When the numbers came in — 28 positive COVID tests in a single Sherbrooke neighbourhood over a nine-day period this month — the regional health authority raced to where the virus was.
A mobile testing centre — a key cog in the machinery to thwart the spread of the virus — was dispatched.
As the screeners arrived early Thursday afternoon to set up their equipment in the parking lot at Église du Précieux-Sang in Ascot, a neighbourhood on the city's south side, about 50 people were already in line.
Additional staff were quickly summoned, and by 4 p.m. a total of 180 residents from the area had been tested.
Several dozen more were turned away.
"This is what we wanted," Dr. Geneviève Petit, a public health specialist with the CIUSS de l'Estrie and CHUS, told Radio-Canada. "We wanted to raise awareness. We went to a lot of effort with our community partners to get people tested."
Many of those who joined the queue decided to get tested for preventive reasons.
"I don't have any symptoms," Laurie, a CEGEP student, told Radio-Canada. "But I live in the area and I'd rather be cautious. I don't want to contribute to propagating (the virus)."
On Friday, business was even better: 245 people stepped forward to be tested.
All the results should be known by Monday. Those who test positive will be informed by public health this weekend so their contacts can be traced.
Either way, the CIUSS now has specific, up-to-date information about 425 more people in its records. That, health officials say, is a win.
New cases revealed
As the mobile testing in Ascot ramped up, public health revealed an additional five cases in the area.
But health officials don't view the news as all bad: it's evidence the system is working.
For one thing, CIUSS officials said the testing confirmed the cluster stems from multiple sources, and thus does not qualify as a single outbreak.
The overall number of COVID-19 infections in Quebec has ticked upward over the past week (including 98 new cases on Friday) and as provincial health officials brace for a second wave, the rash of infections in Sherbrooke stands as an illustration of how the battle to keep the spread in check in the regions is unfolding.
On Friday, public health officials in Drummondville invited recent users of a skateboard park to get screened for coronavirus and sent a mobile testing unit to the area. A nearby CLSC will offer drop-in testing through the weekend.
The CIUSS de l'Estrie will also be busy this weekend as it deals with a resurgence of the virus in a long-term care facility in Lambton, Que., 95 kilometres northeast of Sherbrooke. The plan is to test 29 residents and some 50 staff in the coming days.
Targeted testing of specific populations allows for more prompt and effective contact tracing, which further speeds the public health response.
"If you can do something to make those tests get done in the right population, faster, and get the answers out faster, like bringing the clinic to the patients ... then I think that's of great benefit to public health, which is going to benefit the entire population," said Dr. Matthew Oughton, an infectious disease specialist and professor of medicine at McGill University.
The mobile test centre isn't the first time such measures have been deployed in the province, although it was reportedly a first for the CIUSS de l'Estrie.
The game plan may soon change
"I think the strategy for testing will probably vary over the coming months depending on what is the epidemiological situation," said Dr. Gaston De Serres, an epidemiologist at the Institut national de santé publique du Québec. "As long as the number of cases remains low, I guess we will stay with the current strategy."
Mobile clinics, he continued, are a helpful tool to investigate spikes and often indicate when a given community is letting its guard down in terms of sanitary measures like social distancing.
In De Serres's view, people have mostly followed public health guidelines, but in a few weeks' time that may not be enough.
"During the winter season, in general, the environmental conditions are more favourable for the transmission of respiratory viruses," De Serres said. "So what works during summer time may not be sufficient during winter."