Q Fever

Last updated: 16 January 2008

What is Q fever?

Q fever is a disease caused by a bacterium called Coxiella burnetii, spread to humans by infected animals. The bacteria are able to survive for long periods in the environment as they are resistant to heat, drying and many disinfectants.

What are the symptoms?

Symptoms of Q fever are similar to influenza and can sometimes be difficult to diagnose. Symptoms appear about 14-21 days after exposure and include:

• fever, which can last for 5-50 days or more
• chills, which last for 3-4 days
• sweats
• severe headache
• muscle pain
• painful joints
• fatigue
• nausea
• aversion to light
• weight loss

How is it spread?

• Cattle, sheep and goats are the main animals that are sources of this disease for humans. Other animals such as bandicoots, kangaroos, dogs and cats can also be infected with this disease.
• Infected animals shed the bacterium into their urine, faeces, milk, and birth by-products.
• The disease is transferred to humans by inhaling contaminated droplets or dust produced during slaughter or through the waste products (urine, faeces, milk, and birth by-products) of an infected animal.
• Transmission through ingestion of contaminated unpasteurised milk occurs rarely.

Who is at risk?

Q fever mainly affects:

• livestock workers
• meat industry workers
• veterinarians
• stockyard workers
• other agricultural workers, and
• other people who come into contact with animal secretions

People commencing work in these industries are at high risk of contracting the disease. Some workers in these industries, exposed over the years, have become immune to the disease without becoming sick.

How is it prevented?

• There is a vaccine available for Q fever. It is recommended for people who are entering into, or are working in, occupations that involve risk of exposure to the disease—such as abattoir workers, shearers or livestock farmers.
• Before vaccination, people must have skin and blood tests to determine if they have previously been infected with Q fever.
• Animal products of conception should be disinfected and disposed of appropriately. Access to potentially infected animals should be restricted.
• People who are not immune should not visit abattoirs

How is it diagnosed?

Diagnosis is based on consistent symptoms and signs. Blood tests determine antibody levels to Coxiella burnetii and are repeated at intervals to assess antibody response to the infection.

How is it treated?

Antibiotics are effective against Coxiella burnetii. The main antibiotic used to treat Q fever is doxycycline; however, there are other antibiotics that can be used if a person is allergic to tetracyclines.

What is the public health response?

• Laboratories must notify the local public health unit of any confirmed Q fever cases.
• Public health unit staff investigates each case to determine the likely source of infection, identify other people at risk of infection, ensure control measures are in place and provide information to cases.
• In occupational settings, non-immune workers should be vaccinated against Q fever.