Q fever is a bacterial infection that can be spread to humans by infected animals – most commonly by sheep, cattle and goats.
The infection is found worldwide, but cases in humans are rare in the UK. Around 50 cases of Q fever are reported in the UK each year.
Most people with Q fever will either have no symptoms, or will only have mild flu-like symptoms that pass within two weeks.
However, the symptoms can sometimes last several months, and occasionally the infection can lead to life-threatening problems if it spreads to other parts of the body, such as the heart.
If you get Q fever while pregnant, your baby may be born early or have a low birthweight, and there is a risk of having a miscarriage orstillbirth.
How Q fever is spread
Q fever is caused by Coxiella burnetii (C. burnetii) bacteria, which are usually spread to animals by infected ticks. The animals that pose the biggest risk to humans are:
- domesticated pets – such as dogs, cats and rabbits
The bacteria can be found in an infected animal's milk, blood, urine, poo, and birth by-products – such as the afterbirth (placenta). Birth products pose the greatest risk, because they can contain a high number of bacteria.
The bacteria can be spread to humans by:
- breathing in particles released by infected animals – particularly when animals are being slaughtered or giving birth
- breathing in particles of contaminated soil, dust, hay or straw bedding
- infected particles coming into contact with your eyes or a cut in your skin
- drinking unpasteurised milk from an infected animal
- being bitten by an infected tick – although this is very rare and there have not been any recorded cases of this in the UK
It's also possible, although incredibly rare, for Q fever to spread between people through sexual intercourse or by a pregnant woman passing the infection to her unborn child.
Who's most at risk?
People who work closely with livestock are most at risk, such as:
- abattoir workers
- meat packers
You're also more vulnerable to the infection, and more likely to experience complications, if you have a history of heart valve disease, a weakened immune system (for example, because of chemotherapy), or you're pregnant.
Signs and symptoms
Q fever doesn't always cause symptoms. If you do develop symptoms, this is usually within two to three weeks of infection.
The main symptoms of Q fever include:
- a high temperature (fever)
- severe headaches
- muscle and joint pain
- a sore throat
- sensitivity to light (photophobia)
- weight loss
In some cases, the infection can also cause problems such aspneumonia. Symptoms can include a dry cough and a sharp chest painmade worse by breathing deeply, coughing or laughing.
These problems usually pass within two weeks and most people will make a full recovery.
Occasionally, however, symptoms of Q fever last six months or more. This is known as chronic Q fever, and it can cause you to feel tired and generally unwell for a long time. In rare cases, it can lead to a serious problem where the inner lining of the heart becomes inflamed (endocarditis).
When to seek medical advice
You should see your GP if you develop severe or persistent symptoms of Q fever, or you're pregnant and are worried you may have been exposed to the infection.
Your GP may suspect Q fever if you have recently been in close contact with potentially infected material, such as animal birth products, and the diagnosis can usually be confirmed with a blood test.
Treating Q fever
Q fever usually lasts for about two weeks and often gets better without treatment, although you may need to take antibiotics for 7-14 days if your symptoms are severe or don't improve.
If you are prescribed antibiotics, it's important that you finish the whole course, even if you feel better.
Long-term Q fever is usually much more difficult to treat, and treatment normally involves taking a combination of antibiotics for at least 18 months.
If you develop any serious complications, such as endocarditis, you may need to be treated in hospital.
Preventing Q fever
A vaccine for Q fever isn’t available in the UK, so the best way to avoid the infection is to reduce your exposure to potentially infected material.
If you work with animals, you should:
- wash your hands thoroughly and regularly
- clean new wounds immediately and cover any existing wounds
- wear appropriate protective clothing, such as waterproof gloves and goggles
- avoid eating in potentially contaminated areas
- ensure all animal birth products are disposed of properly
You can also reduce your risk of getting Q fever by avoiding unpasteurised milk and dairy products, and by not touching anything that may have been in contact with animal blood, poo or urine.
Pregnant women should avoid contact with sheep and lambs during lambing season (January to April) in particular, and should avoid handling clothing, boots and other items that have come into contact with ewes or lambs.
- Why should pregnant women avoid sheep during the lambing season?
- What infections can animals pass to people?
- How can I avoid catching an infection from an animal?