Helminth Infections in Some Areas of Thailand where Strongyloides is Prevalent

Abstract In April 2006, parasitic infections were sur veyed in Nakraseng Village, Amphoe Tha Li, Loei Province, Thailand. A total of 440 s tool s amples were examined by Kato’s thick smear and modified Harada-Mori cu lture techniques. Overall helminth prevalence by both methods was 35%; the most prevalent was Strongyloides stercoralis (17.7%), followed by Opisthorchis viverrini (15.7%). Hookworm is seldom found in this area (2.3%). This indicates that mass treatment for S. stercoralis and O. viverrini transmission in some areas would prove ineffective in parasitic control. Soil-transmitted helminths were found to be higher in males than females (P < 0.05). Higher annual incomes (10,000 Baht) correlated with a lower risk of infection (P < 0.05). People who walked barefoot had a higher risk of infection than those who wore shoes (P < 0.05). Flatworms were found by Kato’s thick s mear. O. viverrini showed the highest prevalence of 15.7%, followed by minute intestinal fluke (5.2%) and Taenia spp (2%). The efficacy of detecting S. stercoralis by modified Harada-Mori cultur etechnique, at 96.3%, was far higher than Kato’s thick s mear (6.2%). It is r ecommended that, in epidemic areas for soil-transmitted helminths, the modified Harada-Mori cultur etechnique be us ed as a s econdary precaution to detect infections. Keywords : parasitic infections, Kato’s thick smear, modified Harada-Mori culture technique