Occurrence and genotype of Giardia cysts isolated from faecal samples of children and dogs and from drinking water samples in an aboriginal area of central Taiwan.

To investigate some aspects of Giardia infection, we performed a cross-sectional study on schoolchildren from an aboriginal area of Nantou County in central Taiwan. Faecal samples from 209 participants and samples of dog faeces and of water from mountain springs found in the area were collected. The participants also filled a questionnaire pertaining to demographic data. Giardia duodenalis was detected in eight of the 209 participants, and all positive isolates belonged to assemblage A. In addition, assemblage A isolates were obtained from four of the 22 water samples, and assemblage C or D isolates were obtained from four of the 42 canine faecal samples. Our results suggest that the risk of Giardia transmission is greater from waterborne than canine transmission in this study area.