DETECTION OF TOXOPLASMA-GONDII OOCYSTS IN DRINKING-WATER

The world's largest outbreak of waterborne toxoplasmosis occurred in a municipality in the western Canadian province of British Columbia. Wh en drinking water emerged as a passible source of infection during the outbreak investigation, a laboratory method was needed to attempt det ection of the parasite, Toxoplasma gondii. The method developed was ba sed on the current U.S. Environmental Protection Agency method for det ection of Cryptosporidium oocysts. Collection of large-volume drinking water samples and cartridge filter processing were unchanged, althoug h identification of Toxoplasma oocysts in the filter retentate was car ried out by using a previously described rodent model. Validation of t he method developed was tested by using oocysts from a well-characteri zed Toxoplasma strain.