Advanced Search | Help
28 September 2000
Seventy-nine reported sightings of dead sparrows have been received from the public, in response to an appeal for support in the investigation into sparrow deaths.
On Friday (22 September) MAF and DOC asked the public to report, to their local DOC office, sightings of groups of dead birds. This was in order to help the Ministry of Agriculture and Forestry determine the size of the problem, and enable bird samples to be obtained for testing. Prior to Friday, there had been eight reports of group bird deaths.
The numbers of dead sparrows sighted ranged from 1 to 400, but usually were in the "dozens." Information of the sighting has been collated and sent to MAF’s National Centre for Disease Investigation (NCDI), which is working in collaboration with DOC to obtain bird samples.
The largest number of reported sightings came from Canterbury with 49 calls, 13 of which involved groups of more than ten birds. Hastings and Taradale produced 13 sightings of dead birds, one of which was a large group of 50 dead birds. Wellington reported 20 sightings, but many of these were single sparrow deaths.
"We’ve received a number of calls of sightings of one dead bird, and although we appreciate the public's interest in this, the death of one bird is not that unusual, particularly during winter and early spring. What this investigation is focusing on is sightings of group deaths in sparrows, or other small birds such as waxeyes and riflemen" says Roger Poland, MAF Programme Co-ordinator, Surveillance.
Sparrow deaths have been reported in Northland, Gisborne, Hastings, Napier, New Plymouth, Hamilton, the Manawatu, Masterton, Wellington, Picton, Blenheim, North Canterbury, Christchurch, and Hokitika. Salmonella Typhimurium phage type 160 has been isolated in two cases to date, however there are test results pending from another 9 cases.
In addition to the two confirmed cases in sparrows, during the past eight weeks there have been a total of 15 confirmed cases of Salmonella Typhimurium phage type 160 in rabbits, dogs, cats, ducks, quail, deer, horses, cattle, and cockatoos. The location of these cases included Christchurch, Rangiora, Prebbleton, Selwyn and Kaikoura.
There have been no cases of salmonellosis reported in native birds so far. The Orana Park Kaka did not die from salmonellosis.
Salmonella can be transferred to humans and animals through contaminated faeces. As a precaution, people should not touch dead sparrows or their droppings, and should follow general good hygiene practises, such as washing hands before handling food. Symptoms of salmonellosis in people include diarrhoea and vomiting.
MAF and DOC are continuing to seek public support in its investigation, and are asking people to contact their local DOC office with information on sightings of dead birds.
A Salmonella fact sheet follows
For further information call:
Dr Roger Poland, MAF Programme Co-ordinator, Surveillance. Telephone: N/A20
Gita Parsot, MAF Communications. Telephone: N/A
What is Salmonella?
Salmonellosisa is a group of diseases rather than a single disease. It is caused by Salmonella bacteria. The bacteria are common in nature, but occasionally a strain will infect birds (or other animals) in the form of an "outbreak". The disease causes a gut infection, and in wild populations of birds leads to a loss of condition in the bird, possibly convulsions, and death. It is passed on to other birds and animals through the faeces (droppings) of infected birds, or through eating uncooked parts of the infected animal.
We are finding that the sparrows in this outbreak are infected with Salmonella Ttyphimurium, a particular strain of Salmonella.
How have sparrows contracted salmonella?
The outbreak may have come from Salmonella bacteria that are naturally present in sparrow populations at low levels. Like many species (including humans) some sparrows are outwardly healthy carriers of salmonella. Carrier birds and animals shed salmonellae in their droppings. Perching birds like sparrows are believed to host outbreaks because they feed together and there are numerous chances for an infected bird to pass the disease onto several others causing a very rapid spread.
At the start of an epidemic, the number of Salmonella bacteria shed by infected birds that get sick is large, and these sick birds provide the main source of infection for other birds, animals and people. Heavily infected birds usually die and they continue to shed the bacteria for several days before they die. Those birds that recover may continue to shed Salmonella bacteria in their droppings for weeks or months.
We are not sure why this particular outbreak of salmonella has happened, which is why we have asked the public for report sightings of groups of dead birds.
Are other animals and humans susceptible to salmonella?
The host species susceptibility to salmonellae depends on the species of salmonella. Salmonella Ttyphimurium infects a wide range of animal and bird species as well as people. Pet cats and dogs are susceptible to Salmonella Ttyphimurium. If hens become infected with Salmonella Ttyphimurium they can pass it on via faecal contamination of eggs at the time eggs are laid. The eggs themselves may also be infected. As cooking kills Salmonella bacteria, well-cooked eggs and food are safe to eat.
How likely is my cat to get sick from eating infected birds?
Cats that eat sick or dead birds can be infected. Discourage your cat from catching birds where you can. If your cat is obviously sick, contact a vet. Currently, we have not had reports of a significant increase in cats with Salmonella poisoning in the places where dead birds have been found.
What about native birds?
We expect native birds to be susceptible to the disease. The Department of Conservation is collecting samples of sparrows to assist MAF in finding out how widespread the disease is.
What is an infectious dose?
The infectious dose required to establish salmonella in people, animals, and birds varies with the individual concerned. Not all animals, people or birds exposed to Salmonella will get sick - the number of bacteria you ingest has a significant influence on whether you become ill.
Reporting on and collecting samples of dead birds
Please phone your nearest Department of Conservation office to report any large numbers of dead birds. DOC staff will record your details, and may ask if you can drop off a sample of the dead birds.
If you are collecting birds to hand in for sampling, use a plastic bag over your hands when picking up the birds. Enclose the birds in plastic bags, and wash your hands thoroughly afterwards and before eating or preparing food.
Handing in birds that have only just died is best, but Salmonella bacteria can be recovered from birds that have been dead for a day or two. Freezing dead birds is fine, particularly if they’ve been dead for more than 12 hours. But do not put them in a freezer containing food because of the risk of food being contaminated.
Precautions at home and in business
Wash hands before preparing food and before eating. Check that your water supplies are safely treated. If you are on roof-water in an area where birds are dying, it is best to boil the water before drinking it until the outbreak passes.
Should I continue to feed the birds?
The stress of starvation/ lack of food over winter is a significant factor in increasing the susceptibility of birds to salmonellosis. However feeding them does bring lots of birds into close contact with each other, and this may actually help spread the disease. It is probably best not to feed the birds because of the current salmonella outbreak, and also there is more food around for birds as the weather becomes warmer.
Is this a new strain of Salmonella?
Cases of this type have been observed for several years now. There is some evidence of increasing incidence with time, which is why we are asking for help in further investigation and clarification of the extent of this outbreak.
This outbreak may be a slightly different strain of the bacteria from that usually found in the sparrows, but further research by veterinarians and scientists will be needed to find that out.