Incidence of endemic Opisthorchis viverrini infection in a village in northeast Thailand
Upatham, E.S.; Brockelman, W.Y.; Viyanant, V.; Lee, P.; Kaengraeng, R.; Prayoonwiwat, B.
American Journal of Tropical Medicine and Hygiene 34(5): 903-906
1985
ISSN/ISBN: 0002-9637 PMID: 4037181 Document Number: 247042
Incidence, measured as the proportion of persons whose stools become positive within one year, was studied in endemic Opisthorchis viverrini, the human liver fluke, in a northeastern Thai village over a two-year period. Incidence was higher in males than in females, especially in children under five years of age. It was at least 47% overall in the first year of the study, but declined to below 20% per year in the second. This is attributed to drying of a local water reservoir and decline in availability of infective stages in fish. The fluctuation of incidence is probably due to the large variations in rainfall from year to year. The rate of reversion from positive to negative varied from 2% to 6% per year.