Q fever is a disease caused by infection with bacteria called "Coxiella burnetii" which affects both humans and animals. This organism is uncommon but may be found in cattle, sheep, goats and other domestic mammals, including cats and dogs. The infection results from inhalation of contaminated particles in the air, and from physical contact with the vaginal mucus, milk, feces, urine or semen of infected animals.

Some of the occupations at increased risk for Q fever include the following:

• Certain groups of medical and health care personnel
• Farmers, ranchers, and farm workers in contact with cattle, sheep, and goats,
  Hunters and trappers,
• Laboratory animal researchers and support staff
• Meat packers, rendering plant workers, hide and wool handlers
• Pet shop workers
• Stockyard workers
• Truck drivers and visitors to animal auctions
• Workers who care for pets and livestock--veterinary personnel
• Zoo attendants

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.

Causes

• Cattle, sheep, and goats are the primary reservoirs of C. burnetii. 
• Infection has been noted in a wide variety of other animals, including other species of livestock and in domesticated pets. 
• Infected animals also release the microbe in milk and manure.
• Q fever can be spread by drinking infected milk
• Person to person transmission (rare cases)

Signs & Symptoms
Many infections are asymptomatic. People can have Q fever without knowing it or mistake it for mild flu. Often, it is impossible to tell without laboratory tests. Common symptoms resemble a serious case of the

• Abdominal pain
• Chest pain
• Chills and sweating
• Confusion
• Diarrhea
• Flu with high fever (up to 104-105° F)
• General feeling of sickness and loss of appetite
• General malaise
• Liver and heart disease
• Myalgia
• Nausea
• Severe headache
• Sore throat
• Vomiting

Some patients develop a slight, dry cough because of a lung inflammation known as pneumonitis. Most symptoms disappear after 7-10 days. However, afflicted people can feel generally ill with loss of appetite for several weeks.

Diagnosis
Because the signs and symptoms of Q fever are not specific to this disease, it is difficult to make an accurate diagnosis without appropriate laboratory testing.

• Laboratory tests for Q fever measure antibodies that circulate in the blood.
• Antibodies are protective substances that the body produces in defense against infectious diseases.
• Q fever can be diagnosed in patients who develop these antibodies in their blood following a period of unexplained feverish illness.

Preventions
For most effective prevention, the Q fever should be eliminated from animals. The risk of infection from the workplace can be reduced by:

• Personal precautions
• Vaccination of workers
• Workplace hygiene.

The following measures should be used in the prevention and control of Q fever:

• Animals should be routinely tested for antibodies.
• Appropriately dispose of fetal membranes and aborted fetuses at facilities housing sheep and goats.
• Counsel persons with pre-existing cardiac vascular disease
• Educate the public on sources of infection.
• Holding facilities for sheep should be located away from populated areas. 
• Use appropriate procedures for bagging, autoclaving, and washing of laboratory clothing.
• Use only pasteurized milk and milk products.
• Vaccinate individuals engaged in research with pregnant sheep or live C. burnetii.

Treatments
The antibiotic tetracycline is often used to treat Q fever. Patients usually recover promptly when treatment is started without delay.

• Antibiotic treatment is most effective when initiated within the first 3 days of illness.
• Quinolone antibiotics have demonstrated good in vitro activity against C. burnetii and may be considered by the physician.
• Therapy should be started again if the disease relapses.
• Surgery to remove damaged valves may be required for some cases of C. burnetii endocarditis.
• Q fever in pregnancy is especially difficult to treat because doxycycline and ciprofloxacin are contraindicated in pregnancy. The preferred treatment is five weeks of co-trimoxazole.