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Objectives: This study aims to identify the factors influencing vaccine hesitancy, willingness and its variation over time in order to inform more responsive strategies for increasing vaccination uptake. The specific objectives are: (1) to describe and compare levels of COVID-19 vaccine hesitancy among the general population in rural and urban settings in West Africa over time and (2) to identify factors associated with COVID-19 vaccination willingness and hesitancy among the general population across five West African countries over time., Design: Following a baseline survey (Wave I), three serial cross-sectional surveys (Waves II-IV) were implemented., Setting: The study was conducted in Burkina Faso, Guinea, Mali, Senegal and Sierra Leone from November 2021 to July 2022., Participants: A total of 13 571 study participants were included in the study (n=4373, n=4593 and n=4605 for survey Waves II, III and IV, respectively). Inclusion criteria were being 18 years or older, living in the study area and willing to provide informed consent. A two-stage sampling strategy was used to select the sample from among the general population., Primary and Secondary Outcomes: Primary outcomes were the variability of vaccine hesitancy over time and across the five West African countries. Secondary outcomes were factors associated with vaccine willingness., Results: A small but steady increase in hesitancy to COVID-19-vaccination can be observed across countries, with an upward trend of vaccine hesitancy reported by 952 participants (33.9 %) in Wave II, 1055 (37.3%) in Wave III and 1089 (38.1%) in Wave IV. Among the countries included, Senegal shows the highest level of vaccine hesitancy ('Definitely no' and 'Probably no' ranging from 50.2% to 56.0% and 26.2 to 28.3%, respectively). At the same time, Senegal has the lowest vaccination coverage overall. Across all five countries and survey waves, the primary factor associated with vaccination willingness is fear of experiencing severe COVID-19 disease (Wave II: OR 0.42, 95% CI 0.34 to 0.51, Wave III: OR 0.48, 95% CI 0.40 to 0.59 and Wave IV: OR 0.54, 95% CI 0.44 to 0.66). Perceived improved financial status seems to influence willingness to get vaccinated negatively (OR 0.57, 95% CI 0.40 to 0.81) and unlike in Western, Educated, Industrialised, Rich and Democratic countries, men seem more reluctant to get vaccinated than women (OR 0.77, 95%, CI 0.65 to 0.93)., Conclusions: Our findings suggest that vaccine hesitancy should be monitored over time to inform communication strategies, which are responsive to changes in vaccination-related public sentiments. Additionally, a focus on social solidarity and the importance of women in vaccination advocacy can help improve COVID-19 vaccination coverage in West Africa., Trial Registration Number: The general protocol is registered on clinicaltrial.gov (protocol number: NCT04912284)., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Antimalarial drugs that can block the transmission of Plasmodium gametocytes to mosquito vectors would be highly beneficial for malaria elimination efforts. Identifying transmission-blocking drugs currently relies on evaluation of their activity against gametocyte-producing laboratory parasite strains and would benefit from a testing pipeline with genetically diverse field isolates. The aims of this study were to develop a pipeline to test drugs against P. falciparum gametocyte field isolates and to evaluate the transmission-blocking activity of a set of novel compounds. Two assays were designed so they could identify both the overall transmission-blocking activity of a number of marketed and experimental drugs by direct membrane feeding assays (DMFA), and then also discriminate between those that are active against the gametocytes (gametocyte killing or sterilizing) or those that block development in the mosquito (sporontocidal). These DMFA assays used venous blood samples from naturally infected Plasmodium falciparum gametocyte carriers and locally reared Anopheles gambiae s.s. mosquitoes. Overall transmission-blocking activity was assessed following a 24 hour incubation of compound with gametocyte infected blood (TB-DMFA). Sporontocidal activity was evaluated following addition of compound directly prior to feeding, without incubation (SPORO-DMFA); Gametocyte viability was retained during 24-hour incubation at 37°C when gametocyte infected red blood cells were reconstituted in RPMI/serum. Methylene-blue, MMV693183, DDD107498, atovaquone and P218 showed potent transmission-blocking activity in the TB-DMFA, and both atovaquone and the novel antifolate P218 were potent inhibitors of sporogonic development in the SPORO-DMA. This work establishes a pipeline for the integral use of field isolates to assess the transmission-blocking capacity of antimalarial drugs to block transmission that should be validated in future studies., Competing Interests: No, the authors have declared that no competing interests exist., (Copyright: © 2023 B. Henry et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Chromosomal inversion polymorphisms have special importance in the Anopheles gambiae complex of malaria vector mosquitoes, due to their role in local adaptation and range expansion. The study of inversions in natural populations is reliant on polytene chromosome analysis by expert cytogeneticists, a process that is limited by the rarity of trained specialists, low throughput, and restrictive sampling requirements. To overcome this barrier, we ascertained tag single nucleotide polymorphisms (SNPs) that are highly correlated with inversion status (inverted or standard orientation). We compared the performance of the tag SNPs using two alternative high throughput molecular genotyping approaches vs. traditional cytogenetic karyotyping of the same 960 individual An. gambiae and An. coluzzii mosquitoes sampled from Burkina Faso, West Africa. We show that both molecular approaches yield comparable results, and that either one performs as well or better than cytogenetics in terms of genotyping accuracy. Given the ability of molecular genotyping approaches to be conducted at scale and at relatively low cost without restriction on mosquito sex or developmental stage, molecular genotyping via tag SNPs has the potential to revitalize research into the role of chromosomal inversions in the behavior and ongoing adaptation of An. gambiae and An. coluzzii to environmental heterogeneities., (Copyright © 2020 Love et al.)

The World Health Organization (WHO) has set the goal of gambiense-Human African trypanosomiasis (HAT) elimination as a public health problem for 2020 and interruption of transmission in humans for 2030. In this context, it is crucial to monitor progress towards these targets using accurate tools to assess the level of transmission in a given area. The aim of this study was to investigate the relevance of the immune trypanolysis test (TL) as a population-based bioassay to evaluate Trypanosoma brucei gambiense transmission in various epidemiological contexts. Significant correlations were observed between HAT endemicity levels and the percentage of TL-positive individuals in the population. TL therefore appears to be a suitable population-based biomarker of the intensity of transmission. In addition to being used as a tool to assess the HAT status at an individual level, assessing the proportion of TL positive individuals in the population appears as a promising and easy alternative to monitor the elimination of gambiense HAT in a given area., (© E. Dama et al., published by EDP Sciences, 2019.)

Background: A national subsidy policy was introduced in 2007 in Burkina Faso to improve financial accessibility to facility-based delivery. In this article, we estimated the effects of reducing user fees on institutional delivery and neonatal mortality, immediately and three years after the introduction of the policy., Methods: The study was based on a quasi-experimental design. We used data obtained from the 2010 Demographic and Health Survey, including survival information for 32,102 live-born infants born to 12,474 women. We used a multilevel Poisson regression model with robust variances to control for secular trends in outcomes between the period before the introduction of the policy (1 January, 2007) and the period after. In sensitivity analyses, we used two different models according to the different definitions of the period "before" and the period "after"., Results: Immediately following its introduction, the subsidy policy was associated with increases in institutional deliveries by 4% (RR = 1.04, 95% CI: 0.98-1.10) in urban areas and by 12% (RR = 1.12, 95% CI: 1.04-1.20) in rural areas. The results showed similar patterns in sensitivity analyses. This effect was particularly marked among rural clusters with low institutional delivery rates at baseline (RR = 1.44, 95% CI: 1.33-1.55). It was persistent for 42 months after the introduction of the policy but these increases were not statistically significant. At 42 months, the delivery rates had increased by 26% in rural areas (RR = 1.26; 95% CI: 0.86-1.86) and 13% (RR = 1.13; 95% CI: 0.88-1.46) in urban areas. There was no evidence of a significant decrease in neonatal mortality rates., Conclusion: The delivery subsidy implemented in Burkina Faso is associated with short-term increases in health facility deliveries. This policy has been particularly beneficial for rural households., Competing Interests: The authors have declared that no competing interests exist.

In this study, we characterize the ability of the previously described Infoscitex tent (IST) to capture mosquitoes in comparison to either the Centers for Disease Control Light Trap hung next to individuals under a bed net (LTC) or to human landing catches (HLC). In Senegal, the IST caught 6.14 times the number of Anopheles gambiae sensu lato (s.l.), and 8.78 times the Culex group V mosquitoes as LTC. In one of two locations in Burkina Faso, the IST caught An. gambiae at a rate not significantly different than HLC. Of importance, 9.1-36.1% of HLC caught An. gambiae were blood fed, mostly with fresh blood, suggesting they fed upon the collector, whereas only 0.5-5.0% from the IST had partial or old blood. The IST also caught outdoor biting species in proportions comparable to HLC. The results show this tent provides a safer and effective alternative to the skill-dependent, risky, and laborious HLC method., (© The American Society of Tropical Medicine and Hygiene.)

Objective: Several countries in sub-Saharan Africa have implemented policies to remove or reduce user fees. Our aim was to identify criteria guiding such decisions among national policy entrepreneurs, those who link up problem definition, solution development and political processes., Methods: We administered a best-worst scaling (BWS) experiment to 89 policy entrepreneurs, asking them to identify the most and the least important criteria on a series of predefined sets. Sets were compiled using a Balance Incomplete Block Design which generated random combinations of all 11 criteria included in the experiment. In turn, those had emerged from a prior set of focus group discussions organized among policy entrepreneurs. Ordered logit models were used to investigate the value of single criteria as well as heterogeneity of preferences., Results: Political commitment was identified as the most important criterion guiding policy decisions on user fee abolition or reduction to the overall sample, but particularly so for more experienced respondents aged over 50 years. International pressure and donor money were identified as least important while equity and institutional capacity were deemed of relatively little importance. Respondents more involved in advising on policy than on formulating policy rated economic issues such as financial sustainability and cost-effectiveness as less important., Conclusions: It is feasible to apply BWS experiments in low-income countries, although whether the technique can be adjusted to elicit preferences among non-literate respondents in these settings is unclear., (© The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.)