Deerfly fever; Tularemia
Tularemia is an infection common in wild rodents caused by the organism Francisella tularensis and transmitted to humans by contact with animal tissues or ticks.
Causes, incidence, and risk factors
Humans can contract tularemia in the following ways:
- direct contact with an infected animal or carcass via broken skin
- the bite of an infected flea or tick
- ingesting infected meat (rare)
Endemic areas (areas where the disorder occurs most commonly) include North America and parts of Europe and Asia. The illness may continue for several weeks after the onset of symptoms.
Some people may develop an atypical pneumonia. Risk factors include recent exposure to rabbits or recent a tick bite. The disease is very rare in the United States.
Francisella tularensis is considered a potential bioterrorism agent. An aerosol release would be the most likely method and would result in a large number of pneumonia cases several weeks after exposure.
- red spot on the skin, enlarging to an ulcer
- enlarged lymph nodes of groin or armpits
- muscle pains
- possible conjunctivitis
- shortness of breath
- weight loss
- joint stiffness
Signs and tests
- serology for tularemia
- blood culture for tularemia
- chest X-ray
This disease may also alter the results of febrile/cold agglutinins.
The goal of treatment is to eliminate the infection with antibiotic therapy. Streptomycin and tetracycline are commonly used in this infection.
Note: oral tetracycline is usually not prescribed for children until after all the permanent teeth have erupted. It can permanently discolor teeth that are still forming.
Tularemia is fatal in about 5% of untreated cases and in less than 1% with treatment.
Calling your health care provider
Call your health care provider if symptoms develop after a rodent bite, tick bite, or exposure to the flesh of a wild animal.
A vaccine is recommended for people at high risk (trappers, hunters, and laboratory workers who work with the organism).
by Armen E. Martirosyan, M.D.