Abstract
Four hundred and six soil samples collected from five schoolyards in Mai Trung Commune, Bac Giang Province, Northern Vietnam, from 2005 to 2007 were examined for helminth eggs using a sucrose centrifugal flotation method. The soils around latrines was found to be heavily contaminated with Ascaris sp. eggs. The contamination rate of Ascaris sp . eggs at each school and prevalence of ascariasis among the school children showed a positive correlation (P<0.05). This indicated that examination of soil from the area around latrines for Ascaris sp. eggs is a useful method to estimate the prevalence of ascariasis among school children.