Avian flu virus H5N1 and pigeons: the facts.
The following information was compiled by Brad Turner, a member of Australian Naptional Pigeon Association, the Queensland Pigeon Fanciers Society Inc (QPFS) and the Ipswich Pigeon Specialist Club Inc (IPSC).
Mr. Turner's contact information is available by request.
There are thousands of different kinds of avian influenza (bird flu) viruses, including H5N1, which is known as a Type A virus.
Wild birds worldwide carry the viruses in their intestines, but usually do not get sick from them. However, bird flu is very contagious among birds and can make some domesticated birds, including chickens, ducks and turkeys, very sick and even kill them.
Bird flu viruses do not usually infect humans, but Type A viruses have been recovered from humans, pigs and horses, and occasionally from birds and other mammals. Humans more usually contract Type B or C viruses.
So far, the spread of H5N1 virus from person to person has been rare and the spread has not continued beyond one person. However, because all influenza viruses have the ability to change or mutate, scientists are concerned that the virus might one day be able to infect humans and spread easily from one person to another.
Because these viruses do not commonly infect humans, there is little or no immune protection against them in the human population. If the H5N1 virus was able to infect people and spread easily from person to person an influenza pandemic could begin.
Potential risks from pigeons:
In late 1992, antibodies to bird flu were found in blood samples from a commercial flock of turkeys in northeastern USA. Antibodies are protective substances that are produced by the body to defend against infection. Investigation showed that there was a possible association between this flock and live bird markets, and a virus designated H5N2 was isolated from birds in one location.
Public poultry markets, shows and exhibitions were quarantined and premises on which the virus was found were isolated and depopulated. Authorities in a number of US States banned pigeon racing.
A major survey and testing regime was undertaken among wild and free-flying domestic ducks and geese, wild or free-flying domestic birds closely associated with poultry farms, poultry manure or poultry carcasses, mice and rats found inside and around houses containing infected poultry and wild birds of any species reported sick or dead in the quarantine zone.
Included in this survey were 473 pigeons, 92.6 percent obtained from known infected farms, 81 pigeon feet (all from flu-affected premises) and seven mourning doves.
None of the 4132 samples was positive for the bird flu virus, nor were others taken from a further 433 pigeons in the quarantine zone. Experimental attempts to infect pigeons with this strain did not result in any growth of the virus in the birds, or result in the production of any antibodies.
Another study published in 1996 into the susceptibility of pigeons to avian flu found that groups of pigeons innoculated with two strains of deadly virus or two strains of a non-fatal virus remained healthy for the entire three-week trial period, nor did the birds shed the virus, or develop antibodies to the disease – further evidence that pigeons are not a factor in the spread of this disease.
Additionally, experimental work in 2001-2002 in Hong Kong showed that pigeons infected with H5N1 did not develop signs of the disease and did not have detectable changes to this disease in their tissues. The virus could not be re-isolated from swabs taken from the pigeons.
In summary, there is a very slight chance that if a pigeon returning from a race (or any wild bird) dropped into a poultry farm in which the chickens were infected, it could pick up the bird flu virus on its feet while walking among droppings and then, in theory, spread the disease by landing in another poultry farm.
However, as noted earlier, the feet of pigeons collected in the 1990s were examined for bird flu virus and all were found to be negative.
Sources for the previous information:
Avian Influenza and Pigeons, by Dr Gordon A Chalmers, Alberta, Canada.
US Department of Health and Human Services, Centers for Disease Control and Prevention. (October 2005)
An Australian expert’s view:
Beside being Queensland’s only registered specialist in bird medicine, Dr Bob Doneley (BVSc FACVSc (Avian Health) is an adjunct Professor in the University of Queensland’s School of Veterinary Science.
Dr Doneley has a veterinary practice in West Toowoomba near Brisbane, and is also a parrot breeder and fancier.
Here is what he says about the likelihood of a human being infected by being in contact with a pigeon or a parrot.
“You're more likely to have a light plane hit by a meteor and fall on your head than somebody getting bird flu off their cockatiel.”
Dr Doneley said the public were paranoid about catching bird flu off their neighbours' backyard pets because the media had “played up” the virus.
He said his surgery had been swamped with inquiries from panicked bird owners and neighbours about their pet parrots, finches and budgies.
“We're getting three or four phone calls a day from people wanting to know if they should sell their house because their neighbours have got birds.
“Although pigeons have been reported to be carriers of this virus, in the broad scheme of things they are considered relatively unimportant.
“Racing pigeons could be considered as a possible vector in the event of an outbreak – and IF that did occur, I am sure the racing would be stopped until things settle down.
“Show birds are no greater a threat than my parrots.
“All this hoopla about pigeons being 'flying rats' is just rubbish.
“Yes, I see some interesting pathology in pigeons, especially in racing birds in poor standard lofts, but overall they are no worse, and no better, than other birds kept in similar conditions.”
The Australian experience:
Pigeon flyers and fanciers recently found themselves caught up in the furore surrounding H5N1 when three birds in an import shipment of 102 racing pigeons from Canada were found to have antibodies to a strain of bird flu.
The Australian Government responded by asking the Canadian authorities to explain how the birds were allowed to be exported given the Australian Quarantine Inspection Service (AQIS) protocols (see section below on Importing live birds into Australia), and importations were also banned.
By the time the Canadians has assured the Australian authorities their country was free of H5N1 and did not send birds with this strain here, it had been discovered that the three birds had another form of the flu.
Import bans were then lifted and the rest of the shipment released to its new owner.
Nevertheless, the incident started ill-informed people looking at pigeon flyers and fanciers with considerable suspicion.
Below are excerpts from statements from two bodies representing the pigeon hobby.
From Bob Grant, President, the Australian National Pigeon Association:
Mr Grant, whose organisation represents around 400 breeders of show or fancy pigeons nationwide, said his members fully endorsed the AQIS decision to destroy the three pigeons from Canada.
"Not only does ANPA agree with this move, our members worked closely with AQIS in devising such protocols when the importation of birds from overseas started in the 1990s," Mr Grant said.
"Many of our members have been involved in shipments of pigeons into Australia since that time and are perfectly satisfied that the system is safe. These latest events certainly bear this out."
Mr Grant said he and ANPA executives across Australia had been contacted by many members in recent weeks who were concerned about the impact that misinformation about pigeons and the avian influenza virus would have on their hobby
"Some of these people have kept pigeons for 40 or 50 years and are worried that the publicity surrounding H5N1 will unduly concern people living nearby, or with whom they have contact," he said.
"I can assure the public that if there were any evidence to support a theory that our pigeons could in any way cause harm to humans, we would be the first to support any actions AQIS might recommend.
From the Executive Committee of the Queensland Racing Pigeon Federation Incorporated (QRPF)
Three birds (from Canada) tested positive to a Class 5 antibody – this means that at some time in the past these three birds had been exposed to some type of virus and had developed antibodies.
It is important to note that the birds in question did not test positive to H5N1.
We believe that these three birds may have received an inoculation prior to departure from Canada and that the birds then developed antibodies in response to this vaccination.
H5N1 is not present in Australia and the QRPF Inc applauds and supports AQIS in their testing procedures and protocols.
Despite some media suggestions to the contrary, racing pigeons do not pose a threat to public health and safety.
The QRPF Inc has very strict guidelines for the keeping of racing pigeons and these guidelines cover every aspect of the sport including health management of birds and “good neighbour” policies.
The QRPF Inc supports the eradication of “feral pigeons” from our community and is very aware of the damage that these feral strains can cause to buildings and property.
We are also very aware of the damage that these feral strains can and do have on the reputation of our racing pigeons within the wider community.
Very occasionally racing pigeons may stray from their home loft but these birds do not survive long in a wild state – they do not possess the necessary skills.
Importing live birds into Australia
Pigeons from the approved countries of the United States, Canada, the United Kingdom and France, and pet birds (from New Zealand only), are the only live birds that can be imported into Australia.
To be eligible for export to Australia, pigeons must be captive bred and resident in the source flock for six months prior to pre-export quarantine (PEQ). Birds must also be permanently identified by leg bands or microchips.
PEQ of 55 days must be undertaken in a facility approved by the appropriate authority in the exporting country. Birds are held in isolation, treated for parasites and tested for salmonella, avian influenza, Newcastle disease, eastern equine encephalomyelitis, West Nile virus and paramyxovirus.
Imported pigeons undergo 35 days post-arrival quarantine (PAQ) at AQIS’s high-security avian facility in Melbourne.
During PAQ the birds undergo further testing.
Disease-free sentinel chickens are located with the flock: these birds are highly susceptible to disease, and would become clinically ill if there were viruses circulating in the imported population. Sentinel birds are also tested for disease.
Australia imported 363 pigeons in 2004 and 455 pigeons in 2005.
Pet birds are permitted from New Zealand because NZ is free from bird diseases of concern to Australia. Only household pet birds whose owners are moving from New Zealand to take up residency in Australia are eligible.