U of S professor believes COVID-19 cases will soon drop in Sask. cities

University of Saskatchewan toxicologist John Giesy says recent wastewater data shows new COVID-19 cases could be dropping sharply in the next few weeks.

According to a study released Monday by the Global Institute for Water Security, samples taken from wastewater plants in Saskatoon, North Battleford and Prince Albert showed a decrease in COVID-19 viral load.

According to the study from the University of Saskatchewan, viral load in Saskatoon's study had dropped by 39.3 per cent compared to the week before, while Prince Albert's viral load had decreased by 58.2 per cent.

North Battleford also saw a decrease of 8.1 per cent.

The samples were all taken last week and can predict a rise or fall in cases from seven to 10 days from the time they are taken.

Giesy, who works with the institute, believes that cases will trend downwards in the short term, although he believes it will take longer for hospitalizations to go back down.

In an interview with CBC's David Shield, Giesy talked about studying the trends and the uncertain future of COVID-19 in Saskatchewan.

The conversation has been edited for length and clarity.

David Shield: What does the current outlook look like for COVID-19 across the province?

John Giesy: My prediction, based on our trend lines and knowledge about how this variant is acting, is that we should be close to back down to background by the first or second week of February. So, you know, it's good news. The trend line is down and we will get there. But the uncertainty is if another variant pops up, that would help [the virus] avoid our immune system, either from vaccination or from infection.

Walk me through what COVID-19 looked like over the last several months.

Back in the first week of December, we were really at a non-detect level. We couldn't find any of the virus in wastewater. Christmas came and we saw a huge spike, which we predicted would happen. Then right after that, things started coming back down. Then kids went back to school, we saw another spike up, and now we're on the downside of that. 

What about hospitalization rates? 

It will take longer for hospitalizations and particularly the ICU numbers to come down. Once you end up in the ICU, you could be there six or eight weeks, so that takes longer to recover. So right now, the concern of all the regulators and the epidemiologists is just the pressure on the health-care system, just the vast number of people that are testing positive and are ill, including the front line health-care workers. That's where things are getting hit pretty hard.

How do the wastewater numbers compare to what's being released by the provincial government?

It's hard to relate our numbers to what the province is reporting for new cases. People just aren't getting tested. So now the province really is relying more on our data to look at the future. 

I'm scheduled to give a presentation to the Saskatchewan Health Authority in their weekly meeting to talk about how they can integrate our data better into their planning. With clinical testing breaking down, if you tested positive or I tested positive, now the guidance is just stay at home, wait it out and don't go get [PCR] tested. So right now, what they were relying on to make policy decisions is breaking down. So they want to know, how can we use our numbers?

What about the prospect of a new variant?

Everyone's worrying about a new variant coming on the scene, and I can't predict that from the data that I collect. We do sequencing, so we're looking for those new variants, but I can't predict when one might occur.

Looking forward, what could be done to slow the spread of COVID-19?

As you know, we don't really have any regulations in place. What would likely change the trend line would be if suddenly there were some restrictions put into place. When people are talking about flattening the curve, what that does is it takes down the spike and spreads it out longer into the future. So if something like [new restrictions] were to occur, we would probably go down more quickly.