the growing number of mammals infected with the virus worries the WHO

A teenager is being treated at a Canadian children's hospital for avian flu caused by the H5 strain virus. Since the start of 2024, strains that have appeared in the United States have developed an unprecedented capacity to contaminate new species.

A teenager was infected with bird flu in Canada, reportSaturday November 9, the authorities. Although this is not a first, the virus is affecting mammals more and more frequently, which worries the World Health Organization (WHO).

This new contamination reminds us of the worrying mutations of avian flu across the Atlantic. Since the start of 2024, strains that have appeared in the United States have developed an unprecedented capacity to contaminate new species. The most spectacular are the dozens of cattle farms hit by the virus in several American states.

Then there were transmissions to humans, all of whom came into contact with the animals, all except one. In Missouri, an enigmatic case remains. A man was hospitalized in September with no connection to the agricultural world. Was he contaminated by another human? No response at this stage. Human-to-human transmission has never been observed, which remains reassuring.

These American strains do not currently threaten Europe or France. When contacted, Jean-Luc Guérin, from the Toulouse veterinary school and expert in avian flu, was reassuring. In Europe, the virus remains in its classic form. It almost exclusively contaminates wild birds and poultry on farms. France also raised the risk to the maximum level this weekend due to the increase in contamination, with the compulsory confinement of animals, as has already been the case on numerous occasions.

However, we must remain cautious to avoid finding ourselves in a situation similar to that of the United States. It is necessary, firstly, to control animals arriving from across the Atlantic to avoid importing American strains. In addition, since 2023, the vaccination of duck farms has made it possible to limit the spread of avian flu and therefore mutations. A mechanical phenomenon: the less a virus circulates, the less likely it is to develop new capacities.

Most of the fight against these variants eludes us, however. It is played in the United States. It is up to them to isolate cattle farms affected by these new strains, through quarantines, slaughtering livestock and detecting possible other mutations, so as not to be caught off guard again.