Waste water sampling for COVID to continue

By COLLIN GALLANT on December 9, 2021.

cgallant@medicinehatnews.com@CollinGallant

A largely unheralded effort to detect levels of COVID-19 in Medicine Hat will continue in a more formal relationship between the city’s sewage plant, the province and two universities.

Since the spring of 2020, samples of the city’s waste water have been collected and analyzed for levels of the virus. That raw data doesn’t isolate or locate new cases, but represents a 100% sample size.

That can then be used to determine the level of infections in the entire area and can be used to predict trends.

“It’s a very good idea,” said Boyd Mostoway, operations manger for Medicine Hat Water and Power. “We’ve been doing it for about 18 months and we chose to participate early on. They have now expanded the project.”

Health officials are saying high-level surveillance may become more valuable. As vaccination levels rise, symptoms lessen, and fewer positive cases may be diagnosed.

“We expect over time to see more asymptomatic or minimally symptomatic infections – accordingly, patients may not get COVID tested and would go unrecognized,” said Dr. Michael Parkins, a project leader based at the Cumming School of Medicine at the U of C, in a release.

“Wastewater testing doesn’t discriminate and is the best way of comprehensively monitoring municipal COVID-19 case rates.”

On Wednesday the province announced $3.4 million in new funding to continue the study with analysis of sewage from 25 towns and cities with research done at the universities of Calgary and Alberta.

Results are publicly available on the website of the Centre for Health Infomatics at the University of Calgary.

The chart for Medicine Hat shows a large spike in material detected beginning in late July, about one week before a fourth wave in the city sent diagnosed active case numbers from single digits to more than 500 in August.

“Wastewater data allows us to identify and track the amount of COVID-19 cases in an identified area, even if they haven’t been clinically diagnosed,” said Parkins.

Provincial funds will pay for researchers to analyze samples at municipal waste water treatment facilities, which collectively serve about three quarters of Albertans, or about 3.4 million residents.

In southern Alberta, Medicine Hat, Lethbridge, High River and Calgary are involved, with others expected to join.

The key factor is that elements of the virus will be detectable in urine and feces before a person is symptomatic.

Testing the general system does not isolate cases, but levels can indicate to health-care professionals that higher case numbers in a community could be coming.

Epcor in Edmonton provides onsite testing for some seniors facilities to provide alert that there is a positive case and precautions can be taken.

That level of analysis is not in place in Medicine Hat, but could be considered, said Mostoway.

“It’s gone thinking that it (the sample) would be a lagging indicator to a predictive indicator,” he said, adding there is no cost to the city to participate.

The city’s waste water treatment facility tests incoming effluent on an ongoing daily basis anyway to determine how to best treat the water before its eventual release back into the South Saskatchewan River.

The city doesn’t have the facilities to isolate viral content, however.

The local contribution to the program involves filling two additional sample bottles three times each week and sending them away by courier.