Absence of detection of highly pathogenic H5N1 in migratory waterfowl in southern France in 2005-2006.
During fall 2005, the rapid and wide spread of highly pathogenic (HP) H5N1 avian influenza viruses (AIV) outside Asia alerted European health authorities. Because of abnormal and recurrent field mortality, wild migratory birds were considered to be the main dispersing agent of the virus at an intercontinental scale. European wintering wetlands, such as the Camargue (Rhône delta, France), are identified as potential hot spots for the risk of introduction and transmission of bird-borne diseases. In this study, we investigated the role of migratory waterbirds (mainly ducks) in the spread of HP H5N1 viruses. We combined molecular analysis of living and freshly killed birds with population surveillance (aerial censuses and death surveillance). We sampled 1345 birds belonging to 17 waterbird species (3 orders) in the Camargue between September 2005 and March 2006. The prevalence of AIV was 1.8%. We did not detect HP H5N1 virus. Population censuses did not reveal any population decreases nor abnormal mortalities. We discuss, in the light of these results, the implication of wild migratory ducks in the arrival of HP H5N1 AIV in Europe.
Lebarbenchon
Camille
C
Station Biologique de la Tour du Valat, Le Sambuc, 13200 Arles, France. lebarbenchon@tourduvalat.org
van der Werf
Sylvie
S
Thomas
Frédéric
F
Aubin
Jean-Thierry
JT
Azebi
Saliha
S
Cuvelier
Frédérique
F
Jeannin
Patricia
P
Roca
Vanessa
V
Chang
Chung-Ming
CM
Kayser
Yves
Y
Roche
Benjamin
B
Guégan
Jean-François
JF
Renaud
François
F
Gauthier-Clerc
Michel
M
D025041:Animal Migration; D000818:Animals; D046090:Anseriformes / Q000821:virology*; D005243:Feces / Q000821:virology; D005602:France / Q000453:epidemiology; D053124:Influenza A Virus, H5N1 Subtype / Q000302:isolation & purification* / Q000472:pathogenicity; D005585:Influenza in Birds / Q000453:epidemiology* / Q000821:virology*