Q feverDefinition: Q fever is a bacterial infection that can affect the lungs, liver, heart, and other parts of the body.
Alternative Names: Query fever
Causes, incidence, and risk factors: Q fever is found around the world and is caused by the bacteria Coxiella burnetii. The bacteria affects sheep, goats, cattle, dogs, cats, birds, rodents, and ticks , as well as some other animals. Infected animals shed this bacteria in:
- Birth products
- Feces
- Milk
- Urine
Humans usually get Q fever by breathing in contaminated droplets released by infected animals. Drinking raw milk has also caused infection in rare cases. People at highest risk for this infection are:
- Farmers
- Laboratory workers who work with Coxiella burnetii
- Sheep and dairy workers
- Veterinarians
Chronic Q fever develops in people who have been infected for more than 6 months.
People at highest risk include those with heart valve problems or weakened immune systems.
Symptoms: It usually takes about 20 days after exposure to the bacteria for symptoms to occur. Most cases are mild, yet some severe cases have been reported.
Symptoms of acute Q fever may include:
- Chest pain with breathing
- Clay-colored stools
- Cough
- Fever
- Headache
-
Jaundice
- Muscle pains
- Rash (not common)
- Shortness of breath
Symptoms of chronic Q fever may include:
- Chills
- Fatigue
- Night sweats
- Prolonged fever
- Shortness of breath
Signs and tests: The health care provider will suspect Q fever in people who have been exposed to the Coxiella burnetii bacteria who develop:
- Endocarditis
- Flu-like symptoms
- Hepatitis
- Pneumonia
Q fever is diagnosed with a blood antibody test (serology ).
Treatment: The main treatment for Q fever is with antibiotics. For early-stage (acute) Q fever, doxycycline is the recommended antibiotic.
For chronic Q fever, a combination of doxycycline and hydroxychloroquine is often used. You may need to take antibiotics for several months.
Expectations (prognosis): The outlook for people who get treated in the early stages of Q fever is generally good.
Chronic Q fever requires long-term treatment with antibiotics. Your health care provider should check you often to make sure the disease has not returned.
Calling your health care provider: Notify your medical provider if you have symptoms of Q fever, especially if you believe you have been exposed to the bacteria. Although many different illnesses can cause similar symptoms, you may need to be evaluated for Q fever.
Prevention: People at risk (for example, farmers and veterinarians) should always:
- Carefully dispose of animal products that may be infected
- Disinfect any contaminated areas
- Thoroughly wash your hands
Pasteurizing milk can also help prevent Q fever.
Prompt treatment can prevent early Q fever from becoming chronic.
References: Marrie TJ, Raoult D. Coxiella burnetii (Q fever). In: Mandell GL, Bennett JE, Dolin R, eds. Principles and Practice of Infectious Diseases. 7th ed. Philadelphia, Pa: Elsevier Churchill Livingstone; 2009:chap 189.
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