RESUMO
The increasing environmental contamination affects the water quality, and is going to raise the waterborne intestinal infections such as giardiosis. This study determined the prevalence of G.lamblia infection in 1201 persons of Gualeguaychú, Argentina. It was observed the relationship between giardiosis and the detection of G.lamblia in the recreational and drinking water and with homes environmental factors. General rate of infection was 19.7%. The group 2-11 years old was the highest (28.0%). No cysts of G.lamblia were found in drinking water, but recreational water was contaminated. Higher rate of infected persons lived in suburban dwellings with dirt floor, latrine, ground-water and close contact with dogs. It is concluded that to drink water is no risk-infection at present, but it will be if this community continues discharging excretsa into the river because this is the source of water for the habitants.