What is Q Fever

Q fever is a bacterial infection that is spread from animals to humans. Cattle, sheep, and goats are most commonly infected with Q fever bacteria, but these bacteria have been found in a variety of other animals and birds.

It is very rare for the infection to spread from person to person. Some people who get infected may not experience any symptoms.

Other people may have flu-like symptoms that last for a few weeks, or they may develop a more severe, long-lasting illness that can affect the heart, liver, lungs, bones, and brain (chronic Q fever).

What are the causes?

Q fever is caused by bacteria called Coxiella burnetii. These bacteria can spread to humans through milk, urine, feces, or birthing fluids of certain animals. The bacteria can also live in soil for months or even years. Dust from soil where animals have shed the bacteria can be picked up by the wind. Most infections in humans are caused by inhaling these particles into the lungs.

You can also get Q fever from:

• Eating or drinking unpasteurized milk or dairy products, such as cheese, from an infected animal.
• Having direct contact with an infected animal.

Tell your health care provider right away if you think you have had contact with affected animals or animal products.

What increases the risk?

The following factors may make you more likely to develop this condition:

• Living or traveling near farms or ranches.
• Working with livestock, such as cattle, sheep, or goats.
• Working in a stockyard or a meat-packing plant.
• Handling infected laundry.

You may have a higher risk for chronic Q fever infection if you:

• Have heart valve disease or an artificial heart valve.
• Have a weak disease-fighting (immune) system.
• Are pregnant.

What are the signs or symptoms?

Some people may have no signs or symptoms other than the presence of bacteria in the blood. If you do have symptoms, they develop suddenly 2–3 weeks after your exposure to the bacteria. They may be similar to symptoms of the flu or a severe cold. Signs and symptoms may include:

• High fever.
• Chills and sweats.
• Muscle aches.
• Severe headache.
• Nausea and vomiting.
• Diarrhea.
• Stomachache.
• Cough.
• Chest pain.
• Fatigue.

Pregnant women who develop Q fever may be at risk for giving birth early (preterm delivery), having a baby with a low birth weight, or losing the pregnancy (having a miscarriage).

After being treated for the infection, some people may continue to have certain symptoms (post-Q fever fatigue syndrome), such as:

• Headaches.
• Night sweats.
• Fatigue.

Some people may develop symptoms of chronic Q fever that start anytime from 6 weeks to several years after exposure to the bacteria. Most commonly, chronic infection affects the valves of the heart (endocarditis), but it can also affect the lungs (pneumonitis), liver (hepatitis), bones (osteomyelitis), brain (encephalitis), and the outer layer of the heart (pericarditis).

How is this diagnosed?

This condition may be diagnosed based on:

• Your symptoms.
• Your medical history.
• Your history of exposure to livestock.
• A physical exam.
• Blood tests, which may include:
  • Polymerase chain reaction (PCR) test. This test checks for DNA from Q fever bacteria.
  • Blood tests to check for proteins that were made by your immune system to fight the Q fever infection (antibodies).
• Removal of a small amount of infected tissue for testing (biopsy). This is rare.
• A test of heart function (echocardiogram).
• CT scan.
• Chest X-rays.
• Ultrasound.

How is this treated?

This condition is treated with antibiotic medicine. Treatment is most effective if it is started within 3 days of infection. Your health care provider may start treatment even before test results confirm the diagnosis.

If you have chronic Q fever, you may need to take antibiotics for a year or more. You may also need surgery to fix damage to your heart or other parts of your body.

Follow these instructions at home:

• Take over-the-counter and prescription medicines only as told by your health care provider.
• Take your antibiotic medicine as told by your health care provider. Do not stop taking the antibiotic even if you start to feel better.
• Keep all follow-up visits as told by your health care provider. This is important.

How is this prevented?

• Do not drink or eat unpasteurized dairy products.
• Avoid contact with animals, especially when they are giving birth.
• Take precautions when working or traveling around animals:
  • Make sure to wear breathing protection and eye protection, if necessary.
  • Wash your hands with soap and water after having any contact with animals or animal fluids, such as urine or birthing fluids.

Contact a health care provider if:

• Your symptoms do not get better with treatment.
• Your symptoms come back after treatment.
• You develop new symptoms.
• You are a woman who has had the infection, and you are pregnant or plan to become pregnant.

Get help right away if:

• You have chest pain.
• You have trouble breathing.

Summary

• Q fever is a bacterial infection that is spread from animals to humans.
• You can become infected by eating or drinking unpasteurized milk or dairy products from an infected animal, by inhaling infected bacterial particles in the air, or by having contact with an infected animal or its body fluids.
• Some people who get infected may not experience any symptoms. Other people may have flu-like symptoms that last for a few weeks, or they may develop a more severe, long-lasting illness that can affect the heart, liver, lungs, bones, and brain (chronic Q fever).
• This condition is treated with antibiotic medicine. Treatment is most effective if it is started during the first 3 days after infection occurs.
• Q fever is a serious infection that can cause intense symptoms and life-threatening complications. Tell your health care provider right away if you think you have had contact with affected animals or animal products.