In domestic animals, Brucella bacterium typically cause uterine and testicular infections. As such, brucellosis classically presents with infertility including poor conception rates, spontaneous abortions and palpable changes to testicles. While many animals will be otherwise unaffected, some animals may also appear unwell and with fever, lethargy, loss of appetite, enlarged lymph nodes and occasionally blood in the urine. Infections in bones and joints may cause lameness or pain on examination (especially of the spine).

If you suspect Brucella abortus infection in cattle, you must immediately notify an authorised officer by calling either LLS or the EAD Hotline.

Contact your Public Health Unit of their Local Health District on 1300 066 055 to report a potential human exposure to Brucella abortus.

You should isolate any animals displaying signs and ensure contact with feral animals is prevented.

When handling potentially infected animals or contaminated products, protective equipment including gloves, a mask and eye protection should be worn. A non-permeable dressing should be applied to any open wounds and hands and arms should be washed with soapy water following handling. All potentially contaminated surfaces should be disinfected.

If you suspect brucellosis, you should not move any animals off your property until test results are available.

Your veterinarian will collect samples to submit for testing. In NSW, most Brucella testing occurs on blood. A single definitive test is not available – generally two tests are used to identify evidence of exposure of the animal to Brucella bacteria. Diagnosis is usually based on a combination of history, clinical signs and lab results.

Blood tests will be reported as positive, inconclusive or negative. Animals with inconclusive results should be retested in 6 weeks.

For species of Brucella not native to Australia (Brucella canis, melitensis and abortus), follow-up testing of blood samples would be undertaken at the Australian Centre for Disease Preparedness (ACDP). Repeat samples or more invasive samples (potentially requiring desexing or euthanasia of the animal) may need to be collected as part of an emergency disease investigation.

Brucella is generally spread via:

• Mating (either natural or following artificial insemination with infected semen)
• Direct contact with tissues or blood from an infected animal
• Consumption of raw or undercooked infected meat or other feed products that have become contaminated with the bacteria.
• Contaminated equipment and clothing.

Brucella species can survive for months under ideal conditions (low temperature, high humidity and no sunlight).

Some animals will completely recover from infection; however, many will remain persistently infected and will intermittently present an ongoing risk of spread. These animals may not show any clinical signs an infection may therefore be inadvertently bought in. Purchasing animals from accredited sources or examining males prior to introduction to the flock/herd is important in managing spread.

Does Brucellosis affect people?

There are five types of Brucella bacteria that that are known to cause brucellosis in humans. Three are of particular importance to Australian residents and travellers: B. suis, B. melitensis and B. abortus.

As B. melitensis and B. abortus are not native to Australia, domestically acquired infections are extremely unlikely but may occur in returned travellers or potentially from consumption of imported food.

For more information on human Brucellosis please see the NSW Health factsheet

Contact your Public Health Unit of their Local Health District on 1300 066 055 to report a potential exposure and for further advice on managing the spread risk.