Brucellosis

About brucellosis

Brucellosis is an infection caused by the Brucella species of bacteria. These bacteria can be transmitted to humans via contact with infected animals and their products.

Brucella suis infects feral pigs in some parts of Australia – other animals can become infected if they share an environment with feral pigs.

Three other species of the bacteria (Brucella canis, Brucella abortus and Brucella melitensis) do not normally occur in Australia but may be acquired overseas.

Symptoms of brucellosis

Brucellosis usually begins with a flu-like illness, and may include symptoms like:

• fever
• sweats
• malaise
• headache
• anorexia
• joint and muscle pain, and fatigue
• depression.

These symptoms may resolve completely, reoccur, or persist for an extended period. Some infected individuals may experience no symptoms, or only mild symptoms.

Brucellosis can cause inflammation of the liver and/or spleen, joints (arthritis), respiratory system, and the testicles and scrotum. Rarely, the heart can become infected, which can be fatal if left untreated.

Pregnant women and their unborn babies are at higher risk of severe disease. Early diagnosis and treatment of brucellosis in pregnant women can be lifesaving for their unborn child.

Transmission of brucellosis

People become infected with brucellosis through contact with infected animals and their products.

In Australia, infected animals are most likely to be feral pigs, however a range of domestic and wild animals may be infected in other countries.

The bacteria can enter the body through:

• Wounds in the skin and/or mucous membranes that have contact with infected animals (infected tissues and/or excretions, such as meat, offal, birth products, blood, urine and vaginal discharges). This is the most common route of transmission for locally acquired infections, typically in pig hunters. Pig hunting dogs can also become infected and are a potential source of infection.
• Consumption of unpasteurised dairy products and undercooked meat from infected animals. This is most common in infections that have been acquired overseas but may occur locally in people who consume meat from wild pigs.
• In rare cases, breathing in the bacteria – this could potentially occur in a laboratory setting. Person-to-person transmission is very rare.

People at risk of contracting brucellosis

People at higher risk of contracting brucellosis include:

• Travellers to or migrants from areas where brucellosis is common in animal populations, such as India, central Asia, the Middle East, and regions in the Mediterranean, Africa and South America.
• People who consume unpasteurised milk and/or undercooked meat products, typically whilst travelling overseas.
• People who handle or have contact with animals and/or their excretions and tissues. This includes farmers, abattoir workers, veterinarians, and pig hunters.
• People working with Brucella bacterial cultures (such as laboratory workers).
• Pregnant women and their unborn babies are at higher risk of severe disease.

Diagnosis of brucellosis

Brucellosis is usually diagnosed through the detection of a rise in antibodies against the bacteria, via 2 blood tests taken at least 2 weeks apart.

Brucellosis can also be diagnosed through the culture of the bacteria from samples taken by a doctor.

Treatment for brucellosis

Early diagnosis and treatment for brucellosis are important for limiting the length of illness and preventing further complications.

Brucellosis is treated via a course of antibiotics that is prescribed by a doctor. Occasionally, brucellosis can recur despite treatment.

It is important to consult your doctor if symptoms persist or reoccur.

Preventative measures

You can minimise the risk of contracting brucellosis by:

• Not consuming undercooked meat or unpasteurised dairy products.
• Wearing protective equipment (such as gloves, eye goggles, aprons) when handling potentially infected animals, their fluids and/or their tissues (meat, offal).
• Avoiding feeding raw meat or offal from feral pigs to hunting dogs. More information is available for pig hunters, and owners of dogs who have been diagnosed with brucellosis.

Where to get help

• Your GP (doctor)
• Your veterinarian