Q fever

Q fever usually is a mild disease with flu-like symptoms. Many people have no symptoms at all. But 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 farmers, veterinarians and people who work with sheep in research labs.

The mild form of Q fever typically clears up within a few weeks with no treatment. But if Q fever recurs, you may need to take a combination of antibiotics for at least 18 months.

SYMPTOMS
Many people infected with Q fever never show symptoms. If you do have symptoms, you'll notice them about two to three weeks after exposure to the bacteria. Signs and symptoms may include:

High fever, up to 105 F (40.5 C)Severe headacheFatigue CoughNauseaDiarrhea

CAUSES
Q fever is caused by a type of bacteria called Coxiella burnetii, most commonly found in sheep, goats and cattle. It also can infect pets, such as 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:

Occupation. Certain occupations place you at higher risk because you're exposed to animals and animal products as part of your job. At-risk occupations include veterinary medicine, meat processing, livestock farming and animal research.Location. Simply being near a farm or farming facility may put you at higher risk of Q fever, because the bacteria can travel long distances,

accompanying dust particles in the air.Your sex. Men are more likely to develop symptomatic acute Q fever.

Risks for chronic Q fever

The risk of eventually developing the more deadly form of Q fever is increased in people who have:

Heart valve diseaseBlood vessel abnormalitiesWeakened immune systems

COMPLICATIONS
A Q fever recurrence can affect your heart, liver, lungs and brain, giving rise to serious complications, such as:

Endocarditis. An inflammation of the membrane surrounding your heart, endocarditis can severely damage your heart valves. Endocarditis is the most common and the most deadly of Q fever's complications.Lung issues. Some people who have Q fever develop pneumonia. This can lead to acute respiratory distress, a medical emergency in which you're not getting enough oxygen.Pregnancy problems. Chronic Q fever increases the risk of miscarriage, low birth weight, premature birth and stillbirth.Liver damage. Some people who have Q fever develop hepatitis, an inflammation of the liver that interferes with its function.Meningitis. Q fever also can cause meningitis, an inflammation of the membrane surrounding your brain and spinal cord.

DIAGNOSIS
To diagnose Q fever, your doctor will perform one or more blood tests, along with additional tests if chronic Q fever is suspected.

Lab tests

Your doctor may want to check your blood for antibodies to the Coxiella burnetii antigen and for evidence of liver damage.

Imaging tests

Chest X-ray. Q fever can cause pneumonia in some people. A chest X-ray can be used to see if your lungs look healthy.Echocardiography. If chronic Q fever is suspected, your doctor may do an echocardiogram to check for problems with your heart valves.

TREATMENT
Treatment for Q fever depends on the severity of your symptoms. Mild or nonsymptomatic cases of acute Q fever often get better in about two weeks with no treatment.

Medications

If you have more severe symptoms, your doctor will prescribe antibiotics. 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.

Surgery

If you have Q fever endocarditis, you may need surgery to replace damaged heart valves.