Prevalence of intestinal parasites and association with symptoms in Southeast Asian refugees.

We prospectively evaluated 201 Southeast Asian refugees in a primary care clinic for intestinal parasites and their association with gastrointestinal symptoms. Patients completed a standardized screening questionnaire which elicited information on demographic factors and eight gastrointestinal symptoms, and stools were collected for ova and parasite examination. Although 89% had been living in the U.S.A. for more than 1 year, intestinal parasites were found in 37 (18%) patients and pathogenic parasites in 23 (11%). Among these 37 patients with intestinal parasites, seven (19%) had multiple parasites. Seven pathogenic and four nonpathogenic species were identified. Hookworm was most prevalent (4.5%), followed by Strongyloides stercoralis (2.5%) and Clonorchis sinensis (2%). Cambodians had the highest prevalence (11%) and Vietnamese and highland Laotians the lowest (0%). Intestinal parasitosis was not associated with gender or duration of residence in the U.S.A. Individual symptoms had a low positive predictive value for the presence of pathogenic parasites. This suggests that even years after immigration a substantial number of Southeast Asian refugees may benefit from screening and treatment for intestinal parasites.