BACKGROUND Highly pathogenic avian influenza A (HPAI) H5N1 viruses have infected poultry and wild birds on three continents with more than 600 reported human cases (59% mortality) since 2003. Wild aquatic birds are the natural reservoir for avian influenza A viruses, and migratory birds have been documented with HPAI H5N1 virus infection. Since 2005, clade 2.2 HPAI H5N1 viruses have spread from...

There are many types of influenza viruses, which cause illness in a variety of birds and mammals. New strains are constantly evolving, causing seasonal influenza epidemics in humans. This article provides information about influenza and influenza viruses, and the three influenza pandemics of the twentieth century. Pandemic influenza is differentiated from avian influenza, which is a viral disea...

Avian influenza viruses produce mainly respiratory and intestinal diseases. Their relevance in the generation of pandemic strains has led to a large amount of research to understand their distribution in nature, as well as the relations that become established for the effective transmission among different hosts. Waterfowl have been recognized as their natural reservoir and they play an importa...

Surveillance for influenza A viruses in wild birds has increased substantially as part of efforts to control the global movement of highly pathogenic avian influenza A (H5N1) virus. Studies conducted in Egypt from 2003 to 2007 to monitor birds for H5N1 identified multiple subtypes of low pathogenicity avian influenza A viruses isolated primarily from migratory waterfowl collected in the Nile De...

UNLABELLED Influenza A viruses (IAVs) are maintained mainly in wild birds, and despite frequent spillover infections of avian IAVs into mammals, only a small number of viruses have become established in mammalian hosts. A new H3N2 canine influenza virus (CIV) of avian origin emerged in Asia in the mid-2000s and is now circulating in dog populations of China and South Korea, and possibly in Thai...

INTRODUCTION Avian influenza viruses circulate in bird populations, and it is important to maintain and uphold our knowledge of the viral strains that are currently of interest in this context. Here, we describe the use of hemagglutinin-pseudotype retroviruses based on highly pathogenic influenza viruses for the screening of avian sera for influenza A antibodies. Our aim was also to determine w...

Avian influenza A H5N1 viruses continue to spread globally among birds, resulting in occasional transmission of virus from infected poultry to humans. Probable human-to-human transmission has been documented rarely, but H5N1 viruses have not yet acquired the ability to transmit efficiently among humans, an essential property of a pandemic virus. The pandemics of 1957 and 1968 were caused by avi...

UNLABELLED Avian species are reservoirs of influenza A viruses and could harbor viruses with significant pandemic potential. We examined the antibody and cellular immune responses to influenza A viruses in field or laboratory workers with a spectrum of occupational exposure to avian species for evidence of zoonotic infections. We measured the seroprevalence and T cell responses among 95 individ...

Avian influenza is an infection caused by avian influenza (bird flu) viruses, which occur naturally among birds. Wild birds worldwide carry the viruses in their intestines, but usually do not get sick. However, avian influenza is very contagious among birds and can cause illness and death in some domesticated birds, including chickens, ducks, and turkeys. The virus can transmit from birds to hu...

Influenza A H10N7 virus with a hemagglutinin gene of North American origin was detected in Australian chickens and poultry abattoir workers in New South Wales, Australia, in 2010 and in chickens in Queensland, Australia, on a mixed chicken and domestic duck farm in 2012. We investigated their genomic origins by sequencing full and partial genomes of H10 viruses isolated from wild aquatic birds ...