Schistosomiasis mansoni in the Dominican Republic; prevalence and intensity in the city of Higuey by coprological and serological methods.

The prevalence and intensity of infection with Schistosoma mansoni were determined in a sample of the population of the city of Higuey, Dominican Republic. The quantitative formol-ether stool sedimentation technique of Ritchie, as modified by Knight et al., was performed on stools from 1,025 (65.5%) of 1,563 individuals greater than 1 year old. The highest prevalence rates (21.4%) were observed in women 25-29 years old and in men 15-19 years old (20%). The maximum fecal egg count was in the 15- to 19-year age group, with a geometric mean of 30 eggs/g feces among men and 15.8 eggs/g feces in men and women. The overall prevalence of S. mansoni-infection was 11.8% with a geometric mean excretion of 8.8 eggs/g feces. In addition, the circumoval precipitin test was carried out on 639 sera and 110 (17.2%) were positive, increasing the prevalence in all age groups. Examination of Biomphalaria glabrata snails collected in early 1986 showed 7.8% to be positive for S. mansoni cercariae. Despite the moderate prevalence rates and the low intensity of infection among the human population, we consider Higuey to be an important focus of schistosomiasis in the Dominican Republic. The sensitive coprological and serodiagnostic techniques we employed have helped to identify the age- and sex-specific groups most deserving of treatment in order to reduce transmission of infection and disease prevalence.