Q fever very rarely causes any signs of clinical disease. Rarely the Q fever organism will cause abortion in cows, sheep and goats. This disease is significant because it can cause serious illness in people.
Cause – a bacterial infection (Coxiella burnetii)
Infected animals shed the organism in urine, milk, faeces and placental fluids. Contact with foetuses and foetal membranes from aborted animals can expose individuals to high doses of infective material. The Q fever organism is very tough and can survive for months in the environment.
Animals likely to be affected
Cattle can be infected at any age and can remain infected for months or years.
Other diseases with similar signs
Other causes of abortion in cattle.
Confirming the diagnosis
Blood tests can determine if animals have been infected with the Q fever organism. Other laboratory tests are usually required to sort out the cause of abortion in cattle.
Spread of the disease
Animals are infected with the Q fever organism by inhaling or ingesting infected material such as urine, milk, faeces or after-birth from infected animals. People are infected most frequently by inhaling infected material from these same sources or from environmental contamination. Wind borne transmission of the organism in dust is an important source of infection.
Risks to people
It is very easy for people to catch Q fever. It can cause a prolonged fever and headaches and some people develop serious symptoms involving the lungs, liver, heart or brain. About 10% people that are seriously ill with Q fever do not return to normal within 12 months. People who have close contact with farm animals such as farm workers, vets, abattoir staff and livestock agents carry the greatest risk of contracting Q fever. Abattoir workers are at risk of infection when working on pregnant animals. Farmers need to use care when assisting at calvings and avoid direct contact with afterbirth materials. Aborted foetuses and afterbirth should be disposed of safely by burning.
Animals with Q fever are not treated, but if people become infected it is important that they receive prompt medical attention to relieve symptoms and avoid serious complications.
A vaccine is available for people who are in close contact with farm animals and it is recommended that all dairy farmers and their staff are vaccinated.
Some useful websites with Q Fever information include: