Intestinal parasitic infections among children of a primary school in Chiang Mai city, northern Thailand.

Fecal samples were examined in 117 children, ranging in ages from 8 to 14, in a primary school in Chiang Mai City, north Thailand. The positive rate of all parasitic infections was 23.9%. Hookworms were the most prevalent parasite (17.1%), followed by Trichuris trichiura (5.1%), Strongyloides stercoralis (3.4%), Entamoeba coli (1.7%), Entamoeba histolytica (0.9%) and Opisthorchis viverrini (0.9%). No Ascaris lumbricoides was found, mainly because of individual treatment with drugs.