University of Saskatchewan researchers, who have partnered with the City of Saskatoon and the Saskatchewan Health Authority, have developed an early warning system for COVID-19.

They are doing this by sampling and testing the city’s wastewater for the SARS-CoV-2 virus.

Infected people shed virus traces through their feces often before COVID-19 symptoms are apparent. Using a technique at USask, the team has found they can analyze wastewater samples from Saskatoon’s municipal treatment plant that shows changes to the total amount of virus circulating in the city’s wastewater happen about a week ahead of changes indicated by those case counts you hear every day.

That’s because people getting tested either have symptoms or they have been in contact with someone who has COVID-19. The wastewater picks up on those people who are asymptomic or pre-symptomatic.

USask ecotoxicologist John Giesy thinks they can give health officials at least a week’s notice on changes in the trend.

“Based on the latest data which shows the trend line is going up, I am predicting we will see a rise in cases for the next couple of weeks. We can also predict when outbreaks are declining, which will help planning for pandemic recovery.”

The research team produces data once per week, and then shares it with the CoS which conveys it to the Saskatchewan Health Authority. The team suggest more dedicated funding would allow them to increase the frequency of gathering and analyzing samples which has the potential to predict new case numbers.