Influenza Surveillance in Wild Birds in Eastern Europe, the Middle East, and Africa: Preliminary Results from an Ongoing FAO-led Survey

In the context of the spread of highly pathogenic avian influenza (HPAI) H5N1 virus through Eurasia during 2005, a surveillance study of wild birds was launched in early 2006 within the framework of regional Technical Cooperation Programmes of Food and Agriculture Organization in several countries of eastern Europe, the Middle East, and Africa. From midJanuary to mid-May 2006, field campaigns were conducted in 14 countries, including recently infected countries. In total, 5,256 samples were collected in large wetland areas where Eurasian and Afro-tropical waterbirds congregate. The overall prevalence of avian influenza viruses detected by RT-PCR was 3.3%, with no positivity for HPAI H5N1 virus. Five distinct virus isolates were obtained from the RT-PCR–positive samples. Low pathogenic avian influenza (LPAI) viruses were detected and isolated in both Eurasian and Afro-tropical bird species, indicating that low pathogenic viruses were circulating in Africa during the northern winter. These findings reveal that LPAI virus persists in wild birds in subtropical environments and support the hypothesis that avian influenza viruses could be perpetuated in wild birds throughout the year, including in Palearctic waterbirds wintering in sub-Saharan Africa before their northward spring migration.