Province mulls COVID-19 wastewater monitoring to track spread, provide early detection

·7 min read
Wastewater monitoring for COVID-19 can give officials an early indication of viral trends. (Submitted by Graham Gagnon - image credit)
Wastewater monitoring for COVID-19 can give officials an early indication of viral trends. (Submitted by Graham Gagnon - image credit)

The government of New Brunswick is looking into expanding wastewater monitoring in the province to provide a clearer picture of COVID-19 transmission and early detection of COVID activity.

Right now, only the City of Moncton collects wastewater samples to monitor viral levels as part of a research project at Dalhousie University. The data is shared with Public Health.

"The government of New Brunswick's wastewater surveillance working group is currently working to assess the feasibility of expanding the pilot project that was conducted in Moncton," said Department of Health spokesperson Bruce Macfarlane.

Some provinces have been using wastewater monitoring to project COVID-19 trends since last year, when new cases data became less reliable due to restricted PCR testing. Ontario says it's facing a "tidal wave" of more than 100,000 new COVID-19 cases per day, based on the amount of the novel coronavirus found in its wastewater.

"The government of New Brunswick is working with Dalhousie University in a wastewater monitoring pilot project," Macfarlane said in an emailed statement.

"At this time, usability for our own population and sewage system is not as clearly defined as it is for some of the larger cities in Canada," he said.

"As we continue to assess usability and feasibility, additional information may be shared in the future."

No more assessment needed

The head of the wastewater surveillance project at Dalhousie University said his team has talked with the provincial government a number of times.

"But that's been about the extent of our interaction, is just to share and inform and provide updates on best practices," said Prof. Graham Gagnon, director of the Dalhousie University Centre for Water Resource Studies.

He doesn't think any more feasibility assessment is required to proceed with wastewater monitoring in New Brunswick.

"I think it's sort of well-established protocols for measuring SARS-CoV-2 in wastewater at this point," he said.

Nic Meloney/CBC
Nic Meloney/CBC

His team has been testing samples for COVID-19 indicators at the Halifax region's four main wastewater treatment plants, Dalhousie student residences and at multiple other communities and locations since December 2020.

The U.S. Centers for Disease Control is monitoring SARS-CoV-2 in wastewater in more than 500 cities, he said.

COVID-19 is a respiratory illness with a wide range of symptoms. SARS-CoV-2, the virus that causes COVID-19, can also affect the gastrointestinal system and is shed in the feces of people infected with the virus in a form of genetic material called ribonucleic acid (RNA), which can be found in the wastewater.

This shedding typically begins five to seven days before people develop symptoms, which is why results can be used as an early warning trigger.

Gagnon's team detected Omicron in wastewater in November, for example, weeks before the variant was officially confirmed in Nova Scotia. He passed on the results to university officials, who used the information to warn students, who were all vaccinated and testing negative.

"Different agencies globally have used this information from a public health standpoint to understand population dynamics," he said. The Northwest Territories, for example, have used it to trigger school closures.

LuminUltra
LuminUltra

The results are reliable, said Gagnon.

"We use a PCR test, the same type of PCR test that you would use from a nasal swab."

The technology was developed in partnership with Fredericton-based LuminUltra, which has since patented and commercialized the process and sells it globally, he noted.

"So I don't think there's any real need for them to do any more feasibility as they're already supplying many cities, at a global level, their technology. And there's other companies in the United States, in Europe that sell competitive technologies."

Sewage systems wouldn't be a factor either, according to Gagnon.

"We've measured, as I said, right outside of a university residence and so … those samples never actually even touched a sewage system," he said. "And then when we measure in Halifax or in some of the communities in Nova Scotia, we would get right at the wastewater before it even enters into the wastewater facility."

Jordan Schmidt, a scientist and director of product applications with LuminUltra, said there's lots of flexibility in where and how to collect samples.

It could be from a manhole, at the outlet of a long-term care home, dormitory, or other population of concern, for example, or from a main wastewater treatment plant to measure an entire city.

Could help with personal risk assessment

Schmidt believes wastewater monitoring can play a larger role as more jurisdictions lift COVID-19 restrictions and testing rates continue to drop.

He said it would help people make decisions about whether to pursue some social activities or when and where to use a mask.

"I think it's good to have information to allow individuals to make that kind of personal risk assessment as to, you know, what they feel comfortable with," he said.

"This could be used as a very simple indicator of … how many infections are kind of currently out in your community and then lets you make that assessment as to what your comfort level is."

LuminUltra recently won a contract with the U.S. Centers for Disease Control and Prevention to do a three-month pilot project providing this type of surveillance data at 500 sites, said Schmidt.

"Certainly jurisdictions around the world of similar size and capacity [to New Brunswick] are doing this type of testing, but everyone's kind of dealing with, you know, different stressors."

6 deaths, 168 people in hospital

New Brunswick recorded six more COVID-related deaths last week and the number of people currently hospitalized because of the virus increased to 87 from 79, according to Tuesday's COVIDWatch update from the government, including 13 in intensive care, up from six.

The province's hospitals are actually treating a total of 168 patients either for or with COVID-19, 19 of whom require intensive care, according to figures released by the Horizon and Vitalité health networks. That's down from 192 and 21 respectively last week.

There are 3,964 new cases, based on lab-confirmed PCR tests and self-reported rapid tests, and 3,134 active PCR cases.

Government of New Brunswick
Government of New Brunswick

Moncton spokesperson Isabelle LeBlanc declined to release any of the city's wastewater sampling results or to give an interview.

"Unlike other provinces or cities, the intention of our participation is merely to offer Dal University with a research project and area to add to their work.

"It is not for using it for advising the public or for results. Public Health is aware of the data in case they might see value or possible use in it," she said in an email.

"We're not sure how the perception has become the same as what Ontario is doing. We have merely provided Dal with another city to test their research approach, theory, tools, etc. that's it."

Macfarlane, who repeatedly referred to the Moncton testing as a "pilot project," said Public Health is currently reviewing the results that have been shared with it, "among other partners."

"Readings have been shown to vary over time, with the current observed peak in March 2021."

He did not provide any figures.

'Almost unlimited opportunities'

Asked what types of issues need to be considered in determining the feasibility of a wastewater monitoring program, Macfarlane repeated, "As we continue to assess usability and feasibility, additional information may be shared in the future."

Asked what types of costs, human resources and equipment would be required, he provided the same answer.

Asked whether the government is considering monitoring provincewide or just in some large centres, he provided the same answer.

Asked how long before a decision might be made and how quickly a program could be up and running, he again provided the same answer.

Schmidt contends there's "almost unlimited opportunities" for how the technology might be applied in the future, but in particular for public and environmental health protection.

That could include identifying when there is bacteria of concern that require beach closures within a few hours instead of up to two days, monitoring for anti-microbial resistance genes from long-term care homes, and optimizing processes to ensure wastewater is treated appropriately and that potentially harmful organisms are not passed on to rivers, lakes and oceans.

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