Brucellosis is an infection that can be transmitted to humans from some animals such as cows, sheep, goats and pigs. While this disease is common in many parts of the world, it is rare in Australia. Cases in NSW usually result from contact with feral pigs or from consuming unpasteurized dairy products while overseas.
Brucellosis is an infection caused by the bacterium Brucella that is spread to humans from infected animals. Although animals are infected worldwide brucellosis is well controlled in most developed countries including Australia. Rarely, brucellosis infections occur in humans.
Different types of Brucella bacteria usually infect different animals. There are five types of Brucella bacteria that that are known to cause brucellosis in humans. The following three are of particular importance to Australian residents and travellers:
Although Brucella ovis is present in many sheep flocks across NSW, it is not known to cause human disease.
Brucellosis typically begins with a flu-like illness. This may include fever, headache, weakness, drenching sweats, chills, weight loss, joint and muscle pain, and generalised aches. Inflammation of the liver and spleen, and gastrointestinal or respiratory symptoms may also occur. In males, the testicles may become inflamed. Rarely, the valves inside the heart may become infected and this can be fatal.
The symptoms usually start 5-60 days after a person has been infected.
The infection typically lasts for days or months but can occasionally last for a year or more and may recur. Disease may be mild and some people get no symptoms of infection.
Pregnant women and their babies are at risk of developing severe disease. If left untreated, infection may cause birth defects, spontaneous abortion or fetal death.
In Australia, people may become infected through:
Additionally travellers to countries where brucellosis is more common may become infected through consuming unpasteurised dairy products (such as raw milk and unpasteurised cheeses from sheep, goats, cows or camels) or undercooked meat from an infected animal.
Uncommonly, the bacteria can be inhaled and cause disease, such as in laboratory workers who work with Brucella cultures.
The infection is very rarely passed from one human to another.
People at higher risk include:
Feral pig hunters and others who are in contact with feral pigs should follow the precautions outlined in the Brucellosis and Feral Pig Hunting fact sheet to protect themselves protect themselves, their family and dogs against brucellosis and other common diseases transmitted from animals.
Thoroughly cook meat from feral pigs (and other game) before eating – freezing, smoking, drying and pickling do not kill the bacteria that cause brucellosis.
Those vulnerable to severe disease (such as pregnant women) should avoid all contact with feral pigs, hunting activities and pig hunting dogs.
If your dog has been diagnosed with brucellosis, follow the recommendations outlined in the Brucellosis in Dogs Information Sheet from the NSW Department of Primary Industries (DPI) to prevent spreading the infection to humans and other domestic animals.
Travellers to countries where brucellosis is more common should:
If brucellosis is suspected, a doctor will usually collect two blood samples, two or more weeks apart to check antibodies against the bacteria. This test cannot reliably differentiate between the different Brucella species. The doctor may also take samples of fluid or tissue from affected body parts to culture (grow) the bacteria.
Effective treatment usually involves a combination of antibiotics for at least six weeks. Occasionally, antibiotics may need to continue for months. Despite treatment, brucellosis can recur. If symptoms persist, consult your medical practitioner.
Brucellosis infection in humans is a notifiable medical condition in NSW. Local public health units will contact those infected to try and identify the likely source of infection. If brucellosis is acquired in NSW or if a domestic animal is infected, the NSW DPI may be consulted to help control the spread of infection in animal populations.
For further information about brucellosis in humans:
For further information about brucellosis in animals, see the NSW DPI websites on: