It is a disease that has been making a regular comeback in France since 2015. In a few years, avian influenza will have caused four epidemics. The last one declared itself at the end of last November with the appearance of a first outbreak in the North. Today, the country has 41 households mostly in the southwest. While humans cannot contract bird flu by eating eggs, duck breast or foie gras, they can contract the disease through contact with infected poultry. A pandemic in humans should not be ruled out either. We will explain everything to you.
What is bird flu?
Bird flu (also called avian influenza) is “a viral disease that is prevalent in birds and has a very high mortality rate in farmed birds” explains the Pasteur Institute. Since 2015, France has been struck four times by the disease. Last winter, 3.5 million poultry had to be slaughtered as a precautionary measure. In September 2021, avian flu officially disappeared before resurfacing last November with the appearance of an outbreak in a farm in the North. Today, France has 41 households.
Is transmission from poultry to humans possible?
Yes, but it is very unlikely in France. Jean-Luc Guérin, professor of avian pathology at the National Veterinary School of Toulouse, wants to be reassuring: “Today, the zoonotic power [qui se transmet de l’animal à l’Homme, ndlr] of the virus is extremely low. The only cases reported in Russia last year have not been confirmed”. The strain of the bird flu virus currently circulating in (H5N1) is the one circulating throughout Europe. No cases of transmission to humans have been identified. “HAS To date, no case of human influenza due to an avian influenza virus (known as a case of “avian flu”) has been declared in France” recalls on its Public Health France site.
On the other hand, this transmission is not impossible explains for its part Public Health France: “More than ten avian or porcine type A influenza viruses are currently capable of infecting humans. Human cases are mainly primary cases, following exposure to infected birds or to an environment contaminated, particularly in the context of live poultry markets”.
Several hundred cases of bird flu transmission to humans have nevertheless been declared, the vast majority of them in Asia since the beginning of the 2000s, also causing hundreds of deaths. For example, since 2013, the H7N9 strain has infected nearly 1600 people and caused 616 deaths according to the WHO (World Health Organization). The H5N1 strain has also killed several hundred people since 2003.
How is the disease transmitted?
The avian influenza virus is found mostly in droppings from infected poultry thus “only in their respiratory secretions” explains Public Health France. The virus is therefore found in the environment: contaminated dust or bodies of water. “Transmission to humans is by inhalation of contaminated dust or aerosols, or by contact when handling infected birds”. Infection can also occur at poultry markets.
What if we eat meat or eggs?
During his various speeches, the Minister of Agriculture Julien Denormandie repeats that the consumption of meat, foie gras and eggs – and more generally of any food product made from poultry – does not present any risk for humans: “All infected animals are removed from the food chain so there can be no infected meat. In addition, you can only get sick by the respiratory route and not by the food route” says Jean-Luc Guérin.
“We must not let this virus evolve”
“Today, there is no pandemic phenomenon” assures Professor Jean-Luc Guérin. Clearly, if a human contracts the bird flu virus, he does not transmit it. But we must be wary adds Jean-Luc Guérin: “We must not let this virus evolve like this in nature, the risk of a virus adapted to humans may emerge. There are mutations, genetic mixing”.
The very rare cases of human-to-human transmission of the H5N1 virus have remained episodic – Institut Pasteur
On its website, the Pasteur Institute warns: “The spread of infection among birds increases the likelihood of a new influenza virus emerging in the human population. In addition, like all type A influenza viruses, the H5N1 subtype has a high ability to mutate over time […]. The risk of the appearance of a new virus capable of being transmitted from person to person must be taken into consideration”.
The precautionary principle remains the best way to avoid the spread of the virus and such mutations, explains Jean Luc Guérin. This notably involves the slaughter of poultry on affected farms and the establishment of protection zones.