Q fever - including symptoms, treatment and prevention

Q fever is an infection caused by bacterium Coxiella burnetii. 

It is spread to humans commonly from cattle, sheep and goats, as well as domestic animals and kangaroos.

Infection in animals is probably common, but infected animals often have no signs or symptoms.

Q fever is a notifiable condition¹

How can you get Q fever

Q fever is an occupational disease of meat workers, farmers and veterinarians (vets).

• Infection of humans usually occurs by inhalation of the bacteria in air carrying dust contaminated by dried placental material, birth fluids, urine or faeces of infected herd animals.
• Contaminated clothing, wool, hides or straw may also be a source of infection.
• While herding, shearing or transporting animals.
• While mowing grass contaminated by infected animal excretions.
• When visiting, living or working in/near a high-risk industry.
  
• People living downwind of an abattoir or livestock farm. 
• Direct contact with infected animal tissue or fluids on broken skin (e.g. cuts or needlestick injuries when working with infected animals).
• Drinking unpasteurised milk from infected cows, sheep and goats.
• Q fever organisms are resistant to heat, drying and many common disinfectants, allowing them to survive for long periods in the environment.
  
• Person-to-person spread is extremely unlikely.  

Signs and symptoms

Only about half of all people infected with Coxiella burnetii show signs of clinical illness. However, the onset of symptoms is usually sudden, with one or more of the following:

• fever, which may last up to 4 weeks
• severe headache
• sweats and chills
• fatigue – and prolonged fatigue (post Q fever fatigue syndrome) may follow infection
• muscle aches
• confusion
• sore throat
• dry cough
• chest pain on breathing
• nausea, vomiting
• diarrhoea
• abdominal pain.

Q fever has been reported to cause pneumonia (lung infection or inflammation) and hepatitis (inflammation of the liver). However, most people will recover within several months without any treatment and only 1 to 2% of people with acute Q fever die of the disease.

Some people may develop chronic Q fever after exposure. Infection persists for more than 6 months and may not be apparent until many years after the initial infection. While rare, it can have serious complications such as endocarditis (infection of the heart valves).

People most at risk of developing chronic Q fever include:

• those with underlying heart abnormalities
• transplant recipients
• cancer patients
• those with chronic kidney disease.

Diagnosis

Diagnosis is made by a series of blood tests.

Laboratories must notify the local public health unit of any confirmed Q fever cases.

Employers must notify SafeWork SA about Q fever infections in workers that may have been acquired in their workplace.

Incubation period

(time between becoming infected and developing symptoms)

Usually 2 to 3 weeks, range 4 days to 6 weeks.

Infectious period

(time during which an infected person can infect others)

Person-to-person spread occurs rarely.

Treatment 

Effective antibiotic therapy and appropriate monitoring and follow up.

Prevention

For those who are not immune (through vaccination or past infection), the following measures can reduce the risk of infection:

• wash hands and arms thoroughly in soapy water after any contact with animals
• wear a properly fitted P2 mask (available from pharmacies and hardware stores) and gloves and cover wounds with waterproof dressings when handling or disposing of animal products, waste, placentas, and aborted foetuses. This should not be considered a substitute for Q fever vaccination
• wear a properly fitted P2 mask when working with dust containing animal products
• wash animal urine, faeces, blood and other body fluids from equipment and surfaces where possible
• remove and wash dirty clothing, coveralls and boots worn during high-risk activities on site
• avoid taking these items home to reduce the risk of infection to your household. If you do take them home, bag and wash them separately (should only be handled by those immune to Q fever)
  
• exclusion from childcare, preschool, school or work is not necessary
• do not drink unpasteurised milk.

Immunisation

People working in high-risk occupational groups are strongly recommended to be vaccinated against Q fever which provides a high level of protection. 

Q fever vaccination is recommended for:

• abattoir workers and contract workers in cattle, sheep dairy and goat abattoirs (but not pig abattoirs)
• farmers, stockyard workers and livestock transporters
• agricultural college staff and students and wildlife and zoo workers exposed to high-risk animals
• shearers and wool sorters
• veterinarians, veterinary nurses and students
• professional dog and cat breeders, tanning and hide workers and laboratory personnel handling veterinary products or working with the organism
• others exposed to cattle, camels, sheep, goats and kangaroos or their products.

People considering immunisation against Q fever should contact their doctor.

Prior to immunisation, a blood and a skin test is recommended to see if the individual has previously been exposed to Q fever – either naturally or by previous vaccination.

Vaccinating those already exposed to Q fever can result in severe reactions.

Vaccination will not prevent disease in someone who has already been infected but is in the incubation period of the disease.

For further information see the Q fever vaccination providers in South Australia list (PDF 82 KB)

1 – In South Australia the law requires doctors and laboratories to report some infections or diseases to SA Health. These infections or diseases are commonly referred to as 'notifiable conditions'.