Infectious diseasesepidemiology and surveillance

Page content: What is Q Fever? | Immunisation

What is Q Fever?

Q fever is an acute illness with fever, chills and muscle pains similar to severe influenza. Some people become infected without any illness being apparent, and a few develop a long-lasting illness with liver and heart complications. The micro-organism responsible, Coxiella burnetii, is carried by cattle, sheep and goats (particularly feral or wild goats) and is transmitted by contact with animal faeces, urine, blood and pregnancy fluids or by inhaling dust from infected premises.

Those most at risk of contracting the disease are abattoir workers and those closely associated with the meat industry (eg: contractors to abattoirs), sheep shearers and sometimes farmers. There is no endemic reservoir in Victoria, but the organism is commonly introduced in stock from interstate.

Immunisation

CSL Limited has prepared a vaccine, Q-Vax, which gives a very high level of protection, except if given after a person has already been infected. Q-Vax is different from other vaccines in that the recipient must first be tested for immunity, since those persons already immune may have severe reactions if given the vaccine.

The details of the immunisation program are as follows:

• Two visits are required, one week apart. At the first visit a skin test for Q fever is performed by injecting a small dose of diluted vaccine under the skin. At the same time 5-10 mls of blood is taken and tested for Q fever antibodies. Each employee is given a questionnaire enquiring about their duration of employment, past history of Q fever, allergies, etc. A previous history of infection with Q fever is a contraindication to vaccination.

• The skin test is read seven days later. Training is required in both the performance and reading / interpretation of the skin test. If both skin test and blood test are negative and the person is not allergic to eggs, and has not previously been vaccinated against Q fever, he/she is offered the vaccine, which is given by subcutaneous injection in the upper arm.

• Some reddening and tenderness is common after immunisation. Occasionally the vaccine may cause mild fever and muscle aches. Swelling is rare, as are more severe reactions like an abscess. Local abscess has occurred only in those who have had Q fever infection in the past, and pre-screening is designed to exclude this situation.

Preventing Q fever can lead to significant savings to the employer in avoiding WorkCover costs.

Contact details for trained Q fever immunisation providers is available by calling the Communicable Disease Control Unit on 1300 651 160.