A mutation of the avian flu virus, discovered through the case study of two infected people in North America, is causing concern. In an editorial in New England Journal of Medicine published on December 31, two experts speak of “the growing threat of H5N1 to human health”. But there is no reason to panic, say Quebec experts.
“It is certain that it is worrying,” immediately affirms Jean-Pierre Vaillancourt, professor at the Faculty of Veterinary Medicine at the University of Montreal, who works in different research groups on the epidemiology of zoonoses and the public health.
But, for the public, there is no “direct concern for the moment”, he assures. “For human beings, the focus must be on farm employees, breeders in poultry and monitoring for [ceux qui travaillent avec] dairy cattle. » Indeed, the vast majority of cases reported in the United States concern people who work with animals.
“It takes close contact with sick animals or close contact with a contaminated surface,” explains Mr. Vaillancourt. This is why I say that for ordinary people, for the public, there is no reason to panic. The risk of someone like you becoming infected is very low, unless the virus becomes able to pass from one human being to another. But there is a good chance that we will know before it affects everyone because we do a lot of surveillance, we test in several places. »
According to him, Canada does better than the United States in terms of surveillance. He sees “an effort on the part of Public Health to dialogue with veterinarians” and with wildlife specialists who work with wild birds. “It’s coming together, and I would say that Canada is better placed than the United States currently. There is a flow of data and information exchange that is better than in the United States. »
The other good news, he says, is that in Canada, unlike the United States, there is no reason to believe that dairy cattle are infected. “We would know if there were any,” he assures. But we currently have outbreaks in domestic birds. British Columbia is the most affected province. Afterwards, it’s Alberta. In Ontario and Quebec, recently, we have had a few outbreaks, so the virus is in the environment, we have to be careful. »
Canadian teenager
It was in British Columbia that the first human case of H5N1 flu in Canada was detected in the fall. According to the case study, which was published in the New England Journal of Medicinethe 13-year-old had to be hospitalized and intubated. She is now out of danger. In the United States, of the 65 people who were infected, only one man was hospitalized. But what is worrying is that in both cases the source of infection has not been determined.
The other element is that in the case of the Canadian teenager, the researchers discovered “three mutations [du virus] potentially associated with increased virulence and human adaptation,” write editorialists and specialists Michael G. Ison and Jeanne Marrazzo in the New England Journal of Medicine. “We do not know whether these mutations were present in the infectious virus or whether they appeared during the patient’s illness,” they specify.
According to an Agence France-Presse article published at the end of December, a mutation of the virus was also observed in the American sixty-year-old who was hospitalized after being contaminated by the H5N1 virus.
No human transmission
The avian flu virus has been around for a long time, but it was not until 1997 that it became highly pathogenic. Since then, animals have been infected on all continents. “It is in more than 120 countries in the world, in at least 489 species of domestic birds and wild birds, dozens of mammals,” specifies veterinarian Jean-Pierre Vaillancourt.
In humans, there have been deaths, notably in southwest Asia and Egypt, but the virus has never been transmitted from person to person. “The concern of Public Health is that someone like you and me will have influenza in their human system, which will be able to reassociate neither more nor less with avian influenza,” explains Mr. Vaillancourt. In other words, if you have two strains of influenza in your body, you become a vessel [qui va] allow an exchange of genetic material between two viruses. » These mutations could then make transmission between humans possible. “If that happens, we would have a situation potentially comparable to COVID-19,” predicts the specialist.
But we are far from being there, he assures us. And, unlike COVID-19, which took the world by surprise, experts have been preparing for an avian influenza pandemic for a very long time.
An “expected threat”
An observation shared by Denis Archambault, from the Department of Biological Sciences at UQAM. With his team, the researcher recently made a major breakthrough by developing a vaccine that could attack any variant of the H5N1 influenza virus. A pandemic of avian flu among humans following the evolution of the virus is a possibility for which the environment is preparing.
“It’s an expected threat,” he says. When it will happen, we don’t know. And maybe that won’t happen. This is another option. »
For experts, we must therefore remain on the lookout, continue to monitor on all levels and continue research to develop vaccines.
“Without a better understanding of the extent of virus exposure, infection, progression and transmission, we will be unable to adequately protect our communities from a pathogen that has proven to be a formidable challenge for human and animal health,” conclude the editorialists of the New England Journal of Medicine.
