Ontario science table shows COVID-19 levels dropping in wastewater, except in the north

Ontario's Science Advisory Table shows COVID-19 levels in wastewater data are steadily declining in all regions except in northern areas of the province.

Dr. Peter Juni, scientific director of the science table, said daily case counts changed late last year when polymerase chain reaction (PCR) testing eligibility was changed to only be offered to those living or working in high-risk settings, such as hospitals or long-term care facilities.

To get a sense of what's happening with COVID-19 cases, scientists are looking to see the concentration of viral material in wastewater samples to gauge if case numbers are rising or falling, said Juni, a professor of medicine and epidemiology at the University of Toronto.

"We saw a peak around the fifth of January in the province of Ontario and now a sustained decrease in concentration," he said.

"This will probably continue on average, for the province, until the next reopening steps."

However, Juni said it's a different story in northern Ontario.

"After a peak around the fifth of January, we had a decrease, and now during the last roughly 10 days or so, we started to see an increase again, which corresponds relatively well to the situation you're seeing in your hospitals."

Juni said that overall, hospitalizations due to COVID-19 are dropping across the province, but in northern Ontario, that's been "less pronounced" than other areas of the province

"It just seems that parts of the north seem to be challenged a bit more, which fits well to what we see when we look at case counts and rates," he said.

"In the province, Northwestern, Porcupine, Thunder Bay, Algoma, and Sudbury and Districts are the places that have the highest rates per 100,000 right now."

Juni said he's not sure why case counts are staying high in parts of northern Ontario.

"What certainly contributes is you came relatively late in the Omicron wave and had initially not much going on," he said.

"What we estimate right now is since the beginning of the Omicron wave, roughly four million people have been infected in Ontario. When I look at the curve … you see that your curve starts to rise later than other parts of the province. It may simply be that there are still less people who contribute to the wall of immunity through infection."

Juni said with restrictions starting to ease on Thursday, everyone needs to take extra precautions, especially people in northern Ontario.