The ‘Q’ in Q fever stands for ‘query’. This is because when this bacterial infection was first indentified, its cause was unknown. The cause is now understood but the name has remained the same. Q fever is spread to humans through animals – usually goats, sheep and cattle. In rare cases it can be spread from human to human, usually through sexual intercourse. It is caused by the coxiella burnetii bacteria and is most common in Australia and the south of France. Those who are most at risk of contracting the disease are farmers, meat packers, stablehands, vets and abattoire workers.
What causes it?
Q fever is caused by the coxiella burnetii bacteria. This is usually spread to animals through infected ticks and most commonly affect farm animals and household pets. The animals themselves often do not experience any symptoms, so it can be hard to identify whether or not they are infected, although it can increase the likelihood of miscarriage in cows and sheep.
The bacteria can be released by an infected animal through its:
- birth by-products, such as the placenta, which is sometimes known as the afterbirth.
It can be spread both by direct and indirect contact. Infection through direct contact, which is most common, happens when a person breathes in the bacteria, which can also survive up to 10 months and people can become infected through the spread of contaminated soil, dust or hay. It is thought to be very unlikely to catch the fever from a person who has it, unless it is through sexual intercourse or a pregnant woman passing it on to her unborn child.
What are the symptoms?
There are two types of Q fever. Acute is the most common and least serious. Some people develop chronic Q fever, which is more serious. It is not known exactly why some people develop it and not others, but affected infividuals usually have a pre-existing health condition, which makes them vulnerable to infection.
Acute Q fever symptoms include:
- high temperature (fever) of 394°C (104°F) or above
- severe headache
- muscle and joint pain
- sensitivity to light
- weight loss
- a skin rash (less common)
How is it treated?
The symptoms of acute Q fever usually get better within 2 weeks of developing. A course of antibiotics is often recommended to shorten the time of infection. Chronic Q fever can be more difficult to treat as the particular bacteria which causes the condition can sometimes be resistant to antibiotics. So, a course of a combination of pills over an 18-month period is recommended.