Wetenschappelijk artikelEpidemiology of Influenza A Virus among Black-headed Gulls, the Netherlands

We sampled 7,511 black-headed gulls for influenza virus in the Netherlands during 2006–2010 and found that subtypes H13 and H16 caused annual epidemics in fledglings on colony sites. Our findings validate targeted surveillance of wild waterbirds and clarify underlying factors for influenza virus emergence in other species. Keywords: influenza A virus, viruses, influenza, avian influenza, Charadriiformes, epidemics, virulence, disease reservoirs, zoonoses, black-headed gulls, the Netherlands Wild waterbirds of the orders Anseriformes (ducks, geese, swans) and Charadriiformes (gulls, terns, shore birds) are the ultimate source of influenza A viruses for domestic birds and mammals, including humans (1). Knowledge of the epidemiology of these avian influenza viruses (AIVs) among wild waterbirds is necessary to improve surveillance and better clarify underlying factors in host-switching of AIV. Epidemiology of AIV in wild waterbirds has been studied mainly among ducks (order Anseriformes) (2) but is poorly known among gulls, despite their abundance and close association with humans (3). Therefore, we studied the epidemiology of AIV in one of the most common gull species in western Europe, the black-headed gull (Chroicocephalus ridibundus).