Tularemia, also known as "rabbit fever," is an illness caused by the bacterium Francisella tularensis.
It is spread through contact with animals that have the bacteria—usually through contact with wild animals, including hares, rabbits, squirrels, muskrats, beavers, and deer. However, certain domestic animals can sometimes have tularemia (sheep and cats).
When there are outbreaks of tularemia, rabbits are most often involved. The bacteria can also be found in ticks and deerflies and can be spread to humans through an infected bite.
Tularemia in humans is rare in Wisconsin, averaging fewer than one case per year since 1980. Hunters, trappers, or others who spend a great deal of time outdoors are at a greater risk of getting tularemia.
Causes and Transmission
People can get tularemia by:
- Being bitten by a dog tick, lone star tick, wood tick, or deer fly with tularemia bacteria.
- Touching animal tissue with tularemia bacteria.
- This is most common when hunting or skinning infected rabbits, muskrats, prairie dogs, and other rodents.
- It is important to be careful when handling any sick or dead animal.
- Breathing in dust or air particles with the bacteria. This can happen during farming or landscaping activities when tractors or mowers run over animals or carcasses with the bacteria.
- Having contact with an ill animal, including being bitten, scratched, or providing care.
- Eating rabbit or hare meat that is not fully cooked. Meat can still have the bacteria even after being frozen for several years.
- Drinking water that has the bacteria in it.
Tularemia cannot be spread from person to person.
Signs and Symptoms
Symptoms of tularemia start 2–10 days after the bacteria enters the body. The signs and symptoms can be different depending on where the bacteria enters the body.
Almost everyone who is sick with tularemia will have:
- Swollen lymph nodes in the area of the body near where the bacteria entered
Other signs and symptoms depend on how the tularemia bacteria entered your body:
- Insect bites, contact with infected tissue or animals, and animal bites or scratches:
- Skin sores
- Swollen lymph nodes usually in an arm pit or groin closest to the skin sore
- Touching the eye with unwashed hands that have the bacteria on them:
- Irritation and swelling of the eye
- Swollen lymph nodes in front of the ear
- Eating meat or drinking water with the bacteria:
- Sore throat
- Mouth sores
- Swollen tonsils
- Swollen lymph nodes in the neck
- Breathing in the bacteria (or other forms that are not treated):
- Chest pain
- Difficulty breathing
Symptoms of tularemia can look like other illnesses. If you have these symptoms, contact your doctor and be sure to tell them if you have had any recent tick or deer fly bites or contact with sick or dead animals.
Tularemia can be treated with antibiotics. Treatment is usually 10–21 days depending on the antibiotic used and how long you have been sick. It can take many weeks, but most people heal completely.
When spending time outdoors:
- Wear protective clothing—including long pants, long sleeves, and long socks.
- Use an Environmental Protection Agency (EPA)-registered insect repellent labeled for use against ticks and deer flies.
- Check your body for ticks after spending time outside. Remove attached ticks as soon as possible with narrow-bladed tweezers.
- Visit our Tick Bite Prevention page for more information on preventing bites.
- Do not drink untreated water.
When hunting, trapping, or skinning animals:
- Always wear gloves if you are skinning or handling animals, especially rabbits.
- Do not touch your eyes or mouth with dirty hands or gloves.
- Always wash your hands and equipment (knives, cutting boards) after you are done handling the animal.
- Cook meat from wild game thoroughly before eating.
When farming or landscaping:
- Be careful not to mow over sick or dead animals.
- Check the area for carcasses before mowing the lawn or using a tractor.
When interacting with animals that could be infected:
- Wear protective equipment, such as gloves.
- Avoid bites and scratches.
Reporting and Surveillance Guidance
This is a Wisconsin disease surveillance category II disease:
- Report to the patient's local public health department electronically, through the Wisconsin Electronic Disease Surveillance System (WEDSS), by mail or fax using an Acute and Communicable Disease case report, F-44151 (Word) or by other means within 72 hours upon recognition of a case.
- Information on communicable disease reporting
Wisconsin case reporting and public health follow-up guidelines:
Tularemia EpiNet, P-01911 (PDF): A tularemia case reporting and investigation protocol for health professionals.
Tularemia Information for Clinicians: CDC page with information on diagnostic testing, infection control and environmental decontamination, and treatment.
Questions about tularemia? Contact us!
Phone: 608-267-9003 | Fax: 608-261-4976