Intestinal parasitosis in an urban pediatric clinic population.

Three hundred twenty-one pediatric patients were prospectively screened for intestinal parasites. Of the stool specimens, 49.5% were positive for ova or parasites. Positive stool specimens were significantly correlated with recent travel to Mexico by the patient or a household member. The incidence rate for Giardia lamblia was 20%, and it was 5% for both Ascaris and Trichuris. Hymenolepis nana was the fourth most common parasite, with a rate of 4%. No identifiable clinical, laboratory, or other demographic predictors of parasitic infestation were found. Giardia seems to be rapidly increasing in prevalence and may be the most frequently isolated parasite in the southern United States.