"It is not necessary, nor is it recommended that the general public boil their drinking water," says Dr. Fast.

Tom Pearson, Manager of the City's Water Services Division, says, "25 tests have been conducted on the water supply since November 21, 2000, and all of them have been negative for Cryptosporidium. Routine tests of wastewater continue to be negative for this parasite."

Dr. Fast says that there have been no reported cases of Cryptosporidium in Winnipeg residents in the past several months. Physicians have been legally required to report confirmed cases of Cryptosporidium to Manitoba Health since July 1999. Regional Health Authorities across the Province are required to investigate any reported cases.

Since 1994, the City of Winnipeg has regularly tested the water supply for Cryptosporidium at Shoal Lake and at Deacon Reservoir. The results of several tests in November 2000 revealed the presence of low levels of Cryptosporidium at Deacon Reservoir - the first time Reservoir samples have tested positive. In response to the positive results, and as a precautionary measure, severely immunocompromised persons were advised to boil tap water used for drinking and food preparation until further notice. In addition, operational changes in the water supply were undertaken, an enhanced testing program was conducted and there was a detailed investigation into the possible source of the Cryptosporidium. The investigation suggested that the likely source of the Cryptosporidium was unusually heavy rainfall and accompanying local flooding that took place in southeastern Manitoba in November.

Cryptosporidium can cause a diarrheal illness called cryptosporidiosis. Dr. Fast reminds persons with severely weakened immune systems that cryptosporidiosis can be serious or even life threatening for them. A safe and effective treatment for cryptosporidiosis has not been developed. In the fall of 1996, information was released jointly by the City and the Province of Manitoba to make physicians and immunocompromised individuals aware of the risks associated with Cryptosporidium in drinking water. Immune compromised persons were advised to consult with their physicians about taking the precautionary measure of boiling their drinking water. A reminder notice was issued in spring 1997, summer 1999 and late last year in association with the positive results at Deacon Reservoir.