Avian influenza in North and South America, the Caribbean, and Australia, 2006-2008

Between 2006 and 2008, only one outbreak of highly pathogenic notifiable avian influenza (AI) was reported from the Americas, the Caribbean, and Australia. The outbreak, caused by H7N3, occurred in September 2007 in a multiage broiler breeder facility (approximately 49,000 birds) near Regina Beach in southern Saskatchewan, Canada. The disease was confined to a single farm; the farm was depopulated. All other reports of infections in poultry or wild birds involved low pathogenicity AI viruses. A notable event that occurred during the 3-yr period was the spread of low pathogenicity notifiable AI (LPNAI) H5N2 (Mexican lineage) into the Caribbean countries of the Dominican Republic and Haiti in 2007 and 2008, respectively, representing the first detection of AI reported in these countries. Mexico reported that the LPNAI H5N2 virus continued to circulate in the central regions of the country, and a total of 49 isolations were made from 12 states between 2006 and 2008. Also, during this period there was a significant increase in AI surveillance in many countries throughout the Americas, the Caribbean, and Australia, resulting in the detection of AI subtypes H1 through H12 and N1 through N9 in domestic bird species (chickens, turkeys, guinea fowl, upland game birds, and ducks/geese). The United States was the only one of these countries that reported detections of LPNAI (H5 or H7) infections in commercial poultry: one in chickens (H7N3, 2007), two in turkeys (H5N1 and H5N2, 2007), and one in pheasants (H5N8, 2008). Detections of AI viruses in wild birds between 2006 and 2008 were reported from North America (Canada and the United States), South America (Bolivia, Argentina, Chile, and Brazil), and Australia.