Wastewater shows COVID-19 spike
Monitoring reveals virus doubled in past month, up 10-fold since June
Samples taken from Ottawa's sewage treatment plant show the concentration of COVID-19 in the city's wastewater has doubled in the past month and is 10 times higher than it was in June.
The findings mirror the spike in cases seen in the city since the second wave of the pandemic began. Ottawa is considered a provincial hot spot. The wastewater tracking system, developed by local researchers, is now being used daily by Ottawa Public Health to monitor the spread of COVID-19.
Wastewater tracking has been studied by researchers in Ottawa and elsewhere since the beginning of the pandemic. But at a time when cases are increasing and the system of testing, tracking and tracing is strained, it could have a new appeal across the province.
Wastewater sampling offers a measure of COVID-19 that is not influenced by how many people are being tested. Crucially, sampling wastewater measures virus that has been shed by people before they show symptoms and are less likely to seek, or qualify, for testing.
“We all contribute involuntarily,” said Dr. Alex MacKenzie, senior scientist at the CHEO Research Institute. “It doesn't matter how many people are asymptomatic or how many people get tested. It is just there.” And researchers say monitoring COVID-19 concentration in sewage can do more to help health officials better understand and prevent its spread.
Researcher and uOttawa engineering professor Robert Delatolla, who developed the program along with MacKenzie and others at CHEO, said he is optimistic the monitoring system could soon be used provincewide to help catch outbreaks before they begin in vulnerable communities.
Those behind it want to see it and other similar projects expand across Ontario with government funding.
Delatolla said targeted waste water monitoring can act as a kind of “smoke detector” for outbreaks in long-term care homes and other vulnerable institutions. It could allow targeted action to be taken before widespread transmission of COVID-19 takes place, or to raise an initial warning about an outbreak that hasn't yet been identified. It could be done at less cost, using fewer resources, than other methods.
“We see waste water tracking as a potential tool to help alleviate the strain on public health,” he said.
The work on waste water tracking began, said MacKenzie, because most other research went dormant last spring at the beginning of the pandemic.
“It is an example of a bunch of concerned Canadians who got their livelihoods taken away in terms of regular research who looked around and said, `What else can we do?'” he said.
MacKenzie, who usually researches rare childhood diseases, has developed a means of tracking COVID-19 in waste water by measuring proteins, rather than RNA, which is the current system. The technique, he said, was borrowed from his brother Malcolm who developed it at a biotech company in Boston. MacKenzie is part of a team that has submitted a research paper on protein testing for COVID-19 waste water tracking.
He believes it is the first time the technique has been used for tracking COVID-19 in waste water and eventually could become a more sensitive tool for determining how much COVID-19 is in a community by testing waste water.
Delatolla said the Ottawa team has collaborated with others across the province.
Delatolla said the case has been made to the province that waste water testing helps in catching outbreaks before they spread to reduce COVID-19 cases in longterm care and other institutions.
In the U.S., sewage tracking has helped uncover COVID-19 in some university dorms, preventing widespread outbreaks. Officials at the University of Arizona, for example, tested more than 300 people after waste water sampling found COVID-19. The tests identified two asymptomatic people.
Across Canada, though, it had mainly been used on an experimental basis until Ottawa Public Health recently began using the data daily.
The work being done at CHEO and uOttawa labs, in collaboration with other researchers around the province, has benefitted individual scientists, in addition to the broader community.
MacKenzie says the work he has done is “one of the more engaging chapters” in his research career.
“It could be as transformative as any work I have done in the last 40 years.”
We see waste water tracking as a potential tool to help alleviate the strain on public health.