TOUR DU VALAT
A research centre for the conservation of Mediterranean wetlands
Topics
Matter of vocabulary
One or several avian influenzas?
It is in fact more correct to talk about multiple avian influenzas, as the Influenza A virus exists in many different forms, called “strains”. Every year in France, for millennia, these strains have spread among wild and domestic birds. Many different strains of human influenza spread the same way.
The H5N1 virus
Normally, avian influenza viruses spread only among birds, and human influenza viruses spread only among humans. The Asian flu virus is the highly pathogenic H5N1 strain, which we have recently heard a lot about. Of particular concern is the fact that it can spread from bird to human. Nevertheless, this occurrence is very rare: less than 200 deaths have been recorded worldwide during the last five years. Therefore, the risks have to be put in perspective.
The highly pathogenic Asian H5N1 virus has caused important economic damages to poultry farming but rarely caused human death. It is, above all, a veterinary health problem. Nevertheless, the H5N1 virus can possibly mutate and obtain the ability to pass from man to man, therefore enabling it to be quickly spread around the world. This phenomenon would then be called an Influenza pandemic. It is impossible at the moment to predict if this mutant virus will appear and what exactly it would look like. It is therefore impossible to create the specific vaccine. If the mutation ever happens, this new virus may be less virulent and cause little death among humans.
