Occurrence of Human Norovirus GII and Human Enterovirus in Ontario Source Waters

Abstract

Norovirus and Enterovirus are common human viral pathogens found in watersources. Despite causing gastroenteritis outbreaks, most jurisdictions, including Ontario, do not monitor for enteric viruses in waters. The objective of this thesis was to monitor the presence of human Norovirus and Enterovirus in Ontario source waters intended for drinking. Two untreated source water types (river and ground water) were sampled routinely and following precipitation and snow melt events between January 2015 and April 2016. Physical, chemical, microbiological, and meteorological data were collected, coinciding with sampling events. A modified USEPA Method 1615 was applied to detect and quantify viruses and logistic regression was used to examine relationships between virus presence and environmental parameters. Norovirus was detected in 41% of river water and 33% of groundwater samples. Enterovirus was detected in 18% of river water and 29% of groundwater samples. No correlations between virus detection and environmental parameters were found.