Tularemia is an infection common in wild rodents. It is passed to humans through contact with tissue from the infected animal. It can also be passed by ticks, biting flies, and mosquitoes.
Tularemia is caused by the bacterium Francisella tularensis.
Humans can get the disease through:
- A bite from an infected tick, horsefly, or mosquito
- Breathing in infected dirt or plant material
- Direct contact, through a break in the skin, with an infected animal or its dead body (most often a rabbit, muskrat, beaver, or squirrel)
- Eating infected meat (rare)
The disorder most commonly occurs in North America and parts of Europe and Asia. In the US, this disease is found more often in Missouri, South Dakota, Oklahoma and Arkansas. Although outbreaks can occur in the United States, they are rare.
Some people may develop pneumonia after breathing in infected dirt or plant material. This is known to occur on Martha's Vineyard, where bacteria are present in rabbits, raccoons, and skunks.
Symptoms develop 3 to 5 days after exposure. The illness usually starts suddenly. It may continue for several weeks after symptoms begin.
Exams and Tests
Tests for the condition include:
- Blood culture for tularemia bacteria
- Blood test measuring the body's immune response to the infection (serology for tularemia)
- Chest x-ray
- Polymerase chain reaction (PCR) test of a sample from an ulcer
The goal of treatment is to cure the infection with antibiotics.
Streptomycin and tetracycline are commonly used to treat this infection. Once daily gentamicin treatment has been tried with as an alternative to streptomycin. This medicine appears to be very effective but it has been studied in only a few cases because this is a rare disease. Tetracycline and chloramphenicol can be used alone but not used as a first choice.
Note: Oral tetracycline is usually not prescribed for children until after all their permanent teeth have come in. It can permanently discolor teeth that are still forming.
Tularemia is fatal in about 5% of untreated cases, and in less than 1% of treated cases.
When to Contact a Medical Professional
Call your health care provider if symptoms develop after a rodent bite, tick bite, or exposure to the flesh of a wild animal.
Preventative measures include skinning or dressing wild animals with gloves and avoiding sick or dead animals.
Deerfly fever; Rabbit fever; Pahvant Valley plague; Ohara disease; Yato-byo (Japan); Lemming fever
Penn RL.Francisella tularensisMandell, Douglas, and Bennett's Principles and Practice of Infectious Disease
Schaffner W. Tularemia and other Francisella infections. In: Goldman L, Schafer AI, eds.Goldman's Cecil Medicine
Update Date 1/29/2013
Updated by: Jatin M. Vyas, MD, PhD, Assistant Professor in Medicine, Harvard Medical School; Assistant in Medicine, Division of Infectious Disease, Department of Medicine, Massachusetts General Hospital, Boston, MA. Also reviewed by A.D.A.M. Health Solutions, Ebix, Inc., Editorial Team: David Zieve, MD, MHA, Bethanne Black, Stephanie Slon, and Nissi Wang.