Tuesday, January 11, 2022

ANOTHER CANADIAN FIRST
Omicron was in Nova Scotia wastewater before it was identified in South Africa
Jessica Mundie 
POSTMEDIA
© Provided by National Post A pop-up COVID-19 testing site on the Dalhousie University campus in Halifax on Nov. 23, 2020.

New data from researchers at Dalhousie University show that Omicron was in Nova Scotia wastewater weeks before it was identified by the province — and even before the new COVID-19 variant was reported by South Africa.

Graham Gagnon, professor, and director of the Centre for Water Resource Studies confirmed in an email that: “Our team detected Omicron , retrospectively, in Nova Scotia wastewater in mid-November and will be able to provide further information in the future.”

The first case of Omicron in Nova Scotia was confirmed on Dec. 13, just a few weeks after it was reported in South Africa on Nov. 24.

Gagnon’s team has been testing wastewater from Nova Scotia’s four main treatment plants since December 2020. They have also been testing wastewater from the student residences at Dalhousie’s campus.

This type of testing will become a critical tool in tracking the spread of COVID-19 in the coming months as access to PCR testing across the country is becoming increasingly limited, said Mark Servos, professor and researcher in the biology department at the University of Waterloo. His lab is currently surveilling wastewater in the Peel, York, and Waterloo regions of Ontario.

“As Omicron continues, the wastewater is going to respond by going up or going down and that’s what is going to help inform our policy people,” he said.

Currently, in Ontario, PCR testing is available only for symptomatic high-risk individuals and those who work in high-risk environments. This means it is going to be harder to get an accurate picture of who has COVID, especially because Omicron is so easily transmissible, said Servos.

In wastewater, Servos said they were able to see how fast each variant took to become dominant in the province.

“Alpha took a couple of months to take over, Delta took a month and a half, and Omicron took almost two weeks.”

In Alberta, where PCR testing is also limited, researchers are monitoring wastewater across the province for the spread of COVID-19 and its variants.

Casey Hubert, associate professor in the department of biology at the University of Calgary and one of the leads on a wastewater monitoring project in Calgary, said that wastewater testing has been able to tell researchers what is happening a week before it is reported.

“Wastewater really provides that kind of early warning signal that precedes the case counts,” he said.

Albertans can use a dashboard set up by Hubert’s team to monitor the amount of COVID-19 in the wastewater across the province. This is a helpful tool, said Hubert, because with less testing there is less accurate information being given about how many people may have the virus.

While wastewater testing has been successful in some provinces, not all public health units are seeing the benefits.

In Quebec, where PCR testing is limited to those in high-risk settings and northern and remote communities, Santé Quebec decided to not extend the funding for a project that tested wastewater in the province.

The project, CentrEAU-COVID run by researchers at Polytechnique Montréal and McGill University, tested water in areas around Montreal and Quebec City. The decision to stop funding was made the same week the Omicron variant was detected in the province.

Dominic Frigon, one of the coordinators on the project, said their project was conducted mostly during the third wave of the pandemic in Quebec. In Montreal, the number of cases was not changing drastically per day, said Frigon, which made the wastewater data flat, while in Quebec City the number was going up rapidly and the data reflected this.

“Because this data was fairly new, we had a hard time explaining to public health why this data was useful,” said Frigon.

Without wastewater testing, Frigon said that public health will be missing out on important data that indicates whether cases are rising or declining.

“We would have a better picture of this if we were testing,” he said.

When interpreted properly, and in collaboration with other public health measures like PCR testing, Servos said that wastewater testing can be a useful tool in the short-term and long-term monitoring of the pandemic.

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