TOUR DU VALAT
A research centre for the conservation of Mediterranean wetlands
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Is the Camargue a risk-prone area ?
Where does the risk come from?
The Camargue is often mentioned as a risk-prone area for the H5N1 type of avian Influenza. This is due to the fact that it is a crossroad for migrating birds. If wild birds, notably migrating birds, are the favourite target of institutions, numerous elements are presented as favourable to other causes of spread of the disease, such as the industrialization of the poultry farming, which is particularly affected by the appearance of virulent strains and has generated changes in the virus. The Tour du Valat team put forward these explanations in an article which came out in the journal Ibis in spring 2007. The H5N1 virus was detected for the first time in domestic birds in South-East China in November 1996. Since then, it has spread throughout the major part of Asia and Europe. As a reminder, the highly pathogenic H5N1 strain came originally from domestic farms. Since mid 2005, wild birds have been blamed for spreading of the virus out of Asia. Yet the virus path does not fit with the main migratory routes. They seem to better represent the commercial trajectories taken by poultry traffic, for which sanitary controls are not reliable.
During the former epizootics which were linked to the highly pathogenic H5 and H7 avian influenza strains, it was clearly shown that the spreading of the virus was due to human activities, and particularly movement of poultry. Though the virus can be moved a short distance by wild birds, it has never been proved that transmission over a long distance by seasonal migration was effective. Thousands of tests have recently been made on wild birds in Europe and have not found the presence of this virus to date. Therefore, although great media coverage is given to different cases of infected wild birds, they are still insignificant compared to the millions of healthy wild birds crossing or living in our countries.
