What Is Q Fever?

Medically Reviewed by Poonam Sachdev on November 10, 2021
Written by Jeffrey Weishaupt
3 min read

Q fever is an infection transmitted to humans by animals.

It usually causes mild flu-like symptoms, which typically appear after two to three weeks after contracting the disease. Generally, the bacterium makes about five out of 10 people sick.

Q fever can also become deadly and may damage your vital organs like lungs, heart, and liver.

The primary cause of Q fever is the inhalation or ingestion of the bacterium Coxiella burnetii. The bacterium is mainly found in cattle, including sheep, goats, and lambs. Q fever transmission occurs in both humans and pets.

People working in specific fields, such as farming, veterinary medicine, and animal studies, are at a higher risk for Q fever.

The primary causes for Q fever transmission include exposure to animal fluids like:

When these products dry, the bacteria Coxiella burnetii becomes a part of the barnyard dust. It then floats in the air and infects humans.

Less common modes of Q fever transmission are:

  • Working in a slaughterhouse
  • Drinking unpasteurized milk
  • Hunting
  • Dressing infected animals

Many people with Q fever don't show symptoms, while others notice them between three to 30 days after infection.

Some common Q fevers symptoms include:

  • High fever (up to 105 degrees Fahrenheit or 41 degrees Celsius)
  • Chills or sweats
  • Cough
  • Frequent headache
  • Nausea or vomiting
  • Diarrhea
  • Chest pain
  • Stomach pain
  • Muscle pains
  • Significant weight loss
  • Fatigue or drowsiness

These symptoms can be mild or severe. If you observe severe symptoms, you have a higher risk of getting more serious illnesses such as pneumonia or hepatitis.

Chronic Q fever affects a tiny percentage of people — less than five out of 100. This type of Q fever develops months or years after the first diagnosis. Chronic Q fever is dangerous for your heart, lungs, liver, and brain. 

In some conditions, it can even lead to death.

Some complications caused due to chronic Q fever include:

  • Endocarditis. It is one of the most deadly complications of Q fever. The condition inflames the inner membrane of your heart and damages its valves.
  • Meningitis. Q fever can also inflame the membrane surrounding your brain and spinal cord. The condition is called meningitis.
  • Lung issues. People with Q fever are vulnerable to pneumonia. It causes a shortage of oxygen to your lungs, also known as acute respiratory distress.
  • Pregnancy problems. Chronic Q fever is very dangerous for pregnant women. It increases the risk of miscarriage, premature birth, stillbirth, and low weight birth of the baby.
  • Liver damage. Chronic Q fever can lead to the inflammation of the liver, known as hepatitis.

If not treated, chronic Q fever can be deadly.

The standard Q fever treatment is the antibiotic doxycycline (Vibramycin). The duration of the treatment depends on the type of Q fever you have. For mild Q fever, the antibiotic treatment goes for two to three weeks, though this type of Q fever often gets better with no treatment. 

In the case of chronic Q fever, the treatment duration can extend to 18 months or more. People with chronic Q fever have to take a combination of antibiotics. 

Even after the chronic Q fever treatment, your doctor will ask you to visit for follow-up tests. These visits continue for years in case the infection recurs.

If antibiotics don't work, the doctor prescribes anti-inflammatory drugs to people with Q fever. The commonly-used medicine is hydroxychloroquine (Plaquenil).

If the Q fever causes endocarditis, you may have to undergo surgery to replace damaged heart valves.

The U.S Food & Drug Administration (FDA) has not approved any vaccine for Q fever. But, Australia licensed a vaccine against Q fever in 1989.

You can prevent Q fever by:

  • Avoiding the use of raw milk and related products. Instead, use only pasteurized milk and pasteurized milk products. Pasteurization kills all sorts of bacteria.
  • Limiting your contact with animals, especially cattle. 
  • Avoiding animals' birthing places.