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Tularemia (also known as deerfly fever or rabbit fever) is an infectious disease caused by the bacterium Francisella tularensis. This bacterium is found naturally in small mammals such as rabbits, rodents, and hares, as well as the bugs that feed on these animals. The bacterium can survive for weeks at low temperatures in water, moist soil, hay, straw, or decaying animal carcasses.

There are about 200 reported cases in the United States each year.


The most common ways you can get tularemia are by

  • Being bitten by flies, ticks, or other bugs carrying the disease
  • Handling infected animal tissue or fluids
  • Eating or drinking food or water contaminated by the bacteria
  • Breathing in the bacteria

You can also get tularemia by

  • Having direct contact with or ingesting bacteria-contaminated water, food, or soil
  • Handling contaminated animal skins
  • Inhaling infective aerosols from materials containing the bacteria


Tularemia infection varies from a mild illness to acute sepsis (serious infection of the blood or other tissues) and rapid death. After exposure to the bacteria, you will usually develop symptoms within 3 to 5 days, but they can take up to 21 days to appear. Symptoms include:

  • Sudden fever
  • Chills
  • Headaches
  • Diarrhea
  • Muscle aches
  • Joint stiffness or pain
  • Dry cough
  • Weakness

In most people, progressive weakness leads to a dry cough and pneumonia. Tularemia-induced pneumonia can cause chest pain, bloody sputum (saliva or mucus), and trouble breathing. Depending on how you were exposed to the bacteria, other symptoms may include

  • A red spot on the skin that enlarges to an ulcer
  • Ulcers in the mouth
  • Swollen and painful lymph glands
  • Swollen and painful eyes
  • Sore throat

The inhalation form of tularemia begins 3 to 5 days after you have been exposed to the bacteria. In some cases, pneumonia develops after several days or weeks. If left untreated, the disease could lead to respiratory failure.


Health care providers can diagnose tularemia by doing lab tests on your blood or sputum (saliva or mucus).


If you think you have symptoms of tularemia, contact your health care provider as soon as possible. Antibiotics, such as doxycycline or ciprofloxacin, can effectively treat tularemia. A tularemia vaccine strain is being reviewed by the Food and Drug Administration, but its future availability is uncertain, mainly because of the length of time it takes for the vaccine to work (about 2 weeks).

The U.S. Department of Defense also has developed an experimental tularemia vaccine. To date, health officials have limited the use of this vaccine to laboratory and other high-risk workers.



National Institute of Allergy and Infectious Diseases, USA.