British Columbia is testing sewage samples for the genetic signature of COVID-19, and hopes to develop a program to monitor wastewater for new outbreaks of the virus – particularly in smaller communities – by this fall.
Bonnie Henry, Provincial Health Officer, said the B.C. Centre for Disease Control and Metro Vancouver have been running a pilot project, following on similar work in the Netherlands, Finland and Germany.
“And for the last five weeks, there has been testing done and we have had no positive [results], which reflects the low level of transmission that we are seeing in communities right now,” she told reporters Tuesday. “This is something that we’re planning on rolling out and using in the coming months.”
Dr. Henry said agencies across Canada have been working on the trials, and said the BCCDC is home to some of the leading experts in the field of assessing water samples for communicable diseases.
“I’m hoping by the fall in particular, that we’ll have that as another tool in our surveillance tool kit to help us, particularly in more remote communities where the presence or absence [in testing] can be very helpful,” she said. “In larger communities, as you can imagine, you have to filter and get a small amount to test and it can be a challenge, but there is some evidence that we can use it to give a barometer of how much transmission there is in a community.”
British Columbia, the first province in the country to see COVID-19 cases, now has one of the lowest rates of COVID-19-related death in Canada. The flattening of the curve allowed the province to begin a gradual restart one month ago. With schools, hair salons and restaurants reopening their doors, the number of new cases has increased only slightly, and Dr. Henry said the province remains on track to expand that restart now.
The next phase of the reopening, which could be announced as early as Wednesday, would permit non-essential travel within the province, including the reopening of hotels, resorts and provincial campgrounds.
But the public-health models show the province could easily see a rapid increase in COVID-19 cases if some restrictions – especially physical distancing measures – are abandoned.
“We run the potential risk of a rapid rebound of cases,” she cautioned. “We need to stay where we are, where we have safe contact.”
Currently, public-health officials estimate that British Columbians have reduced their contact with others to roughly 65 per cent of normal levels, and mobility outside of the home is largely still below prepandemic levels. The one exception is travel to public parks.
Increased travel opportunities this summer will mean more contact between residents and that likely will increase the transmission of the virus, she said, but that can be manageable. “Each of us has to keep those bubbles [of social contact] small,” she said.
The province has dramatically increased its capacity to conduct contact tracing – the investigative work of tracking down people who may have been in contact with someone who has tested positive for COVID-19 – and she said it is critical that those teams of communicable disease control experts are maintained through the fall, when a second wave of the disease is expected to land.
B.C. Health Minister Adrian Dix said British Columbians have succeeded in following the pandemic protocols to date, and urged residents to remain vigilant. “Physical distancing, I’m sure that of all the phrases we’ve used over the many months, those two words make the greatest difference in our effort to slow the spread.”
He pointed to new models, released Tuesday, that show increased social contact by even 5 per cent, to 70 per cent of normal levels, could push B.C. into a rebound of cases. “Today’s modelling ... shows what happens if we let up on physical distancing. It shows us once again that physical distancing saves lives.”
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