were characterized using high-performance liquid chromatography (HPLC) and attenuated total reflectance infrared (ATR-IR) spectroscopy. Methanol, butanol, and dichloromethane fractions were selectively active against T. brucei with respective IC₅₀ values of 3.89, 4.02, and 5.70 μg/ml. Moreover, methanol, butanol, and dichloromethane fractions significantly induced apoptosis-like cell death with remarkable alteration in the cell cycle of T. brucei. Furthermore, dichloromethane and methanol fractions altered the morphology, induced aggregation, and altered the ratio of nuclei to kinetoplasts in the parasite. The HPLC chromatograms and ATR-IR spectra of the active fractions suggested the presence of aromatic hydrocarbons with hydroxyl, carbonyl, amine, or amide functional groups. The results suggest that Z. zanthoxyloides LZT have potential chemotherapeutic effects on African trypanosomes with implications for novel therapeutic interventions in African trypanosomiasis.

56. Imbalance of Antioxidant Enzymes Activities and Trace Elements Levels in Ghanaian HIV-infected Patients

Osbourne Quaye  ¹ , Joshua Agbemefa Kuleape  ¹ , Evelyn Yayra Bonney  ² , Peter Puplampu  ³ , Emmanuel Ayitey Tagoe  ¹

PLoS One. 2019 Jul 24;14(7):e0220181. doi: 10.1371/journal.pone.0220181. eCollection 2019.

PMID:31339937

Abstract

Human immunodeficiency virus (HIV) infection and antiretroviral therapy (ART) have been associated with high oxidative stress in HIV patients. The disparity in antioxidant-oxidant levels in HIV patients favours viral replication and disease progression. This study aimed at determining the effect of ART on antioxidant enzymes activities and trace elements levels in Ghanaian HIV patients. A total of 242 participants; comprising of 105 HIV-infected patients on ART, 77 HIV-infected ART-naïve, and 60 HIV seronegative controls were recruited for the study. Whole blood was collected and used for haematological profiling, and the determination of CD4+ counts, superoxide dismutase (SOD) activity and trace element levels. Serum was used for liver function tests and the determination of glutathione reductase (GR) activity, and plasma was used to estimate reduced glutathione (GSH) levels. Low levels of haemoglobin (HB), hematocrit, mean cell volume (MCV) and mean cell hemoglobin (MCH), and trace elements were found in ART-naïve patients compared to those on ART and the seronegative controls. In the ART-naïve patients, glutathione reductase (GR) activity and reduced glutathione (GSH) level were significantly low compared to patients on ART and seronegative controls. Activity of SOD was significantly reduced in ART-naïve patients compared to those on ART and the control group, and manganese is the only trace element that showed a strong negative correlation with SOD activity and a positive and significant correlation with CD4+ count, and therefore needs to be investigated further. The study suggests that assessing antioxidant levels or enzymes activities of patients infected with HIV should be considered during therapy.

57. Contrasting Asymptomatic and Drug Resistance Gene Prevalence of Plasmodium falciparum in Ghana: Implications on Seasonal Malaria Chemoprevention

Cheikh Cambel Dieng  ¹ , Lauren Gonzalez  ² , Kareen Pestana  ² , Shittu B Dhikrullahi  ³ , Linda E Amoah  ⁴ , Yaw A Afrane  ³ , Eugenia Lo  ⁵

Genes (Basel). 2019 Jul 16;10(7). pii: E538. doi: 10.3390/genes10070538.

PMID:31315304

Abstract

Malaria is a significant public health problem in Ghana. Seasonal Malaria Chemoprevention (SMC) using a combination of sulfadoxine-pyrimethamine and amodiaquine has been implemented since 2015 in northern Ghana where malaria transmission is intense and seasonal. In this study, we estimated the prevalence of asymptomatic P. falciparum carriers in three ecological zones of Ghana, and compared the sensitivity and specificity of different molecular methods in identifying asymptomatic infections. Moreover, we examined the frequency of mutations in pfcrt, pfmdr1, pfdhfr, and pfdhps that relate to the ongoing SMC. A total of 535 asymptomatic schoolchildren were screened by microscopy and PCR (18s rRNA and TARE-2) methods. Among all samples, 28.6% were detected as positive by 18S nested PCR, whereas 19.6% were detected by microscopy. A high PCR-based asymptomatic prevalence was observed in the north (51%) compared to in the central (27.8%) and south (16.9%). The prevalence of pfdhfr-N51I/C59R/S108N/pfdhps-A437G quadruple mutant associated with sulfadoxine-pyrimethamine resistance was significantly higher in the north where SMC was implemented. Compared to 18S rRNA, TARE-2 serves as a more sensitive molecular marker for detecting submicroscopic asymptomatic infections in high and low transmission settings. These findings establish a baseline for monitoring P. falciparum prevalence and resistance in response to SMC over time.

Keywords: Plasmodium falciparum; Sulfadoxine-Pyrimethamine; TARE-2; antimalarial drug resistance; asymptomatic infections; pfdhps; phdhfr; quantitative real-time PCR.

AUGUST

58. Major Subpopulations of Plasmodium falciparum in sub-Saharan Africa

Alfred Amambua-Ngwa  ¹ , Lucas Amenga-Etego  ² , Edwin Kamau  ^{3   4} , Roberto Amato  ^{5   6} , Anita Ghansah  ⁷ , Lemu Golassa  ⁸ , Milijaona Randrianarivelojosia  ⁹ , Deus Ishengoma  ¹⁰ , Tobias Apinjoh  ¹¹ , Oumou Maïga-Ascofaré  ¹² , Ben Andagalu  ³ , William Yavo  ¹³ , Marielle Bouyou-Akotet  ¹⁴ , Oyebola Kolapo  ^{1   15} , Karim Mane  ¹ , Archibald Worwui  ¹ , David Jeffries  ¹ , Vikki Simpson  ^{4   6} , Umberto D'Alessandro  ¹ , Dominic Kwiatkowski  ^{5   6} , Abdoulaye A Djimde  ^{16   17}

Science. 2019 Aug 23;365(6455):813-816. doi: 10.1126/science.aav5427.

PMID:31439796

Abstract

Understanding genomic variation and population structure of Plasmodium falciparum across Africa is necessary to sustain progress toward malaria elimination. Genome clustering of 2263 P. falciparum isolates from 24 malaria-endemic settings in 15 African countries identified major western, central, and eastern ancestries, plus a highly divergent Ethiopian population. Ancestry aligned to these regional blocs, overlapping with both the parasite's origin and with historical human migration. The parasite populations are interbred and shared genomic haplotypes, especially across drug resistance loci, which showed the strongest recent identity-by-descent between populations. A recent signature of selection on chromosome 12 with candidate resistance loci against artemisinin derivatives was evident in Ghana and Malawi. Such selection and the emerging substructure may affect treatment-based intervention strategies against P. falciparum malaria.

59. RTS,S/AS01E Immunization Increases Antibody Responses to Vaccine-Unrelated Plasmodium Falciparum Antigens Associated With Protection Against Clinical Malaria in African Children: A Case-Control Study

Carlota Dobaño  ^{1   2} , Itziar Ubillos  ³ , Chenjerai Jairoce  ⁴ , Ben Gyan  ^{5   6} , Marta Vidal  ³ , Alfons Jiménez  ^{3   7} , Rebeca Santano  ³ , David Dosoo  ⁶ , Augusto J Nhabomba  ⁴ , Aintzane Ayestaran  ³ , Ruth Aguilar  ³ , Nana Aba Williams  ³ , Núria Díez-Padrisa  ³ , David Lanar  ⁸ , Virander Chauhan  ⁹ , Chetan Chitnis  ^{9   10} , Sheetij Dutta  ⁸ , Deepak Gaur  ^{9   11} , Evelina Angov  ⁸ , Kwaku Poku Asante  ⁶ , Seth Owusu-Agyei  ^{6   12} , Clarissa Valim  ^{13   14} , Benoit Gamain  ¹⁵ , Ross L Coppel  ¹⁶ , David Cavanagh  ¹⁷ , James G Beeson  ¹⁸ , Joseph J Campo  ^{3   4} , Gemma Moncunill  ^{19   20}

BMC Med. 2019 Aug 14;17(1):157. doi: 10.1186/s12916-019-1378-6.

PMID:31409398

Abstract

Background: Vaccination and naturally acquired immunity against microbial pathogens may have complex interactions that influence disease outcomes. To date, only vaccine-specific immune responses have routinely been investigated in malaria vaccine trials conducted in endemic areas. We hypothesized that RTS,S/A01E immunization affects acquisition of antibodies to Plasmodium falciparum antigens not included in the vaccine and that such responses have an impact on overall malaria protective immunity.

Methods: We evaluated IgM and IgG responses to 38 P. falciparum proteins putatively involved in naturally acquired immunity to malaria in 195 young children participating in a case-control study nested within the African phase 3 clinical trial of RTS,S/AS01E (MAL055 NCT00866619) in two sites of different transmission intensity (Kintampo high and Manhiça moderate/low). We measured antibody levels by quantitative suspension array technology and applied regression models, multimarker analysis, and machine learning techniques to analyze factors affecting their levels and correlates of protection.

Results: RTS,S/AS01E immunization decreased antibody responses to parasite antigens considered as markers of exposure (MSP1₄₂, AMA1) and levels correlated with risk of clinical malaria over 1-year follow-up. In addition, we show for the first time that RTS,S vaccination increased IgG levels to a specific group of pre-erythrocytic and blood-stage antigens (MSP5, MSP1 block 2, RH4.2, EBA140, and SSP2/TRAP) which levels correlated with protection against clinical malaria (odds ratio [95% confidence interval] 0.53 [0.3-0.93], p = 0.03, for MSP1; 0.52 [0.26-0.98], p = 0.05, for SSP2) in multivariable logistic regression analyses.

Conclusions: Increased antibody responses to specific P. falciparum antigens in subjects immunized with this partially efficacious vaccine upon natural infection may contribute to overall protective immunity against malaria. Inclusion of such antigens in multivalent constructs could result in more efficacious second-generation multistage vaccines.

Keywords: Antibody; Blood-stage antigens; Malaria; Maternal antibodies; Naturally acquired immunity; Plasmodium falciparum; Pre-erythrocytic antigens; Protection; RTS,S; Vaccine.

, 13 (8), e0007115

2019 Aug 9eCollection Aug 2019

60.  Progress Towards Lymphatic Filariasis Elimination in Ghana From 2000-2016: Analysis of Microfilaria Prevalence Data From 430 Communities

Nana Kwadwo Biritwum  ¹ , Kwadwo K Frempong  ^{2   3} , Suzanne Verver  ³ , Samuel Odoom  ¹ , Bright Alomatu  ¹ , Odame Asiedu  ¹ , Periklis Kontoroupis  ³ , Abednego Yeboah  ¹ , Edward Tei Hervie  ¹ , Benjamin Marfo  ¹ , Daniel A Boakye  ^{2   4} , Sake J de Vlas  ³ , John O Gyapong  ^{5   6} , Wilma A Stolk  ³

• DOI: 10.1371/journal.pntd.0007115
• PLoS Negl Trop Dis. 2019 Aug 9;13(8):e0007115. doi: 10.1371/journal.pntd.0007115.

Abstract

Background: Ghana started its national programme to eliminate lymphatic filariasis (LF) in 2000, with mass drug administration (MDA) with ivermectin and albendazole as main strategy. We review the progress towards elimination that was made by 2016 for all endemic districts of Ghana and analyze microfilaria (mf) prevalence from sentinel and spot-check sites in endemic districts.

Methods: We reviewed district level data on the history of MDA and outcomes of transmission assessment surveys (TAS). We further collated and analyzed mf prevalence data from sentinel and spot-check sites.

Results: MDA was initiated in 2001-2006 in all 98 endemic districts; by the end of 2016, 81 had stopped MDA after passing TAS and after an average of 11 rounds of treatment (range 8-14 rounds). The median reported coverage for the communities was 77-80%. Mf prevalence survey data were available for 430 communities from 78/98 endemic districts. Baseline mf prevalence data were available for 53 communities, with an average mf prevalence of 8.7% (0-45.7%). Repeated measurements were available for 78 communities, showing a steep decrease in mean mf prevalence in the first few years of MDA, followed by a gradual further decline. In the 2013 and 2014 surveys, 7 and 10 communities respectively were identified with mf prevalence still above 1% (maximum 5.6%). Fifteen of the communities above threshold are all within districts where MDA was still ongoing by 2016.

Conclusions: The MDA programme of the Ghana Health Services has reduced mf prevalence in sentinel sites below the 1% threshold in 81/98 endemic districts in Ghana, yet 15 communities within 13 districts (MDA ongoing by 2016) had higher prevalence than this threshold during the surveys in 2013 and 2014. These districts may need to intensify interventions to achieve the WHO 2020 target.

 

61.  Diversity and Immune Responses Against Plasmodium Falciparum Gametocytes in Non-Febrile School Children Living in Southern Ghana

Linda E Amoah  ^{1   2} , Hamza B Abagna  ^{3   4} , Ruth Ayanful-Torgby  ³ , Samuel O Blankson  ⁴ , Nii A Aryee  ⁴

Malar J. 2019 Aug 1;18(1):265. doi: 10.1186/s12936-019-2895-7.

 

Abstract

Background: Natural exposure to gametocytes can result in the development of immunity against the gametocyte by the host as well as genetic diversity in the gametocyte. This study evaluated the quantity and quality of natural immune responses against a gametocyte antigen, Pfs230 as well as the prevalence and diversity of gametocytes circulating in children living in two communities in southern Ghana.

Methods: Whole blood (2.5 ml) was collected from 137 non-febrile school children aged between 6 and 12 years old quarterly for a 6-month period. A drop of blood was used to prepare thick and thin blood films for parasite prevalence and density estimation. Subsequently, stored plasma samples were used in ELISAs assays to measure antibody responses and avidity against Pfs230. RNA was extraction from Trizol preserved packed cells and subsequently converted to complementary DNA (cDNA) which was used for reverse transcriptase PCR (RT-PCR) to determine gametocytes prevalence and diversity.

Results: Gametocyte carriage in the peak season (July) determined by Pfg377 RT-PCR was 49.2% in Obom and 22.2% in Abura, and was higher than that determined by microscopy. Gametocyte diversity was low and predominated by the same allele at both sites. The relative avidity index for antibodies measured in Abura was higher than that recorded in Obom at all time points although Pfs230 IgG concentrations were significantly high (P < 0.0001) in Obom than in Abura at all time points. The IgG responses in Obom were significantly higher than that in Abura during the peak season.

Conclusion: Naturally induced antibody responses against Pfs230 in children living in both high perennial and low seasonal malaria transmission settings reduced significantly in moving from the peak to the off-peak season. The relative avidity of antibodies against Pfs230 in Abura was significantly higher than those measured in Obom, despite having lower IgG levels. Very limited diversity was identified in the gametocytes circulating in both Obom and Abura.

Keywords: Gametocyte; IgG responses; Malaria transmission; Pfs230; Relative avidity.

 

SEPTEMBER

62.  Extent of Inappropriate Prescription of Artemisinin and Anti-Malarial Injections to Febrile Outpatients, a Cross-Sectional Analytic Survey in the Greater Accra Region, Ghana

Harriet Affran Bonful  ^{1   2} , Adolf Kofi Awua  ³ , Martin Adjuik  ⁴ , Doris Tsekpetse  ⁵ , Richard Mawuko Kofi Adanu  ⁶ , Pricillia Awo Nortey  ⁷ , Augustine Ankomah  ^{6   8} , Kwadwo Ansah Koram  ⁹

Malar J. 2019 Sep 27;18(1):331. doi: 10.1186/s12936-019-2967-8.

 

Abstract

Background: Febrile children seen in malaria hypo-endemic settings, such as the Greater Accra region (GAR) of Ghana are more likely to be suffering from a non-malarial febrile illness compared to those seen in hyper-endemic settings. The need for prescribers to rely on malaria test results to guide treatment practices in the GAR is even greater. This study was designed to investigate the factors associated with inappropriate artemisinin-based combination therapy (ACT) prescription.

Methods: A survey was conducted in six health facilities in the region in 2015. Treatment practices for febrile outpatient department (OPD) patients were obtained from their records. Prescribers were interviewed and availability of malaria commodities were assessed. The primary outcome was the proportion of patients prescribed ACT inappropriately. Independent variables included patient age and access to care, prescriber factors (professional category, work experience, access to guidelines, exposure to training). Data were analysed using Stata at 95% CI (α-value of 0.05). Frequencies and means were used to describe the characteristics of patients and prescribers. To identify the predictors of inappropriate ACT prescription, regression analyses were performed accounting for clustering.

Results: Overall, 2519 febrile OPD records were analysed; 45.6% (n = 1149) were younger than 5 years. Only 40.0% of patients were tested. The proportion of patients who were prescribed ACT inappropriately was 76.4% (n = 791 of 1036). Of these 791 patients, 141 (17.8%) were prescribed anti-malarial injections. Patients seen in facilities with rapid diagnostic tests (RDT) in stock were less likely to be prescribed ACT inappropriately, (AOR: 0.04, 95% CI 0.01-0.14, p < 0.001) compared to those seen in facilities with RDT stock-outs. Prescribers who had been trained on malaria case management within the past year were 4 times more likely to prescribe ACT inappropriately compared to those who had not been trained (AOR: 4.1; 95% CI (1.5-11.6); p < 0.01). Patients seen by prescribers who had been supervised were 8 times more likely to be prescribed ACT inappropriately.

Conclusion: Inappropriate ACT prescription to OPD febrile cases was high. Training and supervision of health workers appears not to be yielding the desired outcomes. Further research is needed to understand this observation.

63.  Targeted Next Generation Sequencing for Malaria Research in Africa: Current Status and Outlook

Anita Ghansah  ¹ , Edwin Kamau  ^{2   3} , Alfred Amambua-Ngwa  ⁴ , Deus S Ishengoma  ⁵ , Oumou Maiga-Ascofare  ⁶ , Lucas Amenga-Etego  ⁷ , Awa Deme  ⁸ , William Yavo  ^{9   10} , Milijaona Randrianarivelojosia  ¹¹ , Plasmodium Diversity Network Africa, Lynette Isabella Ochola-Oyier  ¹² , Gideon Kofi Helegbe  ¹³ , Jeffery Bailey  ¹⁴ , Michael Alifrangis  ¹⁵ , Abdoulaye Djimde  ^{16   17}

Malar J. 2019 Sep 23;18(1):324. doi: 10.1186/s12936-019-2944-2.

 

Abstract

Targeted Next Generation Sequencing (TNGS) is an efficient and economical Next Generation Sequencing (NGS) platform and the preferred choice when specific genomic regions are of interest. So far, only institutions located in middle and high-income countries have developed and implemented the technology, however, the efficiency and cost savings, as opposed to more traditional sequencing methodologies (e.g. Sanger sequencing) make the approach potentially well suited for resource-constrained regions as well. In April 2018, scientists from the Plasmodium Diversity Network Africa (PDNA) and collaborators met during the 7th Pan African Multilateral Initiative of Malaria (MIM) conference held in Dakar, Senegal to explore the feasibility of applying TNGS to genetic studies and malaria surveillance in Africa. The group of scientists reviewed the current experience with TNGS platforms in sub-Saharan Africa (SSA) and identified potential roles the technology might play to accelerate malaria research, scientific discoveries and improved public health in SSA. Research funding, infrastructure and human resources were highlighted as challenges that will have to be mitigated to enable African scientists to drive the implementation of TNGS in SSA. Current roles of important stakeholders and strategies to strengthen existing networks to effectively harness this powerful technology for malaria research of public health importance were discussed.

64.  Completeness of Obstetric Referral Letters/Notes From Subdistrict to District Level in Three Rural Districts in Greater Accra Region of Ghana: An Implementation Research Using Mixed Methods

Mary Amoakoh-Coleman  ^{1   2} , Evelyn Ansah  ³ , Kerstin Klipstein-Grobusch  ^{2   4} , Daniel Arhinful  ⁵

BMJ Open. 2019 Sep 13;9(9):e029785. doi: 10.1136/bmjopen-2019-029785.

 

Abstract

Objective: To assess the completeness of obstetric referral letters/notes at the district level of healthcare.

Design: An implementation research within three districts in Greater Accra region using mixed methods. During baseline and intervention phases, referral processes for all obstetric referrals from lower level facilities seen at the district hospitals were documented including indications for referrals, availability and completeness of referral notes/forms. An assessment of before and after intervention availability and completeness of referral forms was carried out. Focus group discussions, non-participant observations and in-depth interviews with health workers and pregnant women were conducted for qualitative data.

Setting: Three (3) districts in the Greater Accra region of Ghana.

Participants: Pregnant women referred from lower levels of care to and seen at the district hospital, health workers within the three districts and pregnant women attending antenatal clinic in the district and their family members or spouses.

Intervention: An enhanced interfacility referral communication system consisting of training, provision of communication tools for facilities, formation of hospital referral teams and strengthening feedback mechanisms.

Outcome: Completeness of obstetric referral letters/notes.

Results: Proportion of obstetric referrals with referral notes improved from 27.2% to 44.3% from the baseline to intervention period. Mean completeness (95% CI) of all forms was 71.3% (64.1% to 78.5%) for the study period, improving from 70.7% (60.4% to 80.9%) to 71.9% (61.1% to 82.7%) from baseline to intervention periods. Health workers reported they do not always provide referral notes and that most referral notes are not completely filled due to various reasons.

Conclusions: Most obstetric referrals did not have referral notes. The few notes provided were not completely filled. Interventions such as training of health workers, regular review of referral processes and use of electronic records can help improve both the provision of and completeness of the referral notes.

65.  Levels of Serum Eosinophil Cationic Protein Are Associated With Hookworm Infection and Intensity in Endemic Communities in Ghana

Benjamin Amoani  ^{1   2   3} , Bright Adu  ² , Margaret T Frempong  ³ , Tracy Sarkodie-Addo  ² , Samuel Victor Nuvor  ⁴ , Michael D Wilson  ⁵ , Ben Gyan  ²

PLoS One. 2019 Sep 12;14(9):e0222382. doi: 10.1371/journal.pone.0222382. eCollection 2019.

 

Abstract

Background: The eosinophil cationic protein (ECP) is a cytotoxic protein mainly secreted by eosinophils granulocytes and plays a role in host defense against parasitic infections. Infection with Necator americanus (hookworm) is traditionally diagnosed by the Kato-Katz method which is inherently tedious, subjective and known to underestimate infection intensity. This study aimed to assess levels of serum ECP in relation to hookworm infection intensity.

Methods: Stool samples from 984 (aged 4 to 80 years) participants in a cross-sectional study conducted in the Kintampo North Municipality of Ghana were examined using the Kato-Katz and formol-ether concentration methods. Serum ECP levels were measured by ECP assay kit and compared between 40 individuals infected with hookworm only, 63 with hookworm- Plasmodium falciparum co-infection, 59 with P. falciparum infection and 36 with no infection.

Results: Hookworm infection prevalence was 18.1% (178/984). ECP levels were significantly higher in individuals infected with hookworm only (β = 2.96, 95%CI = 2.69, 3.23, p<0.001) or co-infected with P. falciparum (β = 3.15, 95%CI = 2.91, 3.39, p<0.001) compared to the negative control. Levels of ECP were similar between those with only P. falciparum infection and the uninfected control (p>0.05). Increased hookworm intensity was associated with a significant increase in ECP level (β = 4.45, 95%CI = 2.25, 9.11, rs = 0.193, n = 103, p<0.01). ECP threshold of 84.98ng/ml was associated with a positive predictive value (PPV) of 98% (95% CI = 92, 100), and negative predictive value (NPV) of 76% (95% CI = 62, 87) in classifying hookworm infection status with an AUROC of 96.3%.

Conclusion: Serum ECP level may be a good biomarker of hookworm infection and intensity and warrant further investigations to help improve current hookworm diagnosis.

66.  To Keep or Not to Keep? Decision Making in Adolescent Pregnancies in Jamestown, Ghana

Luchuo Engelbert Bain  ^{1   2} , Marjolein B M Zweekhorst  ¹ , Mary Amoakoh-Coleman  ³ , Seda Muftugil-Yalcin  ¹ , Abejirinde Ibukun-Oluwa Omolade  ⁴ , Renaud Becquet  ² , Tjard de Cock Buning  ¹

PLoS One. 2019 Sep 4;14(9):e0221789. doi: 10.1371/journal.pone.0221789. eCollection 2019.

Abstract

Background: Jamestown, an urban coastal slum in Accra, Ghana, has one of the highest adolescent pregnancy rates in the country. We sought to understand the decision (to keep or terminate) factors and experiences surrounding adolescent pregnancies.

Methods: Thirty semi-structured indepth interviews were carried out among adolescents (aged 13-19 years) who had been pregnant at least once. Half of these were adolescent mothers and the other half had at least one past experience of induced abortion. A pretested and validated questionnaire to assess the awareness and use of contraception in adolescent participants was also administered. To aid social contextualization, semi-structured in depth interviews were carried out among 23 purposively selected stakeholders.

Results: The main role players in decision making included family, friends, school teachers and the partner, with pregnant adolescents playing the most prominent role. Adolescents showed a high degree of certainty in deciding to either abort or carry pregnancies to term. Interestingly, religious considerations were rarely taken into account. Although almost all adolescents (96.1%) were aware of contraception, none was using any prior to getting pregnant. Of the 15 adolescents who had had abortion experiences, 13 (87.0%) were carried out under unsafe circumstances. The main barriers to accessing safe abortion services included poor awareness of the fairly liberal nature of the Ghanaian abortion law, stigma, high cost and non-harmonization of safe abortion service fees, negative abortion experiences (death and bleeding), and distrust in the health care providers. Adolescents who chose to continue their pregnancies to term were motivated by personal and sociocultural factors.

Conclusion: Decision-making in adolescent pregnancies is influenced by multiple external factors, many of which are modifiable. Despite legal access to services, options for the safe termination of pregnancy or its prevention are not predominantly taken, resulting in a high number of negative experiences and outcomes. Including safe abortion care within the sexual and reproductive health package, could diminish barriers to safe abortion services. Given the vulnerability of the Jamestown setting, a comprehensive sexual education package that addresses the main decision factors is recommended. Interventions aiming to reduce adolescent pregnancy rates should also recognize that adolescent pregnancies are culturally acceptable in some settings, and under certain circumstances, are desired by the adolescents themselves.

67. Re: Musings on malaria morbidity and mortality after the new Mosquirix_®

Asante KP, Malm K, Darko DM, Koram KA.

Ghana Med J. 2019 Sep;53(3):252-253. doi: 10.4314/gmj.v53i3.10.

No abstract available.

 

OCTOBER

68.  Antimicrobial Resistance (AMR) and Molecular Characterization of Neisseria Gonorrhoeae in Ghana, 2012-2015

Naiki Attram  ^{1   2} , Bright Agbodzi  ^{1   2} , Helena Dela  ^{1   2} , Eric Behene  ^{1   2} , Edward O Nyarko  ³ , Nicholas N A Kyei  ³ , John A Larbi  ⁴ , Bernard W L Lawson  ⁴ , Kennedy K Addo  ² , Mercy J Newman  ⁵ , Christopher A Duplessis  ¹ , Nehkonti Adams  ¹ , Magnus Unemo  ⁶ , Andrew G Letizia  ¹

PLoS One. 2019 Oct 10;14(10):e0223598. doi: 10.1371/journal.pone.0223598. eCollection 2019.

Abstract

Neisseria gonorrhoeae antimicrobial resistance (AMR) surveillance is essential for tracking the emergence and spread of AMR strains in local, national and international populations. This is crucial for developing or refining treatment guidelines. N. gonorrhoeae multiantigen sequence typing (NG-MAST) is beneficial for describing the molecular epidemiology of gonococci at national and international levels. Elucidation of AMR determinants to β-lactam drugs, is a means of monitoring the development of resistance. In Ghana, little is known about the current gonococcal AMR prevalence and no characterization of gonococcal isolates has been previously performed. In this study, gonococcal isolates (n = 44) collected from five health facilities in Ghana from 2012 to 2015, were examined using AMR testing, NG-MAST and sequencing of penA. High rates of resistance were identified to tetracycline (100%), benzylpenicillin (90.9%), and ciprofloxacin (81.8%). One isolate had a high cefixime MIC (0.75 μg/ml). Twenty-eight NG-MAST sequence types (STs) were identified, seventeen of which were novel. The isolate with the high cefixime MIC contained a mosaic penA-34 allele and belonged to NG-MAST ST1407, an internationally spreading multidrug-resistant clone that has accounted for most cefixime resistance in many countries. In conclusion, AMR testing, NG-MAST, and sequencing of the AMR determinant penA, revealed high rates of resistance to tetracycline, benzylpenicillin, and ciprofloxacin; as well as a highly diverse population of N. gonorrhoeae in Ghana. It is imperative to continue with enhanced AMR surveillance and to understand the molecular epidemiology of gonococcal strains circulating in Ghana and other African countries.

 

NOVEMEBR

69.  Computational/in Silico Methods in Drug Target and Lead Prediction

Francis E Agamah  ¹ , Gaston K Mazandu  ^{1   2} , Radia Hassan  ¹ , Christian D Bope  ^{1   3} , Nicholas E Thomford  ^{1   4} , Anita Ghansah  ⁵ , Emile R Chimusa  ¹

Brief Bioinform. 2019 Nov 10. pii: bbz103. doi: 10.1093/bib/bbz103. [Epub ahead of print]

 

Abstract

Drug-like compounds are most of the time denied approval and use owing to the unexpected clinical side effects and cross-reactivity observed during clinical trials. These unexpected outcomes resulting in significant increase in attrition rate centralizes on the selected drug targets. These targets may be disease candidate proteins or genes, biological pathways, disease-associated microRNAs, disease-related biomarkers, abnormal molecular phenotypes, crucial nodes of biological network or molecular functions. This is generally linked to several factors, including incomplete knowledge on the drug targets and unpredicted pharmacokinetic expressions upon target interaction or off-target effects. A method used to identify targets, especially for polygenic diseases, is essential and constitutes a major bottleneck in drug development with the fundamental stage being the identification and validation of drug targets of interest for further downstream processes. Thus, various computational methods have been developed to complement experimental approaches in drug discovery. Here, we present an overview of various computational methods and tools applied in predicting or validating drug targets and drug-like molecules. We provide an overview on their advantages and compare these methods to identify effective methods which likely lead to optimal results. We also explore major sources of drug failure considering the challenges and opportunities involved. This review might guide researchers on selecting the most efficient approach or technique during the computational drug discovery process.

 

DECEMBER

70.  Molecular Analysis of Mycobacterium tuberculosis Isolated in the North Central Zone of Nigeria

Benjamin David Thumamo Pokam  ^{1   2} , Dorothy Yeboah-Manu  ² , Lovett Lawson  ³ , Prisca Wabo Guemdjom  ⁴ , Ruth Okonu  ² , Laura Madukaji  ³ , Nchawa Yangkam Yhiler  ^{1   5} , Anne Ebri Asuquo  ⁶

J Epidemiol Glob Health. 2019 Dec;9(4):259-265. doi: 10.2991/jegh.k.191015.001.

 

Abstract

Tuberculosis (TB) incidence in Nigeria is high, with a significant burden of TB/Human Immunodeficiency Virus (HIV). Genotyping and drug susceptibility of Mycobacterium tuberculosis Complex (MTBC) are important in order to improve the control of the disease. This study sought to determine drug susceptibility and genetic diversity of MTBC in the country. The sputum samples of 202 patients [133 (65.8%) males/69 (34.2%) females] were collected in the North Central zone of Nigeria and cultured using Lowenstein-Jensen medium. Immunochromatography for the primary identification and Drug Susceptibility Testing (DST) by proportion method, as well as IS6110 typing, regions of difference 1, 4, 9, 12, 702, and 711, and spoligotyping were carried out on the isolates. Following the DST on 202 isolates, 51 (25.2%) showed resistance to at least one drug. Multidrug resistance was observed in 29/202 (14.4%) cases. HIV positivity [37/202 (18.3%) patients] was associated with rifampicin 9/37 (24.3%) resistance (p = 0.012) as well as gender (p = 0.009). Of the 202 isolates, 150 (74.3%) were identified as the Cameroon sublineage, followed by the UgandaI, Haarlem, and West Africa 1 with 18 (8.9%), 10 (5%), and 6 (3%), respectively. The LAM10_CAM was the most prevalent genetic family [128/202 (63.4%)], with the shared international type 61 [111 (55%) isolates] the largest cluster. Gender (p = 0.038) and age (p = 0.015) had significant associations with the LAM10_CAM family but neither with HIV (p = 0.479) nor drug resistance. Rifampicin resistance in TB/HIV coinfected patient is a major concern in the study area. The Mycobacterium africanum lineage showed a marked decrease, and the need to educate females most at risk of TB/HIV coinfection is advocated.

71.  The Dual Specificity Kinase DYRK1A Modulates the Levels of Cyclin L2 to Control HIV Replication in Macrophages

Javan K Kisaka  ¹ , Lee Ratner  ^{1   1} , George B Kyei  ^{2   1   3}

J Virol. 2019 Dec 18. pii: JVI.01583-19. doi: 10.1128/JVI.01583-19. [Epub ahead of print]

 

Abstract

HIV replication in macrophages contributes to the latent viral reservoirs which is considered the main barrier to HIV eradication. Few cellular factors that facilitate HIV replication in latently infected cells are known. We previously identified cyclin L2 as a critical factor required by HIV-1, and found that depletion of cyclin L2 attenuates HIV-1 replication in macrophages. Here we demonstrate that cyclin L2 promotes HIV-1 replication through interactions with the dual specificity tyrosine phosphorylation-regulated kinase 1A (DYRK1A). Cyclin L2 and DYRK1A were colocalized in the nucleus and were found together in immunoprecipitation experiments. Knockdown or inhibition of DYRK1A increased HIV-1 replication in macrophages while depletion of cyclin L2 decreased HIV-1 replication. Furthermore, depletion of DYRK1A increased expression levels of cyclin L2. DYRK1A is a proline directed kinase that phosphorylates cyclin L2 at serine residues. Mutants of cyclin L2 at serine residues preceding proline significantly stabilized cyclin L2 and increased HIV-1 replication in macrophages. Thus, we propose that DYRK1A controls cyclin L2 expression leading to restriction of HIV replication in macrophages.Importance HIV continues to be a major public health problem worldwide with over 36 million people living with the virus. Although anti-retroviral therapy (ART) can control the virus, it does not provide cure. The virus hides in the genome of long-lived cells like resting CD4+ T cells and differentiated macrophages. To get a cure for HIV, it is important to identify and characterize the cellular factors that control HIV multiplication in these reservoir cells. Previous work showed that cyclin L2 is required for HIV replication in macrophages. However, how cyclin L2 is regulated in macrophages is unknown. Here, we show that the protein DYRK1A interacts with and phosphorylates cyclin L2. Phosphorylation makes cyclin L2 amenable to cellular degradation, leading to restriction of HIV replication in macrophages.

72.  A Praziquantel Treatment Study of Immune and Transcriptome Profiles in Schistosoma Haematobium-Infected Gabonese Schoolchildren

Lucja A Labuda  ^{1   2   3} , Ayola A Adegnika  ^{1   2   3} , Bruce A Rosa  ⁴ , John Martin  ⁴ , Ulysse Ateba-Ngoa  ^{1   2   3} , Abena Serwaa Amoah  ^{1   5} , Honorine Mbenkep Lima  ^{1   2   3} , Lynn Meurs  ⁶ , Moustapha Mbow  ⁷ , Mikhael D Manurung  ¹ , Jeannot F Zinsou  ² , Hermelijn H Smits  ¹ , Peter G Kremsner  ^{2   3} , Makedonka Mitreva  ^{4   8} , Maria Yazdanbakhsh  ¹

J Infect Dis. 2019 Dec 17. pii: jiz641. doi: 10.1093/infdis/jiz641. [Epub ahead of print]

 

Abstract

Schistosoma infection has been associated with altered immune function, including hyporesponsiveness. S. haematobium-infected schoolchildren were studied before and after praziquantel treatment and compared to uninfected controls. Cellular responses were characterised by cytokine production and flow cytometry, and in a subset of children RNA-Seq transcriptome profiling performed. Removal of S. haematobium infection resulted in increased schistosome-specific cytokine responses which were negatively associated with CD4+CD25+FOXP3+ T cells and accompanied by increased frequency of effector memory T cells. Innate responses to TLR ligation decreased with treatment and showed positive association with CD4+CD25+FOXP3+ T cells. At the transcriptome level, schistosome infection was associated with enrichment in cell adhesion, while parasite removal with a more quiescent profile. Further analysis indicated alteration in cellular energy metabolism to be associated with S. haematobium infection and that EGR2 and EGR3, transcription factors which negatively regulate T cell activation, may play a role in adaptive immune hyporesponsiveness.

73.  High Uptake of Intermittent Preventive Treatment of Malaria in Pregnancy Is Associated With Improved Birth Weight Among Pregnant Women in Ghana

Isabella Quakyi  ^{1   2} , Bernard Tornyigah  ^{1   3} , Pascal Houze  ^{4   5   6} , Kwadwo A Kusi  ³ , Nathaniel Coleman  ² , Guillaume Escriou  ¹ , Amos Laar  ² , Michel Cot  ¹ , Julius Fobil  ² , Gloria Quansah Asare  ² , Philippe Deloron  ¹ , Abraham K Anang  ⁶ , Gilles Cottrell  ¹ , Michael F Ofori  ³ , Nicaise Tuikue Ndam  ^{7   8}

Sci Rep. 2019 Dec 13;9(1):19034. doi: 10.1038/s41598-019-55046-5.

 

Abstract

Despite the clinically proven advantages of intermittent preventive treatment of malaria in pregnancy (IPTp) with sulfadoxine-pyrimethamine (SP), utilisation has been low in many African countries. To increase uptake and achieve the desired effect, the World Health Organization revised the policy to a monthly administration. Assessing the coverage and impact of the revised policy on pregnancy and neonatal outcomes is, therefore, a necessity. A 2-parallel cross-sectional hospital-based study was carried out among pregnant women attending first antenatal care (ANC) and delivery. Maternal and cord blood samples were assayed for malaria parasites by quantitative PCR targeting both the 18S rDNA and the acidic terminal segment of Plasmodium falciparum var genes, and plasma SP levels were measured by liquid chromatography coupled to tandem mass spectrometry. Parasite prevalence was similar between the two study sites but decreased significantly between the first ANC (9% or 43%) and delivery (4% or 11%) based on the qPCR target. At delivery, 64.5% of women received ≥3 IPTp-SP dose, 15.5% received 2 doses and 6% had 1 dose. Taking ≥3 IPTp-SP doses was associated with an average birth weight increase of more than 0.165 kg. IPTp-SP uptake was associated with plasma SP level at delivery (OR = 32.3, p ≤ 0.005, 95% CI (13.3;78.4) for those that reported ≥3 IPTp-SP doses) while the same trend of improved birth weight was observed with high plasma SP levels. The new IPTp policy is well implemented and well utilised by women in the sites considered in this study and translates to the improved birth weight observed. This study confirms the interest and the clinical benefit expected from this policy change.

74.  Challenges and Responses to Infant and Young Child Feeding in Rural Rwanda: A Qualitative Study

Jeanine Ahishakiye  ^{1   2} , Laura Bouwman  ³ , Inge D Brouwer  ⁴ , Eric Matsiko  ^{4   5} , Margaret Armar-Klemesu  ⁶ , Maria Koelen  ³

J Health Popul Nutr. 2019 Dec 12;38(1):43. doi: 10.1186/s41043-019-0207-z.

 

Abstract

Background: Despite different interventions to improve child nutrition conditions, chronic malnutrition is still a public health concern in Rwanda, with a high stunting prevalence of 38% among under 5-year-olds children. In Rwanda, only 18% of children aged 6-23 months are fed in accordance with the recommendations for infant and young child feeding practices. The aim of this study was to explore challenges to infant and young child feeding practices and the responses applied to overcome these challenges in Muhanga District, Southern province of Rwanda.

Methods: Sixteen (16) focus group discussions were held with mothers, fathers, grandmothers, and community health workers from 4 rural sectors of Muhanga District. The discussions were recorded, transcribed verbatim, and thematically analyzed using qualitative data analysis software, Atlas.ti.

Results: Two main themes emerged from the data. Firstly, there was a discourse on optimal infant and young child feeding (IYCF) practices that reflects the knowledge and efforts to align with early initiation of breastfeeding, exclusive breastfeeding for the first 6 months, as well as initiation of complementary foods at 6 months recommendations. Secondly, challenging situations against optimal practices and coping responses applied were presented in a discourse on struggling with everyday reality. The challenging situations that emerged as impeding appropriate IYCF practices included perceived lack of breast milk, infant cues, women's heavy workload, partner relations and living in poverty. Family and social support from community health workers and health facility staff, financial support through casual labor, and mothers saving and lending groups, as well as kitchen gardens, were used to cope with challenges.

Conclusion: Factors influencing IYCF practices are multifaceted. Hence, intervention strategies to improve child nutrition should acknowledge the socially embedded nature of IYCF and address economic and social environmental constraints and opportunities, in addition and above knowledge only.

75.  Understanding the Gap Between Access and Use: A Qualitative Study on Barriers and Facilitators to Insecticide-Treated Net Use in Ghana

Collins Stephen Ahorlu  ¹ , Philip Adongo  ² , Hannah Koenker  ³ , Sixte Zigirumugabe  ⁴ , Solomon Sika-Bright  ⁵ , Eric Koka  ⁵ , Philip Teg-Nefaah Tabong  ² , Danielle Piccinini  ³ , Sylvester Segbaya  ⁶ , Bolanle Olapeju  ³ , April Monroe  ^{7   8   9}

Malar J. 2019 Dec 12;18(1):417. doi: 10.1186/s12936-019-3051-0.

 

Abstract

Background: Mass and continuous distribution channels have significantly increased access to insecticide-treated nets (ITNs) in Ghana since 2000. Despite these gains, a large gap remains between ITN access and use.

Methods: A qualitative research study was carried out to explore the individual and contextual factors influencing ITN use among those with access in three sites in Ghana. Eighteen focus group discussions, and free listing and ranking activities were carried out with 174 participants; seven of those participants were selected for in-depth case study. Focus group discussions and case study interviews were audio-recorded, transcribed verbatim, and analysed thematically.

Results: ITN use, as described by study participants, was not binary; it varied throughout the night, across seasons, and over time. Heat was the most commonly cited barrier to consistent ITN use and contributed to low reported ITN use during the dry season. Barriers to ITN use throughout the year included skin irritation; lack of airflow in the sleeping space; and, in some cases, a lack of information on the connection between the use of ITNs and malaria prevention. Falling ill or losing a loved one to malaria was the most powerful motivator for consistent ITN use. Participants also discussed developing a habit of ITN use and the economic benefit of prevention over treatment as facilitating factors. Participants reported gender differences in ITN use, noting that men were more likely than women and children to stay outdoors late at night and more likely to sleep outdoors without an ITN.

Conclusion: The study results suggest the greatest gains in ITN use among those with access could be made by promoting consistent use throughout the year among occasional and seasonal users. Opportunities for improving communication messages, such as increasing the time ITNs are aired before first use, as well as structural approaches to enhance the usability of ITNs in challenging contexts, such as promoting solutions for outdoor ITN use, were identified from this work. The information from this study can be used to inform social and behaviour change messaging and innovative approaches to closing the ITN use gap in Ghana.

76.  Prevalence of Asymptomatic Malaria Parasitaemia Following Mass Testing and Treatment in Pakro Sub-District of Ghana

Ignatius Cheng Ndong  ^{1   2} , Daniel Okyere  ³ , Juliana Yartey Enos  ³ , Benedicta A Mensah  ³ , Alexander Nyarko  ³ , Benjamin Abuaku  ³ , Alfred Amambua-Ngwa  ⁴ , Corinne Simone C Merle  ⁵ , Kwadwo Ansah Koram  ³ , Collins Stephen Ahorlu  ³

BMC Public Health. 2019 Dec 3;19(1):1622. doi: 10.1186/s12889-019-7986-4.

 

Abstract

Background: Global efforts to scale-up malaria control interventions are gaining steam. These include the use of Long-Lasting Insecticide Nets, Indoor Residual Spraying, Intermittent Preventive Treatment and Test, Treat and Track. Despite these, the drive for malaria elimination is far from being realistic in endemic communities in Africa. This is partly due to the fact that asymptomatic parasite carriage, not specifically targeted by most interventions, remains the bedrock that fuels transmission. This has led to mass testing, treatment and tracking (MTTT) as an alternative strategy to target asymptomatic individuals. We report the impact of MTTT on the prevalence of asymptomatic malaria parasitaemia over a one-year period in Ghana, hypothesizing that implementing MTTT could reduce the rate of asymptomatic parasitaemia.

Methods: A population of about 5000 individuals in seven communities in the Pakro sub-district of Ghana participated in this study. A register was developed for each community following a census. MTTT engaged trained community-based health volunteers who conducted house-to-house testing using RDTs every 4 months and treated positive cases with Artemisinin-based Combination Therapy. Between interventions, community-based management of malaria was implemented for symptomatic cases.

Results: MTTT Coverage was 98.8% in July 2017 and 79.3% in July 2018. Of those tested, asymptomatic infection with malaria parasites reduced from 36.3% (1795/4941) in July 2017 to 32.9% (1303/3966) in July 2018 (p = 0.001). Prevalence of asymptomatic parasitaemia among children under 15 years declined from 52.6% (1043/1984) in July 2017 to 47.5% (820/1728) in July 2018 (p = 0.002). Implementing MTTT significantly reduced asymptomatic parasitaemia by 24% from July 2017 to July 2018 after adjusting for age, ITN use and axillary temperature (OR = 0.76, CI = 0.67, 0.85 p ≤ 0.001).

Conclusion: This study has demonstrated that implementing MTTT is feasible and could reduce the prevalence of asymptomatic malaria parasitaemia in children under 15 years of age. Furthermore, the use of community-based health volunteers could ensure high coverage at lower cost of implementation.

77.  Probing the Composition of Plasmodium Species Contained in Malaria Infections in the Eastern Region of Ghana

Linda Eva Amoah  ^{1   2} , Dickson Donu  ³ , Benjamin Abuaku  ⁴ , Colins Ahorlu  ⁴ , Daniel Arhinful  ⁴ , Edwin Afari  ⁵ , Keziah Malm  ⁶ , Kwadwo Ansah Koram  ^{7   4}

BMC Public Health. 2019 Dec 2;19(1):1617. doi: 10.1186/s12889-019-7989-1.

 

Abstract

Background: Asymptomatic falciparum and non-falciparum malaria infections are major challenges to malaria control interventions, as they remain a source of continual infection in the community. This becomes even more important as the debate moves towards elimination and eradication. This study sought to quantify the burden of Plasmodium malaria infection in seven communities in the Eastern Region of Ghana.

Methods: The cross-sectional study recruited 729 participants aged 85 years old and below from 7 closely linked communities. Finger pricked blood was used to prepare thick and thin blood smears as well as spot filter paper and an histidine rich protein 2 (HRP2) rapid diagnostic test kit (RDT). Genomic DNA was extracted from the filter paper dry blood spot (DBS) and used in PCR to amplify the Plasmodium 18S rRNA gene using species specific PCR.

Results: 96.6% of the participants were identified as afebrile, with axillary temperatures below 37.5 °C. PCR identified 66% of the participants to harbor malaria parasites, with 9 P. malariae and 7 P. ovale mono-infections accounting for 2.2% and P. falciparum combined with either 36 P. malariae or 25 P. ovale infections, accounting for 13.3%. Parasite prevalence by microscopy (32%) was similar to the RDT positivity rate (33%). False positive RDT results ranged from 64.6% in children aged between 5 and 9 years to 10% in adults aged 20 years and above. No significant differences were observed in falciparum and non-falciparum parasite carriage at the community level, however young adults aged between 15 and 19 years had the highest prevalence (34.8% (16/46)) of P. falciparum and P. malariae parasite carriage whilst children aged between 5 and 9 years had the highest level (11.4% (14/123)) of P. ovale carriage.

Conclusion: The high rate of misidentification of non-falciparum parasites and the total absence of detection of P. ovale by microscopy suggests that more sensitive malaria diagnostic tools including molecular assays are required to accurately determine the prevalence of carriers of non-falciparum parasites and low density P. falciparum infections, especially during national surveillance exercises. Additionally, malaria control interventions targeting the non-falciparum species P. malariae and P. ovale parasites are needed.