Influenza pandemics, defined as global outbreaks of the disease due to viruses with new antigenic subtypes, have exacted high death tolls from human populations. The last two pandemics were caused by hybrid viruses, or reassortants, that harbored a combination of avian and human viral genes. Avian influenza viruses are therefore key contributors to the emergence of human influenza pandemics. In...

Highly pathogenic avian influenza virus A/H5N1 has been reported in 11 African countries. Migratory waterbirds have the potential of introducing A/H5N1 into east Africa through the Rift Valley of Kenya. We present the results of a wild bird surveillance system for A/H5N1 and other avian influenza viruses based on avian fecal sampling in Kenya. We collected 2630 fecal samples in 2008. Viral RNA ...

human infection with avian influenza a h7n9 virus has emerged in china with high morbidity rates. patients usually present with severe and rapidly progressive pneumonia. therefore, radiological findings are important to diagnose and evaluate disease severity. the clinical characteristics of three new cases of h7n9 virus infection were analyzed, especially the radiological findings, and previous...

The adaptation of H5N1 avian influenza viruses to human poses a great threat to public health. Previous studies indicate the adaptive mutations in viral polymerase of avian influenza viruses are major contributors in overcoming the host species barrier, with the majority of mammalian adaptive mutations occurring in the PB2 protein. However, the adaptive mutations in the PA protein of the H5N1 a...

Many viruses, including human influenza A virus, have developed strategies for counteracting the host type I interferon (IFN) response. We have explored whether avian influenza viruses were less capable of combating the type I IFN response in mammalian cells, as this might be a determinant of host range restriction. A panel of avian influenza viruses isolated between 1927 and 1997 was assembled...

Human infections with H5, H7, and H9 avian influenza viruses are well documented. Exposure to poultry is the most important risk factor for humans becoming infected with these viruses. Data on human infection with other low pathogenicity avian influenza viruses is sparse but suggests that such infections may occur. Lebanon is a Mediterranean country lying under two major migratory birds flyways...

We evaluated the potential for avian-to-human transmission of low pathogenic avian influenza (LPAI) and highly pathogenic avian influenza (HPAI) H7N1 and LPAI H7N3 viruses that were responsible for several outbreaks of influenza in poultry in Italy between 1999 and 2003. A serological survey of poultry workers was conducted by use of a combination of methods. Evidence of anti-H7 antibodies was ...

Continuous circulation of influenza A(H5N1) virus among poultry in Egypt has created an epicenter in which the viruses evolve into newer subclades and continue to cause disease in humans. To detect influenza viruses in Egypt, since 2009 we have actively surveyed various regions and poultry production sectors. From August 2010 through January 2013, >11,000 swab samples were collected; 10% were p...

Avian influenza viruses may cause mild or severe disease in birds. There have been five recorded outbreaks of highly pathogenic avian influenza in birds in Australia, all of which were caused by the H7 subtype. These were quickly controlled and similar coordinated responses are expected for possible future outbreaks of avian influenza. Migratory birds are not regarded as the source of these out...

Avian influenza A viruses from Asia are recognized as the source of genes that reassorted with human viral genes to generate the Asian/57 (H2N2) and Hong Kong/68 (H3N2) pandemic strains earlier in this century. Here we report the genetic analysis of avian influenza A H1N1 viruses recently isolated from pigs in southern China, a host suspected to generate new pandemic strains through gene reasso...