This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Roach, P D Articles by Wallis, P M Search for Related Content PubMed PubMed Citation Articles by Roach, P D Articles by Wallis, P M Agricola Articles by Roach, P D Articles by Wallis, P M

 Previous Article  |  Next Article 

Appl Environ Microbiol. 1993 January; 59(1): 67-73

Waterborne Giardia cysts and Cryptosporidium oocysts in the Yukon, Canada.

Meriones Research, Calgary, Alberta, Canada.

ABSTRACT

Several outbreaks of waterborne giardiasis have occurred in southern Canada, but nothing has been reported from the Canadian North. The objective of this study was to collect information relevant to waterborne giardiasis and cryptosporidiosis in the Yukon including epidemiological data and analyses of water, sewage, and animal fecal samples. Remote, pristine water samples were found to be contaminated with Giardia cysts (7 of 22 or 32%) but not with Cryptosporidium oocysts. Giardia cysts were found in 21% (13 of 61) of animal scats, but no Cryptosporidium oocysts were observed (small sample size). Whitehorse's drinking water was episodically contaminated with Giardia cysts (7 of 42 or 17%) and Cryptosporidium oocysts (2 of 42 or 5%). Neither were found in Dawson City's water supply. The only water treatment in the Yukon is chlorination, but contact times and free chlorine residuals are often too low to provide adequate protection by disinfection. Raw sewage samples from the five largest population centers in the Yukon contained 26 to 3,022 Giardia cysts and 0 to 74 Cryptosporidium oocysts per liter. Treated sewage from Whitehorse contained fewer Giardia cysts but more Cryptosporidium oocysts on average. Both were detected in Lake Laberge, downstream of Whitehorse, which has a history of fecal coliform contamination. Daily monitoring of raw sewage from the suburbs of Whitehorse showed a summertime peak of Giardia cysts and occasional Cryptosporidium oocysts after springtime contamination of drinking water. Despite this evidence, epidemiological data for the Yukon showed an endemic infection rate of only 0.1% for giardiasis (cryptosporidiosis is not notifiable).(ABSTRACT TRUNCATED AT 250 WORDS)

This article has been cited by other articles:

• Robertson, L. J., Hermansen, L., Gjerde, B. K. (2006). Occurrence of Cryptosporidium Oocysts and Giardia Cysts in Sewage in Norway. Appl. Environ. Microbiol. 72: 5297-5303 [Abstract] [Full Text]  
• Ono, K., Tsuji, H., Rai, S. K., Yamamoto, A., Masuda, K., Endo, T., Hotta, H., Kawamura, T., Uga, S. (2001). Contamination of River Water by Cryptosporidium parvum Oocysts in Western Japan. Appl. Environ. Microbiol. 67: 3832-3836 [Abstract] [Full Text]