The concentration of COVID-19 in the wastewater of several cities in Quebec is on the rise. This increase occurs at a time when the new BQ.1 variant is becoming more and more established in Quebec.
Updated yesterday at 10:43 p.m.
Faced with the difficulty of maintaining a high level of tests, Quebec has put forward several methods to try to follow the evolution of COVID-19. One of them consists of analyzing the presence of particles in the wastewater of about ten cities in the province.
And precisely, for a week, the concentration of particles of COVID-19 has doubled in the sewers of Montreal, Laval, Quebec, Gatineau, Rimouski and Sept-Îles.
“That means there are probably more people shedding the virus, whether they are symptomatic or asymptomatic. It gives us an indication of the virus content in the water, therefore the extent of people infected, ”says the medical adviser to the National Institute of Public Health of Quebec (INSPQ), Caroline Huot.
A good picture of the situation
The increase noted in these cities gives a good portrait of the situation, she specifies, since they represent more than 50% of the population monitored with wastewater. “When we see that it is increasing in these cities, it gives us an interesting indication for a good part of the population of Quebec”, says the medical advisor.
Conversely, Trois-Rivières, Sherbrooke, Saguenay and Saint-Georges-de-Beauce have not seen an increase, the concentration of COVID-19 having even decreased in recent weeks. It must be said that these four cities experienced a strong wave of cases at the beginning of October and that this is now tending to subside.
The DD Huot also urges caution when it comes to comparing cities based on the rate of COVID-19 particles found in their wastewater.
This sharp increase detected in wastewater did not materialize in the number of cases detected by PCR tests. On the contrary, the number of cases had been falling for a few weeks, but has stabilized recently.
However, these tests are now reserved for certain categories of the population, including health care workers and residents of certain environments, including RPAs.
With the availability of rapid tests, these people may be less tempted to go out to go to a clinic to perform a PCR test, says professor at the School of Public Health at the University of Montreal, Roxane Borges Da Silva. “Sewage can be trusted more than any other method at this time” to measure the spread of COVID-19, she adds.
On the other hand, self-reported cases, i.e. those reported by citizens to the Ministry of Health and Social Services, have shown a slight increase over the past week.
Another method used to try to follow the COVID-19, the INSPQ also conducts surveys of Quebecers to assess the progression of the pandemic. According to estimates established through these probes, between 23,000 and 31,000 people are infected every day.
This is significantly more than the 807 cases detected on average daily by PCR tests.
BQ.1 takes up more and more space
This increase comes as a new variant seems to want to settle in Quebec.
The BA.5 sub-variant and its sub-lines remain in the majority at present, but its cousin BQ.1 is taking up more and more space. Detected for the first time at the beginning of September, it represented 19% of new cases detected at the end of October.
The impact of this increase and the arrival of BQ.1 will be monitored, says Professor Roxane Borgès Da Silva. “You have to check its vaccine escape capacity, that is to say to what extent does it infect vaccinated people and send them to the hospital? Are the symptoms that are developed the same as before for other variants? “, she lists, among others.
For the time being, hospitalizations seem to remain stable. Of the 1,841 people hospitalized with COVID-19, 632 were admitted due to complications from their infection.
As for the deaths attributed to COVID-19, Quebec deplores about ten per day on average. These are mainly people aged 80 and over who were living at home when they were infected. There are no major outbreaks in CHSLDs or RPAs.
Vaccination in slow motion
Moreover, the vaccination campaign continues to slow down in Quebec. The province is administering an average of 17,200 doses per day, down 13% from last week. Despite this slowdown, vaccination coverage is up slightly. Taking into account the fact that Public Health recommends getting vaccinated after five months, 23.9% of Quebecers currently have their vaccinations up to date.
Assessment of COVID-19 in Quebec
PHOTO ROBERT SKINNER, LA PRESSE ARCHIVES
The spread of COVID-19 remains stable in Quebec as the province reports a slight increase in hospitalizations and 11 new deaths.
The 11 new deaths reported on Wednesday bring the daily average calculated over seven days to 10. The trend is up 6% over one week.
Quebec is also reporting an increase of six hospitalizations on Wednesday. The 1,841 people currently hospitalized represent a drop of 5% over one week. In intensive care, the 41 patients represent a decrease of 9% over one week.
On Wednesday, there were also 3,647 health network workers absent due to the pandemic, a stable trend over a week.
The 899 new cases reported on Wednesday bring the daily average to 807. The trend is thus stable over one week. These numbers likely reflect only a portion of total infections, due to limited access to PCR testing. Moreover, the proportion of PCR screening tests proving positive for COVID-19 remains high, at 8.6%.
In addition to the cases detected by PCR tests, 288 people have also reported in the past few days having tested positive on a rapid test. Self-reported cases, which are not included in daily reported cases, have increased by 13% over the past week.
