[Intestinal helminthiasis among school children: preliminary results of a prospective study in Agboville in Southern Côte d'Ivoire].

Intestinal helminthiasis affects the health and academic performance of children in developing countries. To highlight a few socio-economic factors that impact the presence and upholding of intestinal helminthiasis, a cohort study was performed from February to June 2001. This study took place in Agboville in Southern Côte d'Ivoire on 363 children, under the age of 15, regularly enrolled in school and selected by two-step clustered sampling. After the survey was completed, their stools were examined using 3 methods: direct exam, Kato's technique, and Graham's anal scotch-test. Infected students received an appropriate anti-helminthic treatment. After performing a test two weeks later, a new sample of 348 parasite-free children was made up and re-examined after three months, through the aforementioned techniques. In this sample, we assumed that students who were infested in the initial exam were "exposed", while those who were not infested in the first place were deemed to be "not exposed". The results showed that 135 students out of the 360 admitted for the first exam were infested; or a 37.5% of intestinal helminthiasis prevalence (IC95%=30.5-45). The prevalent parasite species were Necator americanus (15%), Trichuris trichiura (13.6%), Schistosoma mansoni (10%). Twenty-eight per cent of 135 infested students were infected by more than one parasite. After three months, the incidence rate of intestinal helminthiasis calculated out of the remaining 336 students was 7.7% (IC95%=4.4-13.1). The likelihood of re-infestation amounted to 3.4 (IC95%=1.5-7.3). The pattern of re-infestation rates according to socio-economic factors differed from that of infested prevalence. The prevalent parasites in re-infested patients were Trichuris trichiura (16.3%), Schistosoma mansoni (12.5%). All intestinal nematodes and Schistosoma mansoni were observed. The most frequent parasites species where those transmitted cutaneously. The high re-infestation rate suggests that intestinal helminthiasis in this region affects roughly the same children. These results show the necessity to continue our investigations in order to highlight essential hygienic factors in our long-term fight against intestinal helminthiasis.