: Lymphedema (LE) is one the most disfiguring chronic manifestations of lymphatic filariasis. Its management relies primarily on limb hygiene and local care. A previous study in Ghana demonstrating a beneficial effect of doxycycline on LE led to the current multicenter trial on the efficacy of doxycycline in filarial LE. A randomized placebo-controlled trial was initiated in two rural health districts in Mali. Patients with LE stages 1–3 were randomized to receive either doxycycline (200 mg/day) or placebo over a 6-week monitored treatment period and were then followed every 6 months for 2 years. Both groups received materials for limb hygiene that was carried out daily for the entire 2-year study. The primary endpoint was lack of progression in LE stage at 24 months. One hundred patients were enrolled in each study arm. The baseline sociodemographic characteristics of each group were largely similar. There was no significant difference at month 24 after treatment initiation in the number of subjects showing progression in LE stage between the two treatment arms (P = 0.5921). Importantly, however, the number of attacks of acute adenolymphangitis (ADLA) was reduced in both arms, but there was no significant difference between the two groups at any follow-up time point (all P >0.23). Doxycycline was well tolerated in those receiving the drug. When added to daily self-administered limb hygiene, a 6-week course of doxycycline (200 mg) was not superior to placebo in increasing the improvement associated with hygiene alone in LE volume, stage, or frequency of ADLA attacks over a 24-month period.

The interpretation of a laboratory test result requires an appropriate reference range established in healthy subjects, and normal ranges may vary by factors such as geographic region, sex, and age. We examined hematological and clinical chemistry parameters in healthy residents at two rural vaccine trial sites: Bancoumana and Doneguebougou in Mali, West Africa. During screening of clinical studies in 2018 and 2019, peripheral blood samples from 1,192 apparently healthy individuals age 6 months to 82 years were analyzed at a laboratory accredited by the College of American Pathologists for a complete blood count, and creatinine and/or alanine aminotransferase levels. Based on manufacturers’ reference range values, which are currently used in Malian clinical laboratories, abnormal values were common in this healthy population. In fact, 30.4% of adult participants had abnormal neutrophil levels and 19.8% had abnormal hemoglobin levels. Differences by sex were observed in those who were older, but not in those younger than 10 years, for several parameters, including hemoglobin, platelet, and absolute neutrophil counts in hematology, and creatinine in biochemistry. The site-specific reference intervals we report can be used in malaria vaccine clinical trials and other interventional studies, as well as in routine clinical care, to identify abnormalities in hematological and biochemical parameters among healthy Malian trial participants.

Background Serosurveillance is an important method to help monitor COVID-19 in the community in Mali. We previously adapted and qualified a two-antigen Enzyme-Linked Immunosorbent Assays for use in local laboratories using venous blood samples (95% CI, 73.9% (51.6–89.8) and 99.4% (97.7–99.9)) respectively as sensitivity and specificity). However, the burden of blood collection set cost can be challenging in resource limited region where alternative source of biological material will facilitate a large scale of COVID19 surveillance. In this study (funded by NIH) we assessed the of dried blood spot (DBS) samples to quantify Sars-Cov-2 antibodies by ELISA using RBD and Spike antigens. Methods Respectively 248, 226 and 391 volunteers were randomly selected from Sotuba (urban), Bancoumana (town) and Doneguebougou (village). Venous blood and DBS samples were collected, tested in parallel to assess concordance and the performances of the DBS samples. During the optimization phase (n=36), a promising concordance was found. This allowed us to analyze 829 additional samples on the Spike antigen. Results We had (31/36) of samples that were COVID-19 seropositive (two category kappa 1.0) in both type of samples, suggesting a strong concordance. Analysis of the 829 samples showed a high correlation (Pearson r = 0.9239 p < 0.0001) with 98% concordance between venous blood ELISA and simplified DBS spike ELISA (kappa = 0.92). As performances, the DBS showed a sensitivity of 99% (95% CI, 98%-99%) and a specificity of 99% (95% CI, 93%-100%). It had 100% (95% CI, 99%-100%) as positive predictive value, 88% (95% CI, 79%-94%) as negative predictive value. Conclusion Overall, DBS elution and testing was comparable to venous blood testing in the Malian population, and this supports it use in large-scale SARS-CoV-2 serosurveillance studies as a valuable alternative to venipuncture. Our perspective is to optimize/adapt DBS serology to other viruses like Zika virus, Ebola virus, Dengue virus, hepatitis viruses.

Malaria transmission in the Sahel persists during the dry season despite low microscopic parasite prevalence, maintaining reservoirs that hinder elimination efforts. Understanding serological markers of Plasmodium falciparum gametocyte exposure may help identify hidden transmission reservoirs during low‑transmission periods. We conducted a cross‑sectional survey in Kéniéroba, Mali, at three time points representing key seasonal periods: December 2024 (end of rainy season), May 2025 (dry season), and August 2025 (rainy season). A total of 356 participants were enrolled across three age groups (5-8, 9-17, and ≥18 yrs). Parasitaemia and gametocytaemia were assessed by microscopy. IgG and IgM responses to clinically isolated late-stage gametocytes were quantified by ELISA, and seropositivity thresholds defined using malaria‑naïve controls. Microscopic P. falciparum infection prevalence remained stable across surveys (~13%), but gametocyte carriage declined from 5.7% in December to ~2% in May and August, whereas gametocyte density was higher in the latter months. IgG/IgM seropositivity exceeded 95% throughout, with IgM peaking in May, consistent with recent antigenic stimulation. Age‑stratified analyses revealed weak but statistically significant associations between antibody levels and gametocyte carriage restricted to children aged 5-8 yrs, while no associations were observed in older children or adults. In conclusion, serological analyses indicate widespread and seasonally variable exposure to P. falciparum in Kéniéroba, with consistently high IgG and IgM responses to gametocytes reflecting intense background malaria exposure and cross‑reactive immunity from asexual stages. Seasonal and age‑stratified patterns identify school‑aged children as an important reservoir sustaining transmission. Although overall correlations with gametocyte carriage were weak, age‑specific associations suggest an age‑dependent relationship between antibody responses and carriage.

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.