The list of species infected with H5N1 avian influenza continues to grow. Many wild or farmed mammals have recently been infected with the disease, which worries the World Health Organization. But if before the mode of contamination for mammals seemed to be the ingestion of contaminated carcasses, a new phenomenon of transmission of the disease between mammals seriously worries the health authorities.
Avian flu back: “The circulation has increased sharply, it is a very violent disease”
A mink farm located in the Spanish province of Galicia has been severely affected by the epidemic. This is cause for concern for the international scientific community, because the mink is very close to humans and the virus is spreading significantly. Indeed, the pulmonary physiology of this mammal makes it an excellent laboratory animal model and allows studies to be carried out on the virulence and transmission of influenza viruses in humans. Mink might be considered a springboard species for the spread of influenza from poultry to humans.
However, the World Health Organization wants to be reassuring, even if it does not rule out the possibility that the virus evolves and is capable of transmission between humans. Tedros Adhanom Ghebreyesus, the head of the WHO, calls for vigilance: “Recent transmissions to mammals should be closely monitored”. “For the moment, the WHO assesses the risk for humans as low. Since the appearance of the virus in 1996, transmission of H5N1 to and between humans has been rare and unsustainable. But we cannot assume this will remain the case, and we must be prepared for any change in the status quo” he adds.
Another worrying element is that the more the virus spreads among mammals, the greater the risk of mutations, especially those that would make transmission between humans possible. Especially since for the first time in Europe, the virus would have spread by airborne transmission. “This is suggested by the increasing number of infected animals identified following confirmation of the disease and the progression of infection from the initially affected area to the whole farm.” as explained in the journal of epidemiology Eurosurveillance.
