Parasitic infections among Karen in Kanchanaburi Province, western Thailand.

The purpose of this study was to determine the rate of intestinal parasitic and malarial infections during a period of low infection among the residents of remote Karen villages in Thailand. Fifty-five males and 64 females, aged 6 months to 70 years, were examined for malaria by thick blood smears using the Giemsa staining technique. Of the 119 subjects, 4 (3.36%) showed positive for malaria with vivax gametocytes. Results suggested that mass screening was not an effective way for diagnosing malaria. Stool samples were examined under a light microscope. The overall intestinal parasitic infection rates were 38.24% in 34 males, and 36.11% in 36 females. These were hookworm (17.14%), Ascaris lumbricoides (7.14%), Trichuris trichiura (1.43%), Strongyloides stercoralis (7.14%), Taenia spp (1.43%), Entamoeba histolytica (1.43%), Entamaeba coli (10.00%) and Giatdia lamblia (1.43%). The highest (55.55%) and lowest (16.66%) rates of infection were observed in age groups 0-5 and over 45, years respectively. In addition, A. lumbricoides and T. trichiura were found more frequently in children, while hookworms was found similarly in every age group. Results showed that the Karen living along the western border of Thailand possessed high rates of intestinal parasitic infections. Strict monitoring and control programs for these parasites should be implemented.