Q fever is a bacterial infection caused by Coxiella burnetii, which is transmitted to humans through inhaling dust contaminated by the bacteria. This dust is released in the feces, urine, or placenta of infected animals, such as cows, goats, and sheep. The disease is more common in people who have close contact with these animals, including veterinarians, farmers, and laboratory staff.
While Q fever is often asymptomatic, it can cause flu-like symptoms in some individuals, including cough, severe headache, fever, and muscle aches. In more severe cases, the infection can lead to complications such as endocarditis, hepatitis, and extensive lung disease.
In most cases, the infection resolves on its own without treatment. However, doctors may prescribe antibiotics, such as doxycycline, ciprofloxacin, or rifampin, to reduce symptom duration and prevent the disease from becoming chronic.
Main symptoms
Symptoms of Q fever include:
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Headache
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Fever above 104°F (40°C)
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Muscle aches
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Pneumonia
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Nausea
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Diarrhea
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Vomiting
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Extreme fatigue
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Skin irritation (in some cases)
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Liver disease
While Q fever is often asymptomatic, symptoms can develop suddenly and last for a few days, or persist for six months or more in some cases. The disease may cause long-term effects on the heart, liver, lungs, and nervous system.
Since Q fever shares symptoms with other conditions, such as viral pneumonia, brucellosis, and tuberculosis, healthcare providers will need to conduct laboratory tests to differentiate Q fever from other diseases and determine the right treatment.
Confirming a diagnosis
A healthcare provider, usually an infectious disease specialist or internist, will diagnose Q fever based on the patient’s medical history, occupation, and potential exposure to cows, goats, and/or sheep. Blood tests, including PCR and liver function tests, as well as chest X-rays, are often used to identify lung abnormalities that may be caused by the infection.
In some cases, doctors may recommend a transthoracic echocardiogram to check for potential damage to the heart valves due to Coxiella burnetii infection, which could lead to endocarditis.
What causes Q fever?
Q fever is caused by the bacteria Coxiella burnetii, which is found in cows, goats, and sheep. People can become infected by inhaling particles from contaminated feces, urine, or placenta. Although less common, pets like dogs, cats, and rabbits can also carry the bacteria.
While it’s believed that consuming raw meat and dairy products from infected animals, or receiving a blood transfusion from an infected donor, could potentially transmit the disease, these transmission routes have not been definitively confirmed.
Treatment options
The primary goal of Q fever treatment is to prevent chronic disease and complications. Doctors often prescribe antibiotics like doxycycline to help reduce symptoms and prevent long-term effects. If endocarditis develops, a combination of doxycycline, ciprofloxacin, and rifampin may be used, with treatment duration depending on the severity of symptoms and the amount of bacteria present.
Pregnant women who contract Q fever may be treated with trimethoprim-sulfamethoxazole throughout their pregnancy to reduce the risk of complications.
Possible complications
One of the main long-term effects of Q fever is the development of endocarditis, which may be accompanied by glomerulonephritis, osteomyelitis, or central nervous system issues, especially in individuals with a history of heart valve disease. In pregnant women, Q fever can result in spontaneous abortion, fetal growth restriction, low amniotic fluid, premature labor, or even fetal death.