Remaining Q Fever aware
18 Jul 2018
Q fever is an important zoonotic disease (i.e. a disease that can be passed from animals to humans or vice versa) for people who work with animals. Q fever can result in acute or chronic disease in humans and is caused by the bacterium Coxiella burnetii. Q Fever is a notifiable disease in all states and territories in Australia. That means doctors and nurses have to report patients diagnosed with the disease to their Chief Medical Officers within the states and territories’ departments of Health.
Many types of wild and domestic animals and their ticks 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 native animals such as kangaroos can be infected. It has even been isolated from fur seals. While the disease is carried in animals, clinical signs are rarely observed, and that’s what makes it dangerous for humans.
C. burnetii bacteria are highly infectious, and survive in air, soil, dust, and water sometimes for years. It can also be carried on items such as clothing, wool, hides, and straw. Placental tissue and fluids from infected animals contain high levels 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 of infected aerosols or dust, commonly when handling animals who are birthing.
Clinical symptoms of Q fever in humans vary from severe to ~50% of cases being asymptomatic. The interval between exposure to the bacteria and onset of illness ranges from 14 to 60 days, but is most commonly between 19-21 days. Acute symptoms of disease are often described as severe flu-like symptoms such as a high fever, muscle and joint pain, severe headache, and fatigue. Duration of illness usually lasts from 1-6 weeks, but in some cases can develop into chronic disease. Post-Q fever Fatigue Syndrome, Q fever endocarditis, and granulomatous lesions in bone, joints, lung, liver, testes and other soft tissues are all chronic diseases that can result from a Q fever infection.
Those most at risk are people who work with meat, livestock and animals, 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, resulting in higher levels of exposure to bacteria.
A vaccine is available to help protect people at risk against Q fever. Q fever immune status can be checked online on the Q Fever Register (www.qfever.org). Vaccination 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:
- Washing hands and arm thoroughly in soapy water after coming into contact with animals, carcasses or birthing materials.
- Minimising dust in yards and areas where animals are housed or slaughtered.
- Use protective outerwear, and remove it prior to coming into your home.
- Properly disposing of animal offal and afterbirth tissues.
If you suspect you, your staff or a family member has Q Fever, be sure to seek advice from your doctor, and be sure to mention you work with animals when getting checked out.