Intestinal parasites in southeast Asian refugees two years after immigration.

We collected stool specimens from 2,520 Southeast Asian refugees who had resided in the United States for an average of 2.1 years. More than half reported receiving prior treatment of parasites. At least one parasite was discovered in 32%, and multiple parasites were found in 8% of patients. Hookworm, Giardia, Strongyloides, and Hymenolepis nana were most commonly found. In comparison to studies done at the time of immigration, all parasites had decreased in frequency, but Giardia, hookworm, and H nana remain common. Although initial screening efforts may have failed to identify substantial numbers of infected refugees, poor compliance with treatment may also explain the persistence of intestinal parasites in our patients. The continued presence of Giardia and H nana, especially among children, may be explained by person-to-person transmission or autoinfection.