Faced with the recurrence of these outbreaks of avian influenza, it is necessary to ask the question of the origin of these viruses and the possible measures which would make it possible to reduce the risk of their appearance and dissemination in farms. The voice of research, every day in your emails, for free. What is bird flu? The flu is caused by influenza viruses.
These viruses are composed only of RNA , which has the consequence that their rate of mutation is extremely rapid. One of the consequences of this rapid evolution is that their diversity is particularly important. In order to be able to classify this diversity, the different viruses have been categorized according to their differences at the level of two glycoproteins : Hemagglutinin (H) which is used phone number list by the virus to enter the cell of the infected individual; and Neuraminidase (N) which is used to get out of it. The combination of the two gives us the subtype: for example, H5N1 for avian flu or H1N1 for the recent human flu pandemic.
Today, 18 types of Hemagglutinin and 9 types of Neuraminidase have been identified. Nevertheless, all these subtypes are not necessarily very pathogenic, that is to say responsible for a high mortality rate for infected birds (some H5N1 viruses can indeed be weakly pathogenic). The virulence of the virus is in fact linked to a specific genetic mutation on the hemagglutinin (H) of the virus, which is most frequently observed in H5Nx type viruses. It is these highly pathogenic viruses (H5N1, H5N2 and H5N9) that have been detected in the South-West of France. Wild ducks.