Swine influenza

Swine influenza is a notifiable disease

Under Queensland legislation, if you suspect the presence of this disease in pigs, you must report it to Biosecurity Queensland.

Call us on 13 25 23  or the Emergency Disease Watch Hotline  1800 675 888



Influenza viruses describe a large group of viruses that are classified as type A, B or C. Within this large group, different influenza viruses infect different species of animals including humans. Influenza viruses are usually 'specialised' to infect only one species of animal, though occasional cross infection to other species can occur. The swine influenza viruses belong to type A.


Swine influenza is a highly contagious acute respiratory disease of pigs. It is a notifiable disease under legislation and all suspect cases must be reported to Biosecurity Queensland on 13 25 23.

Where the disease occurs

Swine influenza occurs in most areas of the world where pigs are kept.

The disease in pigs

Outbreaks in pigs can occur year round, with an increased incidence in the colder months in temperate zones. This is a herd disease, with a large number of the pigs in a herd affected. The disease typically presents as an acute to chronic respiratory disease and infected pigs may show fever, anorexia, weight loss, coughing, sneezing, nasal discharge, and respiratory difficulty.

Infection can also occur with no clinical syndrome evident. Mortality is generally low (1-3%) and in the absence of complications, most affected pigs will recover in 5 to 7 days.

In Australia, these signs would be very obvious as the Australian pig herd has little immunity against swine influenza and would be susceptible to the disease.

How the disease spreads

The virus is primarily transmitted among pigs in close contact through nasal discharge and aerosols from sneezing and coughing. The main method of spread is through the movement of infected pigs.

The virus may also be spread from contaminated objects moving between infected and uninfected pigs.

Control of the disease in pigs

The detection of swine influenza in Australia is regarded as an emergency and every attempt will be made to eradicate the disease. National arrangements are already in place to support such a response.

In 2009 pig herds in Queensland, New South Wales and Victoria became infected with the influenza A (H1N1) 2009 virus, most likely due to spill-over from the human population. The national response program was activated and the virus was eradicated from the properties.

In other countries pigs are routinely vaccinated against swine influenza, but the vaccine is not registered for use in Australia.

Can people get the disease?

Influenza A viruses can infect a wide variety of animal species, including humans.

While it is recognised that swine influenza viruses do not usually infect humans, rare human infections have occurred. Similarly, it is well recognised that influenza viruses may be spread from humans to pigs.

People working in piggeries and those having frequent contact with pigs should consider personal influenza vaccination while remaining attentive to appropriate personal hygiene and biosecurity practices.

For information about swine influenza in people contact Queensland Health on 13 HEALTH.

Anyone who is in contact with pigs and experiences flu-like symptoms should contact their local doctor, population health unit or call 13HEALTH.

Further information