Avian adenovirus

Aviadenoviruses are adenoviruses that affect birds - particularly chickens, ducks, geese, turkeys and pheasants. There are currently eight species in this genus including the type species Fowl aviadenovirus A. Viruses in this genus cause specific disease syndromes such as Quail Bronchitis (QB), Egg Drop Syndrome (EDS), Haemorrhagic Enteritis (HE), Pheasant Marble Spleen Disease (MSD), Falcon adenovirus A and Inclusion Body Hepatitis (IBH). Avian adenoviruses have a worldwide distribution and it is common to find multiple species on a single farm. The most common serogroups are serogroup 1, 2 and 3. No evidence of transmission from birds to humans has been identified. The virus is mainly spread horizontally by the oro-fecal route, but vertical transmission can occur in serogroup 1. Once it has infected the bird the virus may remain latent until a period of stress, when it may then cause clinical disease. Infections are normally subclinical, however clinical disease can occur - especially in young birds as maternal antibody levels begin to wane.