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1.
Heliyon ; 9(11): e21659, 2023 Nov.
Article in English | MEDLINE | ID: mdl-38027824

ABSTRACT

Frequent occurrence of drought, heat, low soil fertility and Striga infestation are the main stress factors reducing maize yield in the Sahel. Adoption of stable multiple stress tolerant maize cultivars in the region is crucial for achieving food security. However, selection of a stable high yielding cultivar is complicated by genotype × environment interaction (GEI) due to differential responses to growing conditions. Eleven extra-early maturing multiple-stress tolerant maize hybrids and two checks arranged in a randomized complete block design was evaluated across nine locations for two years in Mali and Niger. The objectives of this study were to identify (i) stable and high-yielding maize hybrids, and (ii) suitable test locations for selecting promising extra-early maize hybrids. GGE biplot was used for graphical analysis. Significant genotype, location and GEI effects were detected for grain yield and number of ears per plant. EEWQH-13 produced the highest grain yield (3860 kg ha-1) while EEYQH-1 had the poorest yield (2663 kg ha-1) with trial mean of 3395 kg ha-1 for all hybrids. GGE biplot explained 69.6 % of the total variation in grain yield among the hybrids. The polygon view identified EEWQH-13 as the best hybrid across six of the nine test locations. EEPVAH-58 was identified as the most stable high yielding hybrid across the nine test locations followed by EEWQH-16 and EEWQH-13. The nine locations were clustered under two mega-environments (ME1, ME2). Among the nine test locations, Tara and Aderaoua clustered in ME1 were the most suitable ones for selecting promising extra-early maize hybrids for wider adaptation. The three hybrids, EEPVAH-58, EEWQH-16, and EEWQH-13, identified in this study could be recommended for on-farm evaluation to confirm the consistency of their yield performance for possible release and commercialization in Mali and Niger.

2.
PLoS Negl Trop Dis ; 17(11): e0011632, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37967137

ABSTRACT

BACKGROUND: Onchocerciasis control activities in Mali began in 1975 with vector larviciding carried out by the Onchocerciasis Control Programme (OCP), followed by the distribution of ivermectin from 1998 until the closure of the OCP in 2002. At that time, epidemiological evaluations, using skin snip microscopy and O-150 pool screening PCR in black flies, indicated that the disease had been largely controlled as a public health problem. Ivermectin distribution was nevertheless continued after 2002 in 34 of the 75 health districts in Mali as these were known to still be meso- or hyper-endemic for onchocerciasis. In addition, the onchocerciasis sites known to be hypo-endemic for onchocerciasis benefited from the distribution of ivermectin treatment as part of the mass drug administration (MDA) program for lymphatic filariasis. Various entomological and epidemiological evaluations have now indicated that Mali may have achieved successful interruption of onchocerciasis transmission. METHODS: A series of cross-sectional surveys to update vector breeding sites throughout the endemic areas, followed by a pre-stop ivermectin mass drug administration (Pre-stop MDA) survey, were undertaken in 2019-2020. Based on breeding site findings, historical epidemiological assessments, and vector collection site maps, 18 operational transmission zones (OTZ) were delineated within which a total of 104 first line villages were selected for evaluation. Dried blood spots (DBS) samples were collected from 10,400 children (5-9 years old) from these 104 first line villages and processed for the presence of OV16 antibody using a lab-based rapid diagnostic test. RESULTS: Within the 544 Simulium damnosum s.l. breeding sites visited in all five endemic onchocerciasis endemic regions of Mali 18.01% (98/544) were seen to be active with the presence of at least one stage of S. damnosum. The overall prevalence of OV16 positive children was 0.45% (47/10,400). However, two hotspots were identified: 2.60% (13/500) seroprevalence in the OTZ number 5 in Kayes Region and 1.40% (7/500) in the OTZ number 1 of Sikasso Region. CONCLUSION: These data show that onchocerciasis prevalence in the five endemic regions has declined to levels that indicate that Stop-MDA surveys should be now carried out in most of the OTZ except for one in the Kayes Region. This latter site will need additional ivermectin treatment before reevaluation, and an OTZ in the Sikasso Region requires revaluation before possibly reinitiating MDA.


Subject(s)
Onchocerciasis , Simuliidae , Child , Animals , Humans , Child, Preschool , Onchocerciasis/drug therapy , Onchocerciasis/epidemiology , Onchocerciasis/prevention & control , Ivermectin/therapeutic use , Mass Drug Administration , Mali/epidemiology , Seroepidemiologic Studies , Cross-Sectional Studies
3.
J Clin Tuberc Other Mycobact Dis ; 33: 100389, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37637324

ABSTRACT

Background: Contribution of host factors in mediating susceptibility to extrapulmonary tuberculosis is not well understood. Objective: To examine the influence of patient sex on anatomical localization of extrapulmonary tuberculosis. Methods: We conducted a retrospective cross-sectional study in Mali, West Africa. Hospital records of 1,304 suspected cases of extrapulmonary tuberculosis, available in TB Registry of a tertiary tuberculosis referral center from 2019 to 2021, were examined. Results: A total of 1,012 (77.6%) were confirmed to have extrapulmonary tuberculosis with a male to female ratio of 1.59:1. Four clinical forms of EPTB predominated, namely pleural (40.4%), osteoarticular (29.8%), lymph node (12.5%), and abdominal TB (10.3%). We found sex-based differences in anatomical localization of extrapulmonary tuberculosis, with males more likely than females to have pleural TB (OR: 1.51; 95% CI [1.16 to 1.98]). Conversely, being male was associated with 43% and 41% lower odds of having lymph node and abdominal TB, respectively (OR: 0.57 and 0.59). Conclusion: Anatomical sites of extrapulmonary tuberculosis differ by sex with pleural TB being associated with male sex while lymph node and abdominal TB are predominately associated with female sex. Future studies are warranted to understand the role of sex in mediating anatomical site preference of tuberculosis.

4.
Lancet Infect Dis ; 23(11): 1266-1279, 2023 11.
Article in English | MEDLINE | ID: mdl-37499679

ABSTRACT

BACKGROUND: Malaria transmission-blocking vaccines target mosquito-stage parasites and will support elimination programmes. Gamete vaccine Pfs230D1-EPA/Alhydrogel induced superior activity to zygote vaccine Pfs25-EPA/Alhydrogel in malaria-naive US adults. Here, we compared these vaccines in malaria-experienced Malians. METHODS: We did a pilot safety study then double-blind, block-randomised, comparator-controlled main-phase trial in malaria-intense Bancoumana, Mali. 18-50-year-old healthy non-pregnant, non-breastfeeding consenting adult residents were randomly assigned (1:1:1:1) to receive four doses at months 0, 1, 4·5, and 16·5 of either 47 µg Pfs25, 40 µg Pfs230D1 or comparator (Twinrix or Menactra)-all co-administered with normal saline for blinding-or 47 µg Pfs25 plus 40 µg Pfs230D1 co-administered. We documented safety and tolerability (primary endpoint in the as-treated populations) and immunogenicity (secondary endpoint in the as-treated populations: ELISA, standard-membrane-feeding assay, and mosquito direct skin feed assay). This trial is registered at ClinicalTrials.gov, NCT02334462. FINDINGS: Between March 19, and June 2, 2015, we screened 471 individuals. Of 225 enrolled for the pilot and main cohorts, we randomly assigned 25 participants to pilot safety cohort groups of five (20%) to receive a two-dose series of Pfs25-EPA/Alhydrogel (16 µg), Pfs230D1-EPA/Alhydrogel (15 µg) or comparator, followed by Pfs25-EPA/Alhydrogel (16 µg) plus Pfs230D1-EPA/Alhydrogel (15 µg) or comparator plus saline. For the main cohort, we enrolled 200 participants between May 11 and June 2, 2015, to receive a four-dose series of 47 µg Pfs25-EPA/Alhydrogel plus saline (n=50 [25%]; Pfs25), 40 µg Pfs230D1-EPA/Alhydrogel plus saline (n=49 [25%]; Pfs230D1), 47 µg Pfs25-EPA/Alhydrogel plus 40 µg Pfs230D1-EPA/Alhydrogel (n=50 [25%]; Pfs25 plus Pfs230D1), or comparator (Twinrix or Menactra) plus saline (n=51 [25%]). Vaccinations were well tolerated in the pilot safety and main phases. Most vaccinees became seropositive after two Pfs230D1 or three Pfs25 doses; peak titres increased with each dose thereafter (Pfs230D1 geometric mean: 77·8 [95% CI 56·9-106·3], 146·4 [108·3-198·0], and 410·2 [301·6-558·0]; Pfs25 geometric mean 177·7 [130·3-242·4] and 315·7 [209·9-474·6]). Functional activity (mean peak transmission-reducing activity) appeared for Pfs230D1 (74·5% [66·6-82·5]) and Pfs25 plus Pfs230D1 (68·6% [57·3-79·8]), after the third dose and after the fourth dose (88·9% [81·7-96·2] for Pfs230D1 and 85·0% [78·4-91·5] Pfs25 plus Pfs230D1) but not for Pfs25 (58·2% [49·1-67·3] after the third dose and 58·2% [48·5-67·9] after the fourth dose). Pfs230D1 transmission-reducing activity (73·7% [64·1-83·3]) persisted 10 weeks after the fourth dose. Transmission-reducing activity of 80% was estimated at 1659 ELISA units for Pfs25, 218 for Pfs230D1, and 223 for Pfs230D1 plus Pfs25. After 3850 direct skin feed assays, 35 participants (12 Pfs25, eight Pfs230D1, five Pfs25 plus Pfs230D1, and ten comparator) had transmitted parasites at least once. The proportion of positive assays in vaccine groups (Pfs25 33 [3%] of 982 [-0·013 to 0·014], Pfs230D1 22 [2%] of 954 [-0·005 to 0·027], and combination 11 [1%] of 940 [-0·024 to 0·002]) did not differ from that of the comparator (22 [2%] of 974), nor did Pfs230D1 and combination groups differ (-0·024 to 0·001). INTERPRETATION: Pfs230D1 but not Pfs25 vaccine induces durable serum functional activity in Malian adults. Direct skin feed assays detect parasite transmission to mosquitoes but increased event rates are needed to assess vaccine effectiveness. FUNDING: Intramural Research Program of the National Institute of Allergy and Infectious Diseases and US National Institutes of Health.


Subject(s)
Malaria Vaccines , Malaria, Falciparum , Meningococcal Vaccines , Animals , Adult , Humans , Adolescent , Young Adult , Middle Aged , Aluminum Hydroxide , Plasmodium falciparum , Malaria Vaccines/adverse effects , Double-Blind Method , Immunogenicity, Vaccine
5.
Trends Biotechnol ; 41(2): 154-164, 2023 02.
Article in English | MEDLINE | ID: mdl-35868886

ABSTRACT

Engineered gene drives, which bias their own inheritance to increase in frequency in target populations, are being developed to control mosquito malaria vectors. Such mosquitoes can belong to complexes of both vector and nonvector species that can produce fertile interspecific hybrids, making vertical gene drive transfer (VGDT) to sibling species biologically plausible. While VGDT to other vectors could positively impact human health protection goals, VGDT to nonvectors might challenge biodiversity ones. Therefore, environmental risk assessment of gene drive use in species complexes invites more nuanced considerations of target organisms and nontarget organisms than for transgenes not intended to increase in frequency in target populations. Incorporating the concept of target species complexes offers more flexibility when assessing potential impacts from VGDT.


Subject(s)
Anopheles , Gene Drive Technology , Animals , Humans , Anopheles/genetics , Mosquito Control , Mosquito Vectors/genetics , Transgenes
6.
Front Bioeng Biotechnol ; 11: 1286694, 2023.
Article in English | MEDLINE | ID: mdl-38249804

ABSTRACT

From 2012 to 2023, the Malaria Research and Training Center (MRTC), based out of the University of Sciences, Techniques and Technologies of Bamako (USTTB), was part of the Target Malaria research consortium working towards developing novel gene drive-based tools for controlling populations of malaria vector mosquitoes. As part of this work, Target Malaria Mali has undertaken a range of in-depth engagement activities with the communities where their research is conducted and with other stakeholders nationally. These activities were meant to ensure that the project's activities took place with the agreement of those communities, and that those communities were able to play a role in shaping the project's approach to ensure that its eventual outcomes were in line with their needs and concerns. This paper aims to conduct a critical assessment of those 10 years of stakeholder engagement in order to identify good practices which can inform future engagement work on gene drive research in West Africa. It sets out a range of approaches and practices that enabled the Target Malaria Mali team to engage a variety of stakeholders, to share information, collect feedback, and determine community agreement, in a manner that was inclusive, effective, and culturally appropriate. These can be useful tools for those working on gene drive research and other area-wide vector control methods in West African contexts to ensure that their research is aligned with the interests of the communities who are intended to be its ultimate beneficiaries, and to allow those communities to play a meaningful role in the research process.

7.
Antimicrob Agents Chemother ; 66(12): e0100122, 2022 12 20.
Article in English | MEDLINE | ID: mdl-36321830

ABSTRACT

The discovery and development of transmission-blocking therapies challenge malaria elimination and necessitate standard and reproducible bioassays to measure the blocking properties of antimalarial drugs and candidate compounds. Most of the current bioassays evaluating the transmission-blocking activity of compounds rely on laboratory-adapted Plasmodium strains. Transmission-blocking data from clinical gametocyte isolates could help select novel transmission-blocking candidates for further development. Using freshly collected Plasmodium falciparum gametocytes from asymptomatic individuals, we first optimized ex vivo culture conditions to improve gametocyte viability and infectiousness by testing several culture parameters. We next pre-exposed ex vivo field-isolated gametocytes to chloroquine, dihydroartemisinin, primaquine, KDU691, GNF179, and oryzalin for 48 h prior to direct membrane feeding. We measured the activity of the drug on the ability of gametocytes to resume the sexual life cycle in Anopheles after drug exposure. Using 57 blood samples collected from Malian volunteers aged 6 to 15 years, we demonstrate that the infectivity of freshly collected field gametocytes can be preserved and improved ex vivo in a culture medium supplemented with 10% horse serum at 4% hematocrit for 48 h. Moreover, our optimized drug assay displays the weak transmission-blocking activity of chloroquine and dihydroartemisinin, while primaquine and oryzalin exhibited a transmission-blocking activity of ~50% at 1 µM. KDU691 and GNF179 both interrupted Plasmodium transmission at 1 µM and 5 nM, respectively. This new approach, if implemented, has the potential to accelerate the screening of compounds with transmission-blocking activity.


Subject(s)
Antimalarials , Malaria, Falciparum , Humans , Plasmodium falciparum , Primaquine , Malaria, Falciparum/prevention & control , Antimalarials/pharmacology , Antimalarials/therapeutic use , Chloroquine/pharmacology , Chloroquine/therapeutic use
8.
Am J Trop Med Hyg ; 107(4_Suppl): 75-83, 2022 10 11.
Article in English | MEDLINE | ID: mdl-36228923

ABSTRACT

This article highlights over a decade of signature achievements by the West Africa International Centers for Excellence in Malaria Research (WA-ICEMR) and its partners toward guiding malaria prevention and control strategies. Since 2010, the WA-ICEMR has performed longitudinal studies to monitor and assess malaria control interventions with respect to space-time patterns, vector transmission indicators, and drug resistance markers. These activities were facilitated and supported by the Mali National Malaria Control Program. Research activities included large-scale active and passive surveillance and expanded coverage of universal long-lasting insecticide-treated bed nets and seasonal malaria chemoprevention (SMC). The findings revealed substantial declines in malaria occurrence after the scale-up of control interventions in WA-ICEMR study sites. WA-ICEMR studies showed that SMC using sulfadoxine-pyrimethamine plus amodiaquine was highly effective in preventing malaria among children under 5 years of age. An alternative SMC regimen (dihydroartemisinin plus piperaquine) was shown to be potentially more effective and provided advantages for acceptability and compliance over the standard SMC regimen. Other findings discussed in this article include higher observed multiplicity of infection rates for malaria in historically high-endemic areas, continued antimalarial drug sensitivity to Plasmodium falciparum, high outdoor malaria transmission rates, and increased insecticide resistance over the past decade. The progress achieved by the WA-ICEMR and its partners highlights the critical need for maintaining current malaria control interventions while developing novel strategies to disrupt malaria transmission. Enhanced evaluation of these strategies through research partnerships is particularly needed in the wake of reported artemisinin resistance in Southeast Asia and East Africa.


Subject(s)
Antimalarials , Artemisinins , Malaria, Falciparum , Malaria , Amodiaquine/therapeutic use , Antimalarials/therapeutic use , Artemisinins/therapeutic use , Child , Child, Preschool , Drug Combinations , Humans , Malaria/drug therapy , Malaria/epidemiology , Malaria/prevention & control , Malaria, Falciparum/drug therapy , Malaria, Falciparum/epidemiology , Malaria, Falciparum/prevention & control , Mali/epidemiology
9.
Parasit Vectors ; 15(1): 381, 2022 Oct 21.
Article in English | MEDLINE | ID: mdl-36271451

ABSTRACT

Arboviral diseases such as dengue, Zika and chikungunya transmitted by Aedes mosquitoes have been reported in 34 African countries. Available data indicate that in recent years there have been dengue and chikungunya outbreaks in the West Africa subregion, in countries including Côte d'Ivoire, Burkina Faso, Gabon, Senegal, and Benin. These viral diseases are causing an increased public health burden, which impedes poverty reduction and sustainable development. Aedes surveillance and control capacity, which are key to reducing the prevalence of arboviral infections, need to be strengthened in West Africa, to provide information essential for the formulation of effective vector control strategies and the prediction of arboviral disease outbreaks. In line with these objectives, the West African Aedes Surveillance Network (WAASuN) was created in 2017 at a meeting held in Sierra Leone comprising African scientists working on Aedes mosquitoes. This manuscript describes the proceedings and discusses key highlights of the meeting.


Subject(s)
Aedes , Arbovirus Infections , Chikungunya Fever , Dengue , Zika Virus Infection , Zika Virus , Animals , Humans , Mosquito Vectors , Zika Virus Infection/epidemiology , Zika Virus Infection/prevention & control , Cote d'Ivoire/epidemiology , Dengue/epidemiology
10.
Am J Trop Med Hyg ; 107(2): 433-440, 2022 08 17.
Article in English | MEDLINE | ID: mdl-35895582

ABSTRACT

Men and women often respond differently to infectious diseases and their treatments. Tuberculosis (TB) is a life-threatening communicable disease that affects more men than women globally. Whether male sex is an independent risk factor for unfavorable TB outcomes, however, has not been rigorously investigated in an African context, where individuals are likely exposed to different microbial and environmental factors. We analyzed data collected from a cohort study in Mali by focusing on newly diagnosed active pulmonary TB individuals who were treatment naive. We gathered baseline demographic, clinical, and microbiologic characteristics before treatment initiation and also at three time points during treatment. More males than females were affected with TB, as evidenced by a male-to-female ratio of 2.4:1. In addition, at baseline, males had a significantly higher bacterial count and shorter time to culture positivity as compared with females. Male sex was associated with lower smear negativity rate after 2 months of treatment also known as the intensive phase of treatment, but not at later time points. There was no relationship between patients' sex and mortality from any cause during treatment. This study suggests that sex-based differences in TB outcomes exist, with sex-specific effects on disease outcomes being more pronounced before treatment initiation and during the intensive phase of treatment rather than at later phases of treatment.


Subject(s)
Tuberculosis, Pulmonary , Tuberculosis , Female , Humans , Male , Tuberculosis, Pulmonary/drug therapy , Tuberculosis, Pulmonary/epidemiology , Tuberculosis, Pulmonary/diagnosis , Cohort Studies , Mali/epidemiology , Sex Characteristics , Tuberculosis/diagnosis , Antitubercular Agents/therapeutic use , Sputum/microbiology
11.
Article in English | MEDLINE | ID: mdl-35726222

ABSTRACT

Western Africa is vulnerable to arboviral disease transmission, having recently experienced major outbreaks of chikungunya, dengue, yellow fever and Zika. However, there have been relatively few studies on the natural history of the two major human arbovirus vectors in this region, Aedes aegypti and Ae. albopictus, potentially limiting the implementation of effective vector control. We systematically searched for and reviewed relevant studies on the behaviour and ecology of Ae. aegypti and Ae. albopictus in Western Africa, published over the last 40 years. We identified 73 relevant studies, over half of which were conducted in Nigeria, Senegal, or Côte d'Ivoire. Most studies investigated the ecology of Ae. aegypti and Ae. albopictus, exploring the impact of seasonality and land cover on mosquito populations and identifying aquatic habitats. This review highlights the adaptation of Ae. albopictus to urban environments and its invasive potential, and the year-round maintenance of Ae. aegypti populations in water storage containers. However, important gaps were identified in the literature on the behaviour of both species, particularly Ae. albopictus. In Western Africa, Ae. aegypti and Ae. albopictus appear to be mainly anthropophilic and to bite predominantly during the day, but further research is needed to confirm this to inform planning of effective vector control strategies. We discuss the public health implications of these findings and comment on the suitability of existing and novel options for control in Western Africa.

12.
Malar J ; 21(1): 152, 2022 May 25.
Article in English | MEDLINE | ID: mdl-35614489

ABSTRACT

Building on an exercise that identified potential harms from simulated investigational releases of a population suppression gene drive for malaria vector control, a series of online workshops identified nine recommendations to advance future environmental risk assessment of gene drive applications.


Subject(s)
Anopheles , Gene Drive Technology , Malaria , Animals , Anopheles/genetics , Malaria/prevention & control , Mosquito Control , Mosquito Vectors/genetics , Risk Assessment
13.
Sci Rep ; 12(1): 8271, 2022 05 18.
Article in English | MEDLINE | ID: mdl-35585101

ABSTRACT

Malaria is the leading cause of morbidity and mortality in Mali. Between 2017 and 2020, the number of cases increased in the country, with 2,884,827 confirmed cases and 1454 reported deaths in 2020. We performed a malaria risk stratification at the health district level in Mali with a view to proposing targeted control interventions. Data on confirmed malaria cases were obtained from the District Health Information Software 2, data on malaria prevalence and mortality in children aged 6-59 months from the 2018 Demographic and Health Survey, entomological data from Malian research institutions working on malaria in the sentinel sites of the National Malaria Control Program (NMCP), and environmental data from the National Aeronautics and Space Administration. A stratification of malaria risk was performed. Targeted malaria control interventions were selected based on spatial heterogeneity of malaria incidence, malaria prevalence in children, vector resistance distribution, health facility usage, child mortality, and seasonality of transmission. These interventions were discussed with the NMCP and the different funding partners. In 2017-2019, median incidence across the 75 health districts was 129.34 cases per 1000 person-years (standard deviation = 86.48). Risk stratification identified 12 health districts in very low transmission areas, 19 in low transmission areas, 20 in moderate transmission areas, and 24 in high transmission areas. Low health facility usage and increased vector resistance were observed in high transmission areas. Eight intervention combinations were selected for implementation. Our work provides an updated risk stratification using advanced statistical methods to inform the targeting of malaria control interventions in Mali. This stratification can serve as a template for continuous malaria risk stratifications in Mali and other countries.


Subject(s)
Malaria , Animals , Child , Disease Vectors , Humans , Incidence , Malaria/epidemiology , Malaria/prevention & control , Mali/epidemiology , Prevalence
14.
Trials ; 23(1): 259, 2022 Apr 05.
Article in English | MEDLINE | ID: mdl-35382856

ABSTRACT

BACKGROUND: Spatial repellents have been widely used for the prevention of mosquito bites but their efficacy in reducing mosquito-borne diseases has never been evaluated in Africa. Additionally, spatial repellents have the potential of being critical tools in the prevention of mosquito-borne diseases in contexts where typical vectors control efforts such as insecticide-treated nets (ITNs) and indoor residual spray (IRS) are inaccessible or underutilized such as among displaced populations or in emergency relief settings. To address this knowledge gap, Kolondieba District, Sikasso Region, Mali was selected as a site to estimate the impact of the Mosquito Shield™, a spatial repellent that incorporates transfluthrin on a plastic sheet, on malaria-related outcomes. Over the past decade, the Region of Sikasso, Health districts of Kadiolo, Yorosso, and Kolondieba have remained among the most afflicted, characterized by an annual parasite incidence of more than 116 cases per 1000 population [1] and a Plasmodium falciparum prevalence rate of 29.7% [2]. METHODS: Cluster-randomized, placebo-controlled, double-blinded clinical trial, whereby children ≥ 6 months to < 10 years old will be enrolled and followed to determine the time to malaria infection with monthly blood samples for microscopic diagnosis. A total of 1920 subjects (HHs) will be enrolled in 60 clusters (30 spatial repellent, 30 placebo). Malaria incidence will be estimated and compared to demonstrate and quantify the protective efficacy (PE) of a spatial repellent, in reducing malaria infection. Monthly mosquito collections using CDC light traps will be conducted to determine if there are entomological correlates of spatial repellent efficacy that may be useful for the evaluation of new spatial repellents. Quarterly human landing catches (HLC) will assess the behavioral effects of the intervention. DISCUSSION: Findings will serve as an efficacy trial of spatial repellent products for sub-Saharan Africa. Findings will be submitted to the World Health Organization Vector Control Advisory Group (WHO VCAG) for assessment of whether spatial repellents have "public health value." Entomological outcomes will also be measured as proxies of malaria transmission to help develop guidelines for the evaluation of future spatial repellent products. TRIAL REGISTRATION: ClinicalTrials.gov NCT04795648 . Registered on March 12, 2021.


Subject(s)
Insect Repellents , Insecticide-Treated Bednets , Insecticides , Malaria , Animals , Child , Humans , Incidence , Infant , Insecticides/pharmacology , Malaria/epidemiology , Malaria/prevention & control , Mali/epidemiology , Mosquito Control/methods , Randomized Controlled Trials as Topic
15.
Malar J ; 21(1): 65, 2022 Feb 23.
Article in English | MEDLINE | ID: mdl-35197053

ABSTRACT

BACKGROUND: Over the past decade, three strategies have reduced severe malaria cases and deaths in endemic regions of Africa, Asia and the Americas, specifically: (1) artemisinin-based combination therapy (ACT); (2) insecticide-treated bed nets (ITNs); and, (3) intermittent preventive treatment with sulfadoxine-pyrimethamine in pregnancy (IPTp). The rationale for this study was to examine communities in Dangassa, Mali where, in 2015, two additional control strategies were implemented: ITN universal coverage and seasonal malaria chemoprevention (SMC) among children under 5 years old. METHODS: This was a prospective study based on a rolling longitudinal cohort of 1401 subjects participating in bi-annual smear surveys for the prevalence of asymptomatic Plasmodium falciparum infection and continuous surveillance for the incidence of human disease (uncomplicated malaria), performed in the years from 2012 to 2020. Entomological collections were performed to examine the intensity of transmission based on pyrethroid spray catches, human landing catches and enzyme-linked immunosorbent assay (ELISA) testing for circumsporozoite antigen. RESULTS: A total of 1401 participants of all ages were enrolled in the study in 2012 after random sampling of households from the community census list. Prevalence of infection was extremely high in Dangassa, varying from 9.5 to 62.8% at the start of the rainy season and from 15.1 to 66.7% at the end of the rainy season. Likewise, the number of vectors per house, biting rates, sporozoites rates, and entomological inoculation rates (EIRs) were substantially greater in Dangassa. DISCUSSION: The findings for this study are consistent with the progressive implementation of effective malaria control strategies in Dangassa. At baseline (2012-2014), prevalence of P. falciparum was above 60% followed by a significant year-to-year decease starting in 2015. Incidence of uncomplicated infection was greater among children < 5 years old, while asymptomatic infection was more frequent among the 5-14 years old. A significant decrease in EIR was also observed from 2015 to 2020. Likewise, vector density, sporozoite rates, and EIRs decreased substantially during the study period. CONCLUSION: Efficient implementation of two main malaria prevention strategies in Dangassa substantially contribute to a reduction of both asymptomatic and symptomatic malaria from 2015 to 2020.


Subject(s)
Insecticide-Treated Bednets , Malaria, Falciparum , Malaria , Adolescent , Child , Child, Preschool , Humans , Malaria/epidemiology , Malaria/prevention & control , Malaria, Falciparum/epidemiology , Malaria, Falciparum/prevention & control , Mali/epidemiology , Prospective Studies
16.
Mali Med ; 37(1): 49-53, 2022.
Article in French | MEDLINE | ID: mdl-38196259

ABSTRACT

The rapid access of the population to basic and comprehensive health care determines the prognosis of the disease and decreases mortality and morbidity. METHODOLOGY: we carried out a prospective study over 12 months at the Bla Reference Health Center. All patients evacuated for obstetric complications were included. Women admitted on an emergency basis by self-referral were not included. The data was analyzed from the software Epi Info version: 3.5.4, the text entry from the software version Word 2013. RESULTS: We recorded 430 evacuations or 42.36% of admissions to the maternity hospital in Bla. The patients were young under 20 years 17.9% (n = 77), nulliparous 22.1% (n = 95). They had not performed an antenatal consultation in 30.7% of cases (n = 132). Matrons evacuated in 50.2% of cases (n = 216). The transfer diagnosis was hemorrhage in 14.2% of cases. The main intervention performed was cesarean section (92.3% of cases). The evacuation time was greater than one hour in 95.1% (n = 21). The actors for the financing of the fund were the district council, the town halls and the Community Health Associations (ASACO). The mobilization rate of ASACOs was 82%, that of town halls 17%. The circle council did not pay its quota. CONCLUSION: A better financial involvement of the communities in the management of the evacuation reference system in the health district of Bla is a necessity.


L'accès rapide de la population aux soins de santé de base et complet détermine le pronostic de la maladie et diminue la mortalité et la morbidité. MÉTHODOLOGIE: nous avons mené une étude prospective sur 12 mois au Centre de Santé de Référence de Bla. Ont été incluses toutes les patientes évacuées pour complications obstétricales. Les femmes admises en urgence par autoréférence n'ont pas été incluses. Les données ont été analysées à partir du logiciel Epi Info version : 3.5.4, la saisie des textes à partir du logiciel version Word 2013. RÉSULTATS: Nous avons enregistré 430 évacuations soit 42,36% des admissions à la maternité de Bla. Les patientes étaient jeunesmoins de 20 ans 17,9% (n=77), des nullipares 22.1% (n=95). Ellesn'avaient pas réalisé de consultation prénatale dans 30,7%des cas (n=132). Les matrones ont évacué dans 50,2% de cas (n=216). Le diagnostic de transfertétait l'hémorragie dans 14,2% de cas. La principale intervention pratiquée était la césarienne (92,3%des cas). Le délai d'évacuation était supérieur à une heure dans 95,1% (n=21). Les acteurs pour le financement de la caisse étaient le conseil de cercle, les mairies et les Associations de Santé Communautaires (ASACO). Le taux de mobilisation des ASACO a été de 82%, celui des mairies de17%. Le conseil de cercle n'a pas payé sa quote-part. CONCLUSION: Une meilleure implication financière des collectivités dans la gestion du système de référence évacuation dans le district sanitaire de Bla est une nécessité.

17.
Reprod Health ; 18(1): 243, 2021 Dec 03.
Article in English | MEDLINE | ID: mdl-34861876

ABSTRACT

BACKGROUND: Early adolescence is a critical period where social norms, attitudes, and behaviors around gender equality form. Social norms influence adolescent choices and behaviors and are reinforced by caregivers and community members, affecting girls' reproductive health and educational opportunities. Understanding how to shift these often-interconnected norms to delay child marriage, pregnancy and keep girls in school requires understanding of the structure and dynamics of family and community systems. The Senegalese and American non-governmental organization, the Grandmothers Project-Change through Culture, seeks to address these intertwined factors through innovative community change strategies that build on the specific structure and values of West African collectivist cultures. METHODS: The Girls' Holistic Development approach in rural Vélingara, Senegal posits that by increasing recognition, knowledge and empowerment of elder community women and reinforcing intergenerational communication and decision-making, community members including girls will support and advocate on behalf of girls' interests and desires. We assessed the Girls Holistic Development approach using Realist Evaluation with a mixed-method, quasi-experimental design with a comparison population. We examined differences in intergenerational communication, decision-making and descriptive and injunctive norms related to early marriage, pregnancy and schooling. RESULTS: After 18 months, intergenerational communication was more likely, grandmothers felt more valued in their communities, adolescent girls felt more supported with improved agency, and norms were shifting to support delayed marriage and pregnancy and keeping girls in school. Grandmothers in intervention villages were statistically significantly more likely to be perceived as influential decision-makers by both VYA girls and caregivers for marriage and schooling decisions compared to girls and caregivers in comparison villages. CONCLUSIONS: This realist evaluation demonstrated shift in social norms, particularly for VYA girls, in intervention villages favoring delaying girls' marriage, preventing early pregnancy and keeping girls in school along with increased support for and action by grandmothers to support girls and their well-being related to these same outcomes. These shifts represent greater community social cohesion on girl-child issues. This research helps explain the linkage between social norms and girls' reproductive health and education outcomes and demonstrates that normative shifts can lead to behavior change via collective community action mechanisms.


During adolescence in Senegal, as elsewhere, decisions on whether to keep girls in school and at what age to marry girls are made by their caregivers and influenced by family and community members. Early pregnancy occurs at these ages, either before or during marriage. These social influences, called social norms, set expectations for parents and girls.The Grandmothers Project­Change through Culture developed an intervention to shift social norms and change these three outcomes­early pregnancy, early marriage and keeping girls in school. The project, called Girls Holistic Development (GHD), builds on local relationships between girls, grandmothers, parents and community leaders and local values to facilitate discussion, reflection, collaboration and advocacy.This study used realist evaluation methods, including qualitative and quantitative interview and focus group discussions, to understand whether these shifts in norms and behaviors took place. Research took place with girls, grandmothers and male and female caregivers 18 months after GHD started. Quantitative survey included 7 intervention and 7 comparison villages.Results supported GHDs' expectations and strategy. In intervention villages, grandmothers and girls reported closer relationships; parents considered grandmothers important sources of advice. Girls, grandmothers and caregivers described social expectations as favoring girl's education, marriage at older ages and development of strategies to prevent girl's pregnancy in intervention villages.This evaluation provided strong support for GHDs' ability to shift social norms to improve girls' outcomes. By working with local relationships and values, GHD created more communication between community and family members and facilitated increased social bonds within the community.


Subject(s)
Child Health , Social Norms , Adolescent , Aged , Child , Female , Humans , Marriage , Pregnancy , Senegal , Social Cohesion
18.
Afr J Prim Health Care Fam Med ; 13(1): e1-e3, 2021 Sep 30.
Article in English | MEDLINE | ID: mdl-34636617

ABSTRACT

Family medicine has not received appropriate attention in the sub-Saharan African context. In particular, family medicine is rarely recognised as a medical speciality and most African countries are silent on the role of family medicine in their health systems. There is, however, an emerging interest in developing family medicine as a key component of primary healthcare. Postgraduate training in family medicine is progressing and many countries have already established specific training programmes. In addition, there have been attempts to define the importance of family medicine, which, we expect, this short report contributes to. Interviews were conducted with physicians, partners and beneficiaries of two international development projects funded by the Canadian government. The one project supports training of health professionals and the other education of healthy women and girls in the community. The objective was to document the strengthening of primary healthcare through the creation and adaptation of a new family and community medicine postgraduate medical programme (which includes both family and community medicine) emphasising field training, immersion in local communities and interdisciplinary collaboration. This article underlines the importance of family medicine in Mali by documenting how what is now termed family and community medicine can promote community-orientated health services. To do so, we use the examples of initiatives and actions done through two international health development projects.


Subject(s)
Community Health Services , Family Practice , Canada , Female , Humans , Mali , Primary Health Care
19.
Methods Ecol Evol ; 12(6): 1008-1016, 2021 Jun.
Article in English | MEDLINE | ID: mdl-34249305

ABSTRACT

Current mark-release-recapture methodologies are limited in their ability to address complex problems in vector biology, such as studying multiple groups overlapping in space and time. Additionally, limited mark retention, reduced post-marking survival and the large effort in marking, collection and recapture all complicate effective insect tracking.We have developed and evaluated a marking method using a fluorescent dye (SmartWater®) combined with synthetic DNA tags to informatively and efficiently mark adult mosquitoes using an airbrush pump and nebulizer. Using a handheld UV flashlight, the fluorescent marking enabled quick and simple initial detection of recaptures in a field-ready and non-destructive approach that when combined with an extraction-free PCR on individual mosquito legs provides potentially unlimited marking information.This marking, first tested in the laboratory with Anopheles gambiae s.l. mosquitoes, did not affect survival (median ages 24-28 days, p-adj > 0.25), oviposition (median eggs/female of 28.8, 32.5, 33.3 for water, green, red dyes, respectively, p-adj > 0.44) or Plasmodium competence (mean oocysts 5.56-10.6, p-adj > 0.95). DNA and fluorescence had 100% retention up to 3 weeks (longest time point tested) with high intensity, indicating marks would persist longer.We describe a novel, simple, no/low-impact and long-lasting marking method that allows separation of multiple insect subpopulations by combining unlimited length and sequence variation in the synthetic DNA tags. This method can be readily deployed in the field for marking multiple groups of mosquitoes or other insects.

20.
Front Microbiol ; 12: 635772, 2021.
Article in English | MEDLINE | ID: mdl-34054746

ABSTRACT

Exposure of mosquitoes to numerous eukaryotic and prokaryotic microbes in their associated microbiomes has probably helped drive the evolution of the innate immune system. To our knowledge, a metagenomic catalog of the eukaryotic microbiome has not been reported from any insect. Here we employ a novel approach to preferentially deplete host 18S ribosomal RNA gene amplicons to reveal the composition of the eukaryotic microbial communities of Anopheles larvae sampled in Kenya, Burkina Faso and Republic of Guinea (Conakry). We identified 453 eukaryotic operational taxonomic units (OTUs) associated with Anopheles larvae in nature, but an average of 45% of the 18S rRNA sequences clustered into OTUs that lacked a taxonomic assignment in the Silva database. Thus, the Anopheles microbiome contains a striking proportion of novel eukaryotic taxa. Using sequence similarity matching and de novo phylogenetic placement, the fraction of unassigned sequences was reduced to an average of 4%, and many unclassified OTUs were assigned as relatives of known taxa. A novel taxon of the genus Ophryocystis in the phylum Apicomplexa (which also includes Plasmodium) is widespread in Anopheles larvae from East and West Africa. Notably, Ophryocystis is present at fluctuating abundance among larval breeding sites, consistent with the expected pattern of an epidemic pathogen. Species richness of the eukaryotic microbiome was not significantly different across sites from East to West Africa, while species richness of the prokaryotic microbiome was significantly lower in West Africa. Laboratory colonies of Anopheles coluzzii harbor 26 eukaryotic OTUs, of which 38% (n = 10) are shared with wild populations, while 16 OTUs are unique to the laboratory colonies. Genetically distinct An. coluzzii colonies co-housed in the same facility maintain different prokaryotic microbiome profiles, suggesting a persistent host genetic influence on microbiome composition. These results provide a foundation to understand the role of the Anopheles eukaryotic microbiome in vector immunity and pathogen transmission. We hypothesize that prevalent apicomplexans such as Ophryocystis associated with Anopheles could induce interference or competition against Plasmodium within the vector. This and other members of the eukaryotic microbiome may offer candidates for new vector control tools.

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