Epidemiology of Cyclospora cayetanensis and other intestinal parasites in a community in Haiti.

We conducted an exploratory investigation in a community in Haiti to determine the prevalence of Cyclospora cayetanensis infection and to identify potential risk factors for C. cayetanensis infection. In 2001, two cross-sectional stool surveys and a nested case-control study were conducted. In 2002, a follow-up cross-sectional stool survey was conducted among children < or =10 years of age. Stool specimens from study participants and water samples from their wells were examined for Cyclospora and other intestinal parasites. In stools, the prevalence of infection with Cyclospora in persons of all ages decreased from 12% (20 of 167 persons) in February 2001 to 1.1% (4 of 352 persons) in April 2001, a 90.8% decrease. For children < or =10 years of age, the prevalence rates were 22.5% (16 of 71 children) in February 2001, 3.0% (4 of 135 children) in April 2001, and 2.5% (2 of 81 children) in January 2002. Use of the water from the artesian well in the northern region of the community versus the one in the south was the only risk factor associated with Cyclospora infection in multivariate analyses (odds ratio, 18.5; 95% confidence interval, 2.4 to 143.1). The water sample from one of the nine wells or water sources tested (one sample per source) in January 2001, shortly before the investigation began, was positive for Cyclospora by UV fluorescence microscopy and PCR. None of the water samples from the 46 wells or water sources tested during the investigation (one sample per source per testing period, including the artesian wells) were positive for Cyclospora. Further studies are needed to assess the role of water as a possible risk factor for Cyclospora infection in Haiti and other developing countries.