A few avian influenza viruses have been shown to also infect humans, but these strains do not spread easily from birds to humans. Effectively all human infections have come from contact with infected birds and no significant transmission between humans has been confirmed.
All influenza viruses ever found in birds have been influenza “Type A” viruses. Many different subtypes and strains occur, which have variable
abilities to make birds ill. These subtypes are given names labelled with “H” and “N”, to reflect the genetic makeup of the virus and its ability to invade the birds’ cells. Some avian influenza viruses circulate naturally in wild birds, generally with little effect. When these viruses get into poultry (eg chickens, geese, quail), some are highly pathogenic and kill large numbers of birds.
Wild birds would not ordinarily present a threat to human health. The main threat to public health lies in a human “pandemic” of influenza that may have its origin in a bird. The virus will then be adapted to humans and unlikely to affect birds. Such an adaptation is highly unlikely to occur in Australia and would be brought here by the movement of humans rather than birds.
The take home message is a human pandemic virus, if it were to arise, would come to Australia with a human and would not involve poultry.
Original author: Ron Glanville, QDPI&F