Dolo Mathias

The widespread circulation of the Anopheles vector is observed during the rainy season and clearly decreases during the dry season, when only a few mosquitoes are able to survive. This study aimed to identify the major species sustaining continued malaria transmission across seasons. This cross-sectional study was conducted in a malaria-endemic area. Mosquitoes were captured in Faladie using pyrethroid spray catches during rainy and dry seasons. The collected mosquitoes were identified using morphological keys, combined with molecular techniques such as PCR-RFLP (IGS regions) for Anopheles (An.) gambiae s.l. identification. Plasmodium spp. positivity in each mosquito was characterized by qPCR using parasite 18 S genes. A total of 1082 and 1705 mosquitoes were captured inside the same houses in the rainy and dry seasons, respectively. In the rainy season, 454 (41.9%) were Anopheles, 624 (57.7%) Culex and 4 (0.4%) Aedes. During the dry season, 65 (3.81%) mosquitoes were Anopheles, while 1,640 (96.19%) were Culex. Morphologically, the anopheline population consisted of 100% An. gambiae s.l. The Anopheles species diversity in the rainy season comprised the sister taxa, An. gambiae s.s. and An. Coluzzii, followed by an An. gambiae/An. coluzzii hybrid and An. arabiensis. However, An. coluzzii was found as the only vector across the rainy and dry seasons that sustained malaria transmission. Plasmodium falciparum infection rates were 9.7% and 1.7%, respectively, for the rainy and dry seasons. An. coluzzii species can survive both the dry and the rainy seasons and sustain malaria through cross-seasonal transmission. This highlights the importance of tackling An. coluzzii species and residual malaria transmission to eradicate the disease in endemic areas.

Background: Extreme rainfall caused severe flooding in Kidal, northern Mali, in 2024, raising concerns about the outbreak of malaria associated with climate change. The objective of this study was to describe this epidemic and the response implemented by national and regional authorities. Methods: A historical cohort study was conducted in the Kidal region, covering the entire population. Weekly malaria case data recorded by the national health system between May 2024 and February 2025 were analyzed in conjunction with precipitation data from the Tropical Rainfall Measuring Mission (TRMM, spatial resolution: 0.25°). The interventions included seasonal malaria chemoprevention (SMC), extended to children under 15 years of age, and deployment of mobile health teams in remote areas. The effect of these interventions on malaria cases per 1000 person-weeks was estimated using Generalized Additive models (GAM) applied to interrupted time series, taking rainfall into account. In addition, the spatial distribution of the population at risk was estimated using WorldPop population data. Results: Rainfall began in week 25 and continued for 15 weeks. The malaria epidemic began in week 30, peaked in week 39 with 1,014 cases, and lasted for 28 weeks, with 1.688 (95% CI 1.687–1.690) cases per 1000 person-weeks. Incidence was highest among children under five. The interventions implemented, using extended SMC and mobile health teams, led respectively to a significant reduction in morbidity (respective Standardized Incidence Ratios (SIRs) of 0.50; 95% CI 0.33–0.75 and SIRs = 0.48; 95% CI 0.28–0.82). Conclusion: Malaria outbreaks associated with flooding are becoming increasingly frequent in the context of extreme weather conditions. These situations pose a major challenge for malaria control programs and highlight the need to strengthen surveillance systems. The implementation of weather-based preparedness strategies is essential, including expanding preventive treatment coverage (SMC), deploying mobile health teams, and pre-positioning essential inputs.

Context: During the 2024 rainy season, extreme rainfall events caused flooding in Mali, leading to an outbreak of malaria in the Kidal region of northern Mali. The aim of this study was to describe this epidemic and the response implemented by the national and regional authorities. Methods: Weekly rainfall data (0.25° resolution) from TRMM and malaria cases from national health system. Data on SMCs and mobile clinics come from the national malaria control program. Malaria incidence and rainfall trends were analyzed, with the epidemic described according to severity and age group. The effects of the intervention were assessed using interrupted time series with a generalized additive model. Results: Rainfall began in week 25 (June) and lasted 15 weeks, averaging 3.86 mm/day (CI95: 3.23–4.57). The malaria epidemic began in week 30, peaked at 1,014 cases in week 39, and lasted 28 weeks (incidence: 1.688/1,000 person-weeks; CI95: 1.687–1.690). The [0-11] months and [1-4] years age groups were the most affected, with respective incidences of 1.48 and 0.97 per 1000 person-weeks for severe cases, and 5.04 and 2.35 per 1000 person-weeks for uncomplicated cases. Two interventions were implemented: i) 2 SMC campaigns among children aged 0 to 4 years for the first round, and 0 to 10 years for the second round, during weeks 31 (July) and 41 (October) respectively (6,236 and 27,334 children respectively); ii) mobile teams deployed from week 34 (August) to 39 (September) in remote areas and Internally Displaced People (IDP) sites, with 35 members in addition to the 36 community health workers. These interventions significantly reduced morbidity, with respective SIRs of 0.5 CI95[0.33; 0.75] (p=0.002) and 0.48 CI95[0.28; 0.82] for SMC and mobile teams. Conclusion: Climate change is increasing extreme weather events like floods, altering malaria risk in unstable areas such as northern Mali. Preparedness should include reinforcing community health workers, ensuring adequate diagnostic and treatment stocks, and deploying targeted mobile teams.

Background – Mali was one of the first countries in sub-Saharan Africa to initiate a National Schistosomiasis Control Programme (NSCP) in 1982. The WHO's 2021-30 roadmap sets out criteria for eliminating and controlling schistosomiasis as a public health problem. Our study aimed to assess the impact of annual Mass Drug Distribution (MDD) with praziquantel (PZQ) among school-age children in the sentinel sites (SS) of the NSCP. Methods –The study took place at twelve SS in Kayes and Koulikoro regions. Two-round observational cross-sectional studies were carried out in December 2014-2015 and in April 2018 after four to five years of annually MDD. Overall, 2442 schoolchildren aged 7 to 14 were successfully examined. The urine filtration and Kato-Katz method were used for determining Schistosoma haematobium and S. mansoni eggs, respectively. Results –Of the twelve SS treated from 2014-2015, one has achieved the criterion of elimination of S. haematobium as a public health problem (prevalence of heavy intensity infection PHI < 1%) (ie, ≥50 S. haematobium eggs per 10 mL of urine or ≥400 S. mansoni eggs per g of stool), four met the morbidity control criterion (PHI< 5%) while two sites remained confined below the morbidity control criterion (PHI>5%). Five SS had no heavy intensity infection. The prevalence of S. mansoni was less than 1%. Conclusion –The impact evaluation of MDD with praziquantel in the SS of NSCP highlights that MDD has significantly reduced the PHI of schistosomiasis. However, the high prevalence of schistosomiasis or its increase in some sites requires in-depth studies.

Introduction: Despite the implementation of control strategies at the national scale, the malaria burden remains high in Mali, with more than 2.8 million cases reported in 2019. In this context, a new approach is needed, which accounts for the spatio-temporal variability of malaria transmission at the local scale. This study aimed to describe the spatio-temporal variability of malaria incidence and the associated meteorological and environmental factors in the health district of Kati, Mali. Methods: Daily malaria cases were collected from the consultation records of the 35 health areas of Kati’s health district, for the period 2015–2019. Data on rainfall, relative humidity, temperature, wind speed, the normalized difference vegetation index, air pressure, and land use–land cover were extracted from open-access remote sensing sources, while data on the Niger River’s height and flow were obtained from the National Department of Hydraulics. To reduce the dimension and account for collinearity, strongly correlated meteorological and environmental variables were combined into synthetic indicators (SI), using a principal component analysis. A generalized additive model was built to determine the lag and the relationship between the main SIs and malaria incidence. The transmission periods were determined using a change-point analysis. High-risk clusters (hotspots) were detected using the SatScan method and were ranked according to risk level, using a classification and regression tree analysis. Results: The peak of the malaria incidence generally occurred in October. Peak incidence decreased from 60 cases per 1000 person–weeks in 2015, to 27 cases per 1000 person–weeks in 2019. The relationship between the first SI (river flow and height, relative humidity, and rainfall) and malaria incidence was positive and almost linear. A non-linear relationship was found between the second SI (air pressure and temperature) and malaria incidence. Two transmission periods were determined per year: a low transmission period from January to July—corresponding to a persisting transmission during the dry season—and a high transmission period from July to December. The spatial distribution of malaria hotspots varied according to the transmission period. Discussion: Our study confirmed the important variability of malaria incidence and found malaria transmission to be associated with several meteorological and environmental factors in the Kati district. The persistence of malaria during the dry season and the spatio-temporal variability of malaria hotspots reinforce the need for innovative and targeted strategies.

Background: Uncorrected refractive errors (URE) are a serious public health problem by their magnitude, the multiple consequences they result in, but also by the inability of the countries of French-speaking Sub-Saharan Africa (FSSA) to meet the needs of the population. Governance problems, associated with human resources problems, financing problems for care, infrastructure and consumables, led us to initiate this study, the objective of which is to analyze the situation of UREs in FSSA with the stakeholders involved in the eye health system. Materials and Methods: We carried out a cross-sectional survey of eye health actors and stakeholders in all of the French-speaking Sub-Saharan Africa countries from March 1st to August 31st, 2020. An online questionnaire was developed and translated into French, and then sent to the targeted eye health stakeholders involved in eye health. The survey and data collection were carried out in two phases: first by collecting information from the eye health officials of the countries which then enabled us to reach all the other actors in the country. Data were entered directly into SPSS 20 software followed by cleaning prior to analysis and presented as percent, mean or median, and standard deviation. Result: A total of 500 questionnaires were sent to the various actors involved in eye health in the 21 countries of French-speaking Sub-Saharan Africa. The number of people who opened the questionnaire is 215, of which 151 have completed at least one question. Eye health policy documents existed in countries according to 95% of respondents. In the words of 76.6%, 54.6% and 85.2% of the participants respectively, the mechanisms for describing the tasks of the agents, for reporting to the actors and for collecting data existed. Also, according to respectively 61.5%, 58.8 % and 61.3% of respondents, the following are not effective: existence of documents of standards and procedures, specific allocation of eye health in the budget of the Ministry of Health and the obligation of continuous training. Conclusion: Although policy documents that comply with standards do exist in the French-speaking region of sub-Saharan Africa, several challenges remain to be taken up; in particular, the involvement of all stakeholders of the health system, and the strengthening in the areas of governance, financial and human resources, as well as the information and supply system for materials and consumables, hence the need to initiate more targeted research activities.

Malaria transmission largely depends on environmental, climatic, and hydrological conditions. In Mali, malaria epidemiological patterns are nested within three ecological zones. This study aimed at assessing the relationship between those conditions and the incidence of malaria in Dangassa and Koila, Mali. Malaria data was collected through passive case detection at community health facilities of each study site from June 2015 to January 2017. Climate and environmental data were obtained over the same time period from the Goddard Earth Sciences (Giovanni) platform and hydrological data from Mali hydraulic services. A generalized additive model was used to determine the lagged time between each principal component analysis derived component and the incidence of malaria cases, and also used to analyze the relationship between malaria and the lagged components in a multivariate approach. Malaria transmission patterns were bimodal at both sites, but peak and lull periods were longer lasting for Koila study site. Temperatures were associated with malaria incidence in both sites. In Dangassa, the wind speed (p = 0.005) and river heights (p = 0.010) contributed to increasing malaria incidence, in contrast to Koila, where it was humidity (p < 0.001) and vegetation (p = 0.004). The relationships between environmental factors and malaria incidence differed between the two settings, implying different malaria dynamics and adjustments in the conception and plan of interventions.