Q fever is an infection caused by the bacterium Coxiella burnetii. Q fever is usually a mild disease with flu-like symptoms. Many people have no symptoms at all. In a small percentage of people, the infection can resurface years later. This more deadly form of Q fever can damage your heart, liver, brain and lungs.
Q fever is transmitted to humans by animals, most commonly sheep, goats and cattle. When you inhale barnyard dust particles contaminated by infected animals, you may become infected. High-risk occupations include farming, veterinary medicine and animal research.
Mild cases of Q fever clear up quickly with antibiotic treatment. But if Q fever recurs, you may need to take antibiotics for at least 18 months.
Many people infected with Q fever never show symptoms. If you do have symptoms, you'll probably notice them between three and 30 days after exposure to the bacteria. Signs and symptoms may include:
Q fever is caused by the bacterium Coxiella burnetii, commonly found in sheep, goats and cattle. The bacterium can also infect pets, including cats, dogs and rabbits.
These animals transmit the bacteria through their urine, feces, milk and birthing products — such as the placenta and amniotic fluid. When these substances dry, the bacteria in them become part of the barnyard dust that floats in the air. The infection is usually transmitted to humans through their lungs, when they inhale contaminated barnyard dust.
Certain factors can increase your risk of being infected with Q fever bacteria, including:
The risk of eventually developing the more deadly form of Q fever is increased in people who have:
A Q fever recurrence can affect your heart, liver, lungs and brain, giving rise to serious complications, such as:
A Q fever vaccine has been developed in Australia for people who have high-risk occupations, but it's not available in the U.S.
Whether you're at high risk of Q fever or not, it's important to use only pasteurized milk and pasteurized milk products. Pasteurization is a process that kills bacteria.
To diagnose Q fever, your doctor will perform one or more blood tests, along with additional tests if chronic Q fever is suspected.
Your doctor may want to check your blood for antibodies to the Coxiella burnetii antigen and for evidence of liver damage.
Q fever is treated with the antibiotic doxycycline. How long you take the medicine depends on whether or not you have acute or chronic Q fever. For acute infections, antibiotic treatment lasts two to three weeks.
People who have chronic Q fever usually must take a combination of antibiotics for at least 18 months. Even after successful chronic Q fever treatment, you'll need to go back for follow-up tests for years in case the infection returns.
Mild or nonsymptomatic cases of acute Q fever often get better with no treatment. However, if you have symptoms of Q fever or if you're pregnant, antibiotic treatment is recommended. Your treatment plan may vary if you're unable to take doxycycline.
If you have Q fever endocarditis, you may need surgery to replace damaged heart valves.
You might first visit your primary care doctor because of your symptoms. He or she might refer you to an infectious disease specialist.
Here's some information to help you get ready for your appointment, and what you might expect from your doctor.
Preparing a list of questions can help you make the most of your appointment time. For Q fever, some basic questions to ask your doctor include:
In addition to the questions that you've prepared to ask your doctor, don't hesitate to ask questions during your appointment at any time that you don't understand something.
Your doctor is likely to ask you a number of questions. Being ready to answer them may reserve time to go over any points you want to spend more time on. Your doctor may ask:
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