[Annual frequency of Cryptosporidium parvum infections in children and adult outpatients, and adults infected by HIV].

We report the analysis of 4892 parasitological stool samples coming from outpatients and patients of a nutritional recuperation center of north Santiago. Cryptosporidium parvum was detected in 21 samples (0.4%). The protozoan was detected in 6 of 1203 samples from children of less than 2 years old, 3 of 1.727 samples from children between 6 and 15 years, none of 776 samples from healthy adults and 2 of 13 samples from HIV infected patients. Nine of 97 children of less than 2 years old, hospitalized in the nutritional recuperation center, were infected with Cryptosporidium; this frequency was significantly higher than that of outpatients of the same age. Most infections were detected from May to August, a rainy and mildly cold period. It is concluded that Cryptosporidium infections are infrequent in healthy outpatients and that its prevalence increased in hospitalized children and HIV infected adults.