MONTREAL -- Hearings into the deaths of Quebec's elderly during the first wave of the COVID-19 pandemic continue Thursday with National Health Director Horacio Arruda expected to give testimony.

Meanwhile, the Institut national de la santé publique (INSPQ) has pointed out that N95 masks have not proven to be more effective against the virus than medical masks.

"In the field studies, whether people used a medical mask or an N95, it made no difference," said Dr. Chantal Sauvageau with the INSPQ during her appearance Wednesday at the hearing, presided over by Coroner Gehane Kamel.

In recent weeks, the organization has been criticized by several witnesses for not applying precautionary principles regarding possible airborne transmission of the virus.

This type of propagation requires, among other things, the use of an N95 mask, which the INSPQ never recommended during the first wave, except in certain specific cases where medical equipment affected the ambient air.

The INSPQ says it now acknowledges that part of the transmission "is by airborne aerosols," but that "there is no direct evidence that this virus is airborne, i.e. that it prevails over longer distances."

The studies referred to by Sauvageau were mostly done in hospitals, where contact with patients is not the same as in CHSLDs where residents are often losing autonomy and need an employee to be in physical contact with them over an extended period of time to perform certain tasks.

DROPLETS AND AEROSOLS

"The vast majority of transmission is by prolonged contact, that's the consensus," explains Sauvageau.

Once a person is infected, household members have a one in five chance of catching the disease, she said. If the virus was airborne, "they would all get sick."

She acknowledged that "a few outbreaks where there appeared to be cases that could not be explained by close contact" have been recorded around the world, but they remain a small minority "in the mass of data."

"In each of these cases, there was an additional factor," she said, citing an example at a restaurant, where ventilation was strong, but only in one direction.

While several tables were contaminated because of a single infected person, "at the tables that were upstream of that source, no one was infected."

A LABYRINTH OF INFORMATION

The INSPQ says it made its recommendations "as best it could" despite "contradictory scientific literature," argued the organization's associate vice-president for scientific affairs, Dr. Jocelyne Sauvé.

"What is true today can be disproved tomorrow," she explained, noting that many articles were published during the pandemic without peer review for the sake of speed.

The INSPQ insists it had to rely on ever-changing information, keeping in mind that "the best recommendation possible under the circumstances was better than no recommendation at all."

When asked about the fact that an article defending the airborne theory had been published in a scientific journal even before the first wave, Sauvé replied: "you don't base a decision on one article," but on a scientific consensus.

"How many times has it happened in the scientific literature that an article is published and a few months, a few years later we learn that, oops, it's not good after all?" she stated.

THE INQUIRY

The coroner's inquest is looking into the deaths of elderly or vulnerable people in long-term residences during the first wave of the COVID-19 pandemic.

From Feb. 25 to July 11, 2020, Quebecers aged 70 and older accounted for 92 per cent of deaths due to COVID-19, according to data from the INSPQ.

The goal is not to point fingers, but to make recommendations that prevent future tragedies.

Six CHSLDs and one seniors' residence were chosen as a sample and one death from each establishment was examined.

-- This report by The Canadian Press was first published in French on Nov. 11, 2021.

-- This article was produced with financial support from Facebook and The Canadian Press News Fellowships.