By Rachel Gordon, Livestock Biosecurity Network regional manager
With lambing currently underway, and calving due to start imminently, it is a good time to give some thought to Q fever, and whether you are at risk.
This zoonotic disease (meaning a disease that can be passed from animals to humans) was originally recognised in Australia in the 1930s. The term ‘Q fever’ is a shortened version of ‘Query fever’, because the cause was unknown. We now know that Q fever is caused by the bacterium Coxiella burnetii, and exists worldwide.
Many types of animals can be infected with C. burnetii. Sheep, goats, and cattle are the main sources of infection for humans, but other animals including cats, dogs and kangaroos can be infected. It has even been isolated from fur seals.
The C. burnetii bacteria is highly infectious, and survives in air, soil, dust, and water. It can also be carried on items such as clothing, wool, hides, and straw. Placental tissue and fluids from infected animals contain high numbers of C. burnetii, and this is one of the ways it enters the environment. It is also shed in milk, urine, and faeces. Humans usually contract Q fever through inhalation, either infected aerosols or dust, or by being near infected animals as they give birth.
Clinical symptoms of Q fever in humans vary, but in Australia these symptoms include a high fever, muscle and joint pain, severe headache, and fatigue. These symptoms are similar to other infections such as influenza, and as such Q fever can often be misdiagnosed.
The severity of the illness also varies, from showing little to no symptoms at all right through to requiring several weeks’ rest. It is also possible to develop chronic Q fever. There is also a condition known as Post-Q fever Fatigue Syndrome, which has been known to develop in people who have suffered an acute case of Q fever.
Those most at risk are people who work with meat and livestock, including abattoir workers, shearers, producers and vets. There reportedly are also cases of people contracting the disease through simply being in the vicinity of places such as saleyards, farms, and feedlots and other areas where livestock congregate, and being exposed to the bacteria.
There is a vaccine available in Australia to help protect people at risk against Q fever. It is a three-step process, involving a blood test, a skin test and, depending upon the results of these tests, the vaccination itself. The blood and skin tests must be performed on the same day and determine if a person has been previously exposed to Q fever. These tests are necessary, as a person who has already had Q fever can develop severe side effects if they are vaccinated.
Those that are vaccinated may develop minor side effects include a sore arm, headache, fever, and a general feeling of being unwell.
The Q fever vaccine is currently not recommended for children under the age of 15. Be aware of the risk Q fever poses to unvaccinated children if they are with you while you are assisting with a difficult lambing or calving.
As well as utilising the available vaccine, people can reduce the risk of Q fever through:
Q fever is a serious zoonotic disease. All of us who work with or around livestock need to be aware of Q fever, and take the necessary steps to protect ourselves.
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