Abstract and Introduction
Phylogenetic analysis of influenza A viruses (H5N1) isolated from Kuwait in 2007 show that (H5N1) sublineage clade 2.2 viruses continue to spread across Europe, Africa, and the Middle East. Virus isolates were most closely related to isolates from central Asia and were likely vectored by migratory birds.
Highly pathogenic avian influenza (HPAI) virus (H5N1) has been endemic in poultry in Asia since 2003.[1,2] From 2002 through 2005, influenza virus (H5N1) has also been sporadically isolated from dead wild birds in Hong Kong Special Administrative Region, People's Republic of China; however, these birds were considered dead-end hosts of viruses acquired from poultry.[3,4] In April 2005, an influenza (H5N1) outbreak was detected in bar-headed geese (Anser indicus) at Qinghai Lake in western China.[5] Following this outbreak, the Qinghai-like (clade 2.2) influenza virus (H5N1) lineage was detected in wild birds and domestic poultry in countries in central Asia, the Middle East, Europe, and Africa.[6,7,8,9,10] The source of these introductions, while still debated, is likely through bird migration, although in some instances, the role of the poultry trade has not been ruled out.[6,7,8,9,10,11,12]
The clade 2.2 influenza (H5N1) viruses continue to be detected throughout these regions; 69 human cases with 31 deaths were reported from Azerbaijan, Djibouti, Egypt, Iraq, Nigeria, Pakistan, and Turkey from January 2006 through December 2007.[13] Since early 2007, the Qinghai-like influenza (H5N1) lineage has continued its geographic spread and has been reported from more than 40 countries in Eurasia and Africa.[6] The continued detection of these viruses in Africa, Europe, and the Middle East from mid-2006 onward suggests that the virus may now be endemic in these regions.
Emerging Infectious Diseases. 2008;14(6):958 © 2008 Centers for Disease Control and Prevention (CDC)
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