RESUMEN
Intestinal helminths are a very common but still rather unrecognized public health problem. An attempt was undertaken to control the three important parasites, ie Ascaris, Trichuris and hookworm. Two villages in Vientiane Province in Lao PDR were selected, one as an intervention and the other as control village. Intervention measures started by providing mass treatment against Ascaris, Trichuris, hookworm and other intestinal parasitic infections in both villages. Health education and other intervention measures were implemented in the intervention village, which significantly influenced the re-infection rates in this village. These achievements were not due to an improvement of the availability of toilets or personal hygiene alone but more to the villagers' improved understanding of the route of the parasitic infections. It was concluded that intervention methods should be directed more towards particular age groups. Particular attention should be paid to control parasitic infections among females.