[Epidemiology of schistosomiasis in the periurban area of Sotuba, 10 years mass treatment began in Mali]. / Épidémiologie des schistosomoses dans le village périurbain de Sotuba, dix années après la mise à échelle du traitement de masse au Mali.

OBJECTIVE: The objective of this work was to describe the epidemiology of schistosomiasis 10 years after mass administration of praziquantel began in Sotuba, Mali. METHODOLOGY/RESULTS: This observational cross-sectional survey in Sotuba, a periurban village in the Bamako district, took place from July to September 2010 and collected stool and urine samples from residents at least one year old. Kato-Katz (for stool) and urine filtration techniques were used to detect Schistosoma mansoni and S. hæmatobium eggs, respectively. Overall, 335 urine samples and 300 stool samples were examined. The prevalence rate was 5.4% (18/335) for S. hæmatobium and 8.7% (26/300) for S. mansoni. Excretion of these eggs was most frequent in the 6-15 year-old group: 4.8% (16/335) for S. hæmatobium and 7.7% (23/300) for S. mansoni. Snails of the Biomphalaria pfeifferi and Bulinus truncatus species were the intermediate hosts, captured in the fields at water contact points. The principal clinical symptoms reported by participants were abdominal pain 27.2% (61/169) and headaches 23.2% (52/169). CONCLUSION: Despite the implementation of mass drug administration in Mali a decade ago, our results show that schistosomiasis transmission continues in Sotuba. Assessment of the risk factors for this persistent transmission is strongly needed.

[Seasonal variability of intestinal helminths and Schistosoma haematobium in a rural area of the Sahel in Mali]. / Variations saisonnières de l'infestation par les helminthes intestinaux et Schistosoma haematobium en zone rurale sahélienne au Mali

OBJECTIVE: The objective of this study was to determine the prevalence of intestinal helminths and Schistosoma haematobium before and after the rainy season in Pongonon, Mali. METHODS: Volunteers aged one year and above were included. The Kato-Katz method was used to detect eggs and cysts in stool samples, and Wattman filtration to detect S. haematobium eggs in urine samples. Two cross-sectional surveys were conducted in July and November 2007. RESULTS: In July (beginning of the rainy season), 304 volunteers were included; 278 were seen again in November (at the end of the rainy season). We found more intestinal helminths at the end of the rainy season (8.3%) compared to the beginning of the season (2.9%) (P = 0.01). There was no infection with S. haematobium in July but 7.6% in November (P < 0.001). The prevalence of intestinal helminths in children and adults was similar (P > 0.05), but the prevalence of infection with S. haematobium was higher in children aged 6 to 16 years (17/153) than in adults (2/74) (P = 0.02). CONCLUSION: Infections with helminth and S. Haematobium were both more prevalent at the end of the rainy season. Adults were infected as well as children and may constitute potential reservoirs of parasites. Effective control of these parasitic infections requires mass drug administration programs that take place during the seasons of high parasite egg excretion and that also include adult populations in some areas.