Coronavirus hits deer populations

Nearly half of the white-tailed deer tested in four US states carry SARS-CoV-2, the coronavirus responsible for COVID-19, according to a new study. Everything indicates that deer in Quebec are also infected, according to experts, who recommend that hunters put on masks and gloves before handling their prey. Other animal species are also likely to be infected: the Granby Zoo is preparing to vaccinate around a hundred animals.

Mathieu Perreault
Press

“Disturbing”

“I would have expected a much lower infection rate,” explains Steeve Côté, white-tailed deer expert at Laval University. “Deer don’t live that much in groups, they don’t have much contact with humans. I imagine there is a source of contagion somewhere, maybe sewage. “Mr. Côté considers that such a high presence of antibodies to SARS-CoV-2 is” worrying “, but emphasizes that there is” no evidence of infections from animals to humans for the moment “. Hélène Carabin, veterinarian at the University of Montreal, believes that the study, conducted on deer populations in Illinois, Pennsylvania, Michigan and New York State, shows the need for “multi- species’ of viruses. “It’s really important to treat infectious diseases holistically, without distinguishing between animal health and human health, because they can switch from one to the other. This concept of “one health” (One Health) is more advanced in the United States, according to Omar Ndao, director of the National Reference Center in Parasitology at the McGill University Health Center (MUHC). “The study was done because they take blood samples from deer that they keep for ten years, so you can do tests on the years before disease onset. According to Mr. Côté, screening for SARS-CoV-2 in white-tailed deer has not been done in Canada.

Precautions

According to the D^D Carabin, hunters should wear gloves and a mask when handling deer they have just slaughtered, “especially if they are not vaccinated.” “That said, at this time, there is no evidence of animal-to-human transmission. “And in the park of Longueuil struggling with an overpopulation of deer,” you really have to get very close for there to be a risk, but I would say that perhaps unvaccinated people could wear a mask if they often meet deer ”.

Reservoir and mutations

The presence of SARS-CoV-2 in deer is not a problem only because it can infect hunters. They can also constitute a “reservoir” of the coronavirus, which could remain in circulation even if it is eradicated in humans, and mutations could arise and be transmitted to humans. The D^D Carabin and M. Côté emphasize that humans are for the moment a more important source of exchange of the virus and therefore more conducive to mutations, and that the eradication of SARS-CoV-2 in Canada is not for tomorrow. “With Lyme disease, for example, the deer is a secondary host, but the main reservoir is the mouse,” says D^D Carabin. In September 2020, a Danish study published in the journal Nature concluded that the SARS-CoV-2 mutations observed in mink were not problematic for humans. At the start of the pandemic, millions of mink were wiped out when outbreaks appeared on farms in Europe.

The vaccine at the zoo

Earlier this year, several gorillas at the San Diego Zoo became ill with COVID-19, presumably infected by visitors. The episode sparked a race for the veterinary vaccine, which will benefit residents of the Granby Zoo within a few weeks. “There has already been a first wave of vaccination in American zoos, and we are part of the second,” explains Émilie Couture, veterinarian at the Granby Zoo. The species most vulnerable to the disease are felines and primates, as well as some cousins ​​of ferrets, according to the D^D Sewing. Birds and cattle are relatively protected. The veterinary vaccine, developed by the US veterinary firm Zoetis, consists of two doses given three weeks apart, with the same dosage for all animals, large and small.