When the virus has begun to circulate in Quebec?

Photo: Agence France-Presse
First discovered in the city of Wuhan, in China, the new coronavirus may have appeared in Québec at the end of 2019.

Thousands of samples collected in Quebec weeks before the outbreak of COVID-19 begins to get tough will be tested to see if the virus SARS-CoV-2 had been circulating in the population in late 2019 and early 2020.

This research project will be launched this summer by the public health Laboratory of Quebec (LSPQ), thanks to specimens collected last fall and early winter in the framework of the regular programme of monitoring of the influenza. This program, piloted the past 15 years by the Institut national de santé publique du Québec (INSPQ), will allow researchers to gain access to the frozen samples from thousands of patients who have consulted to experience flu-like symptoms in dozens of family medicine groups (GMF) and clinical across Quebec from October 2019.

“Thanks to these samples collected before the pandemic, we will be able to find the virus and whether individuals were infected as early as December or early January before the first cases are reported “, explained Tuesday to the Duty Dr. Hugues Charest, head of the sector of molecular biology to the LSPQ.

Approximately 1,500 samples will be as well screened to attempt to elucidate a question which turlupine several scientists from research conducted in other countries have demonstrated the presence of cases of COVID prior to the official date of the beginning of the pandemic.

In France, the research was able to detect a case of COVID, as from 27 December — and we even suspect one another of having been diagnosed on 16th November — a full month before the first three cases the official confirmed by test in france on the 24th of January. In the United States, researchers estimate that the virus was circulating as early as November or December in New York, although a first case has been confirmed that the January 21, in the State of Washington. In China, experts in genomic analysis of strains of the virus have estimated that the SARS-CoV-2 may have appeared in humans as early as the end of the month of August.

In Quebec, a first case was officially confirmed on 28 February, a Montreal-based return to Iran, arrived aboard a flight from Qatar.

But according to Dr. Charest, it may be that infections with the virus SARS-CoV-2 to be passed under the radar in December and January in the hospitals and clinics where patients have consulted for influenza-like symptoms of. While Quebec was not yet in a ” warning “, that travellers infected would have been able to return to a destination where the COVID had been circulating.

Data | Our interactive content on the COVID-19

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According to Dr. Gaston de Serres, an epidemiologist with the INSPQ, the samples collected to monitor influenza are very valuable. “It is sure that there is a risk to find cases, even if it is likely to be very little “, he believes.

The fact that only a portion of the 1500 samples collected across the province from the metropolis, where the epidemic hit first and the hardest, does, however, reduce the possibility of finding more cases early. These samples also exclude from the outset the patients with other typical symptoms of the COVID, including anosmia, headache, or diarrhea, that would have been able to see clinically, ” says Dr. Greenhouse.

“Over the past 15 years, this network of surveillance is valuable for tracking the flu, and verify the effectiveness of the flu vaccine. It is also to monitor the emergence of other viruses. A few years ago, it has been know that an enterovirus causing paralysis in children was also present in the adult, without that they don’t have symptoms, ” explains Dr. Greenhouse.

A thousand other samples collected in the four hospitals of the province to Trois-Rivières, Quebec, Rimouski and Chicoutimi, among patients hospitalized for complications of influenza will also be integrated into this project of screening ” prépandémie “. The ministry has also asked that the detection of SARS-CoV-2 to be integrated from next year to this program, one-time monitoring of respiratory viruses in hospital setting, ” explains Dr. Rodica Gilca, a medical consultant at the INSPQ.

British Columbia, which has a sentinel network of physicians, has already begun this process and will be completed in a few weeks the screening of samples dating back to November 2019, said yesterday the Dr. Danuta Skowronski, head of the surveillance for influenza and respiratory pathogens emerging from the BC Center for Disease Control. “But we do not expect to find many cases, because the prevalence was very low here.”

According to Dr. Charest, the LSPQ, the calm to begin to know the laboratories contribute to detect the COVID will allow this research project to start as early as the end of the summer.

“The teams, mobilized since the beginning of the pandemic, are tired. It (the project) was not a priority. But then, the number of tests to analyze decreasing every day. This research will help us to better understand what happened in Quebec, maybe even to discover some characteristics of the virus that we are still, ” he says.

This research complements that already undertaken by other quebec researchers associated with Genome Canada, to complete the genomic sequencing of samples from 50,000 patients reported positive to the COVID since 28 February. A work which should allow to learn more about the circulating strains in Quebec, on their contagiousness and give them the tools to choose which vaccine is most appropriate for protecting the population.

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