Parasite egg contamination of vegetables from a suburban market in Hanoi, Vietnam.

Helminth egg contamination of vegetables purchased at suburban market in Hanoi, Vietnam was examined. A total of 317 vegetables were examined and 82 (26%) were revealed to be positive for parasite eggs. Of the 15 varieties, 13 were positive except for horseradish and cucumber. Contamination was highest in leafy vegetables (31%), followed by root vegetables (17%) and fruit vegetables (3%). Throughout the survey, five species of parasite eggs were found: Ascaris sp., Trichuris sp., Toxocara sp., Taenia sp. and Ascaridia galli. In the interview with the villagers, 121 (81%) of 149 adult villagers stated that they usually use not only animal feces but also human feces as a fertilizer. Throughout the survey, a total of 453 eggs were recovered. Number of eggs recovered from vegetables was higher in the dry season (355 eggs) than in the rainy season (98 eggs). The study revealed that vegetables purchased at a market in suburban Hanoi (Vietnam) were highly contaminated with parasite eggs excreted by humans and animals. Considering the eating habits of the Vietnamese and the 17% embryonation rate of detected parasites, vegetables seem to play an important role in soil-transmitted helminth infection in this country.