ABSTRACT
The prevalence of the Giardia duodenalis and Cryptosporidium parvum infections were studied in children 2-60 months old (n = 310) grouped to sex and age, enrolled in 8 day-care centers. Giardiasis was found in 42 (13.5 per cent) of the children and, was most frequent in the age group corresponding to 19-24 months old although children at the first six months of life also presented positive faecal samples. Statistical analysis indicated no association between sex (p > 0.05) and prevalence for Giardia infection. C. parvum was detected in 20 (6.4 per cent) of the children. Children seven to twelve months old showed the greatest prevalence of this parasite. There were not oocysts in the stools from the children 25-30 months and from those older than 36 months. Oocytes were detected in 4 children from the 0-6 months old group. There was no significative difference on sex (p = 0.09) and day-care-facility (p = 0.068) for C. parvum infection while age was associated with infection (p = 0.004). Epidemiological aspects were studied by familiar inquiry, by parasitological examinations of stools from the contact-members of each case and from animals present at the residence. Prevalence for C. parvum was higher when at least one of the parents was a professional in the Human Health Centers (73.6 per cent positives), when there was report of concomitant disease (52.6 per cent positives) and when diarrhoea was the main symptom at the collection of the faecal specimens (78.9 per cent positives). Faecal examinations of the domestic animals were negatives for these two parasites.