Epidemiology of giardiasis and genotypic characterization of Giardia duodenalis in preschool children of a rural community, central Thailand.

A cross-sectional study was conducted to determine the prevalence and risk factors of Giardia duodenalis infection in 189 preschool children at Sanamchaiket District, Chachoengsao Province, central Thailand in February 2007. Stool specimens were examined for the presence of Giardia using simple wet preparation and PBS-ethyl acetate concentration technique. The prevalence of G. duodenalis in preschool children was 5.8%. Using PCR-RFLP analysis of the glutamate dehydrogenase gene (gdh), genotypes of G. duodenalis revealed assemblage AII (3, 30.0%), BIII (1, 10.0%), and BIV (6, 60.0%). Using multivariate analysis, children who kept cat(s) at home were at 5.1 times (95% CI; 1.3- 20.3) greater risk of acquiring giardiasis. This study possibly represents the information supporting the potential zoonotic transmission of G. duodenalis between cats and preschool children. Unfortunately, in this study, we did not determine G. duodenalis infection in cats, so further studies in cats should be performed to confirm this postulation.