As part of a broad epidemiologic survey on health and nutritional status of children living in the City of São Paulo, Brazil, a random sample of under-fives (n = 695) was submitted to stool tests for detection of intestinal parasites. The tests used the sedimentation technique. When the specimens were soft or liquid, direct smear was also utilized. The prevalence of any intestinal parasite was 30.9%. Prevalences of ascaridiasis, giardisis and trichiuriasis were 16.4%, 14.5% and 12.5%, respectively. Lower prevalences were observed for E. histolytica, H. nana and S. stercoralis: 2.0%, 0.9%, and 0.3%, respectively. Hookworm was found in only one child. Schistosoma mansoni was not detected in the sample. Thirteen percent of the children had two or more different parasites and 4.8% three or more. The current prevalences compared to the prevalences observed in the city in 1973/74 show a considerable decline of ascaridiasis and trichiuriasis but not of giardiasis. Frequencies of intestinal parasites according to the age of the child reveal that prevalences tend to increase with age, particularly from the first to the second year of life. The prevalences tend also to increase with the decline of the socioeconomic level: the poorest stratum of the population presents a general prevalence of intestinal parasites nine times greater than the prevalence registered in the richest stratum. The socioeconomic gradient exists also for G. lamblia, but it is considerably lower than that observed for the other intestinal parasites. This fact confirms the more complex epidemiology of giardiasis.
Child health; Health surveys; Intestinal diseases, parasitic; Socioeconomic factors; Age factors