[Seasonal variability of intestinal helminths and Schistosoma haematobium in a rural area of the Sahel in 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.