Schistosoma mansoni infection and nutritional status in schoolchildren: a randomized, double-blind trial in northeastern Brazil.

Brazilian schoolchildren with mild- to moderate-intensity schistosome infections (<400 Schistosoma mansoni eggs/g stool) were randomly allocated to a treatment (oxamniquine) or placebo group in a double-blind fashion. Anthropometric measurements were made at baseline, 6 mo, and 1 y for 353 students. At baseline, the groups were not significantly different with respect to nutritional status or selected socioeconomic and biological characteristics, including anthropometric measures. One year later, significant differences were noted only in the nutritional status of boys treated for schistosome infection. Treated boys had greater measurements for weight, triceps skinfold thickness, midarm circumference, arm muscle area, and body mass index than untreated boys. They also showed significant increases over the year in weight, height, midarm circumference, and body mass index. The rates of improvement in weight and height were more accelerated in the first 6 mo after therapy than the last. These results indicate that, at least in boys, chronic S. mansoni infection at any intensity is detrimental to short-term growth and development.