Q Fever

Q fever is a zoonotic disease caused by Coxiella burnetii, a species of bacteria that is distributed globally.  In 1999, Q fever became a notifiable disease in the United States but reporting is not required in many other countries. Because the disease is underreported, scientists cannot reliably assess how many cases of Q fever have actually occurred worldwide.  Many human infections are inapparent.

Symptoms of Q fever

Only about one-half of all people infected with Coxiella burnetii show signs of clinical illness. Most acute cases of Q fever begin with sudden onset of one or more of the following: 

• high fevers (up to 104-105° F)
• severe headache
• general malaise
• myalgia
• confusion
• sore throat
• chills
• sweats
• non-productive cough 
• nausea
• vomiting
• diarrhea
• abdominal pain
• chest pain. 

Fever usually lasts for 1 to 2 weeks. Weight loss can occur and persist for some time. Thirty to fifty percent of patients with a symptomatic infection will develop pneumonia. Additionally, a majority of patients have abnormal results on liver function tests and some will develop hepatitis. In general, most patients will recover to good health within several months without any treatment. Only 1%-2% of people with acute Q fever die of the disease.

Chronic Q fever, characterized by infection that persists for more than 6 months is uncommon but is a much more serious disease. Patients who have had acute Q fever may develop the chronic form as soon as 1 year or as long as 20 years after initial infection. A serious complication of chronic Q fever is endocarditis, generally involving the aortic heart valves, less commonly the mitral valve. Most patients who develop chronic Q fever have pre-existing valvular heart disease or have a history of vascular graft. Transplant recipients, patients with cancer, and those with chronic kidney disease are also at risk of developing chronic Q fever. As many as 65% of persons with chronic Q fever may die of the disease. 

The incubation period for Q fever varies depending on the number of organisms that initially infect the patient. Infection with greater numbers of organisms will result in shorter incubation periods. Most patients become ill within 2-3 weeks after exposure. Those who recover fully from infection may possess lifelong immunity against re-infection.

You're at a higher risk of if you work around animals — such as at a slaughterhouse, meat packing plant or a veterinary office — or if you live on a farm or ranch. Your doctor will likely prescribe antibiotics for you or your child for Q fever.

Q Fever Symptoms to Q