Latest Regina wastewater sampling shows jump in COVID-19 viral load

A University of Regina (U of R) study on the city’s wastewater has revealed a sudden jump in the COVID-19 viral load.

For almost a year, researchers Dr. Nicole Hansmeier and Dr. Tzu-Chiao Chao have been sampling the Queen City’s wastewater and on Aug. 18 they saw an upward trend of not only the viral load but the primary presence of the Delta variant.

“We know the dominant variant in the city is the Delta variant,” Chao said. “But the sudden jump may suggest that it was in one big spreading event. It is possible that say that in the next couple of days, if people are a bit more cautious again and let’s say they wear a mask and socially distance, the values may come down pretty quickly. The values tend to play a dynamic in wastewater.”

Chao explained because of the lower numbers the jump looks dramatic and they need more data to determine a trend.

“Until fairly recently we had very, very low numbers,” Chao said. “The lowest we actually had for pretty much a year or so. But now the latest data, two data points, we see increases which are roughly in line with values we had before the decrease. So at roughly around early May values.”

Collaborating with EPCOR and the City of Regina, the researchers receive samples twice a week. Hansmeier explained they are still waiting on the data for the current week.

The wastewater study has its limits and can only give a snapshot of the current situation, and it cannot predict the future.

“Everyone has to go to the toilet eventually,” Chao said. “We are able to get a rough idea of the total viral load in the community because of the fact that people are producing a virus or would be shedding a virus into the wastewater.”

Hansmeier and Chao are sharing their data with the Saskatchewan Health Authority (SHA).

“(The SHA and health officials) look forward to getting the data because they are correlating the data with the clinical case numbers,” Hansmeier said. “Since they’re also sequencing — identifying what kind of variants medical cases are caused by — we can basically correlate our numbers and our variants that we detect in the city’s sewage system with their clinical cases, and when we see new variants coming up they are quite eager to know what they can expect for the connected cases.”

Saskatoon study of wastewater also sees surge

Saskatoon has the most cases of COVID in the province and that’s reflective in the city’s wastewater.

Researchers at the University of Saskatchewan have also been conducting their own sampling study over the last year. The latest findings show the highest amount of COVID in the wastewater since the beginning of the pandemic.

Samples from Aug. 12 to Aug. 17 showed the wastewater viral load jumped 348 per cent. Aug. 15 and Aug. 17 showed the highest RNA load ever measured in Saskatoon’s wastewater.

Data in the study is updated every Monday afternoon.