New French survey confirms most Covid contaminations stem from eating in groups
Researchers from the Institut Pasteur in France have released a study which suggests that going to a restaurant or having guests over for a private dinner plays a key role in the transmission of the coronavirus, more so than taking public transport or shopping.
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For the study, called ComCor, researchers interviewed 3,400 people infected with Covid-19 and 1,700 others who did not have the virus. It sought to find out which factors - like professions, mode of transport, places visited -differentiated participants who had contracted the virus from people who had not.
It was carried out by the Institut Pasteur in October and November, during an initial period of curfew and then the second lockdown which saw most establishments partially or completely closed.
44 percent of those polled said they knew who had transmitted the virus to them, and in 35 percent of cases it was a member of their family.
Outside the home, infections were generally connected to a family environment (33 percent), a work environment (28 percent), or among friends (20 percent).
21 percent were able to pinpoint an exact event where they were infected, while 35 percent said they didn’t know.
In 93 percent of cases of infection in the home, people said they did not wear masks, even when there were obvious symptoms. Most people said they were conscious their behavior was "risky".
Indoor riskier than outdoor
In all cases, most infections happened in a closed, indoor space, such as the home (89 percent) or workplace (96 percent).
Researchers found that frequenting restaurants, bars or gyms was associated with an increased risk of infection, whereas using public transport and visiting shops were not.
On the list of risky professions were blue collar workers and drivers. Teachers and farmers, meanwhile, appeared on the list of those less likely to be infected.
"This suggests that [teachers and farmers] are better able to protect themselves within their professional environment," the study said.
"We saw an increased risk associated with frequenting bars and restaurants," said the lead author, Arnaud Fontanet, an epidemiologist and member of the scientific council guiding the government.
Fontanet pointed out that because bars and restaurants were not functioning as normal during the poll, it was difficult to gauge their exact role in transmission.
"That suggests that some bars and restaurants were open in a clandestine manner, and clients who went there were exposed to greater risk of infection," he suggests.
French cafes and restaurants have remained closed even after nationwide restrictions were eased earlier this week.
Meals in groups a source of infection
However, by using health insurance data to pinpoint different circumstances of infection, with surveys of 25,600 infected individuals, ComCor found that regardless of the public or private sphere, "meals play a central role in these contaminations", as people sat close to each other without masks.
"Private meetings - families, friends - are the main source of infection," Fontanet said.
"If people have friendly dinners at their homes rather than going to a restaurant, it doesn't make a difference."
The researchers stressed the importance of organising end of year gatherings in "the safest way possible" to protect vulnerable people over the holidays, by respecting required health measures such as social distancing, mask-wearing and hand-washing.
In terms of self-isolation, while over 97 percent of infected people said they respected lockdown, only 54 percent did it when symptoms first appeared, and 64 percent did so as soon as they found out they were a contact case.
The government is hoping to remedy this delayed reaction with its new "test-alert-protect" strategy and better follow-up and assistance for patients testing positive.
Although the results from the Institut Pasteur speak for a small portion of the population in restricted circumstances, they "correspond to data collected from other studies on Sars-CoV2", notably in the United States during the first wave, which revealed restaurants as the number one contamination zone.
"Sharing our knowledge will help us come up with better recommendations in terms of prevention and transmission, and help us to better adapt measures to each situation," said Daniel Lévy-Bruhl, director of respiratory diseases and vaccination at Santé Publique France, a partner in the Pasteur study.
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