Tularemia (redirected from rabbit fever)

Tularemia 

Definition

Tularemia is an illness caused by a bacterium. It results in fever, rash, and greatly enlarged lymph nodes.

Description

Tularemia infects a variety of wild animals, including rabbits, deer, squirrels, muskrat, and beaver. Humans can acquire the bacterium directly from contact with the blood or body fluids of these animals, from the bite of a tick or fly which has previously fed on the blood of an infected animal, or from contaminated food or water.

Tularemia occurs most often in the summer months. It is most likely to infect people who come into contact with infected animals, including hunters, furriers, butchers, laboratory workers, game wardens, and veterinarians. In the United States, the vast majority of cases of tularemia occur in the southeastern and Rocky Mountain states.

Causes and symptoms

Five types of illness may occur, depending on where/how the bacteria enter the body:

Diagnosis

Samples from the skin lesions can be prepared with special stains, to allow identification of the causative bacteria under the microscope. Other tests are available to demonstrate the presence of antibodies (special immune cells that the body produces in response to the presence of specific foreign invaders) which would be increasing over time in an infection with tularemia.

Treatment

Streptomycin (given as a shot in a muscle) and gentamicin (given as either a shot in a muscle or through a needle in the vein) are both used to treat tularemia. Other types of antibiotics have been tested, but have often resulted in relatively high rates of relapse (20%).

Prognosis

With treatment, death rates from tularemia are under 1%. Without treatment, however, the death rate may reach 30%. The pneumonia and typhoidal types have the worst prognosis without treatment.

Prevention

Prevention involves avoiding areas known to harbor ticks and flies, or the appropriate use of insect repellents. Hunters should wear gloves when skinning animals or preparing meat. Others (butchers, game wardens, veterinarians) who work with animals or carcasses should always wear gloves. A vaccine exists, but is usually only given to people at very high risk due to their profession or hobby (veterinarians, laboratory workers, butchers, hunters, game wardens).

Resources

Organizations

Centers for Disease Control and Prevention. 1600 Clifton Rd., NE, Atlanta, GA 30333. (800) 311-3435, (404) 639-3311. http://www.cdc.gov.

Key terms

Conjunctiva — The lining of the eyelids and the surface of the white part of the eye.

Shock — A state in which drastically low blood pressure prevents adequate blood flow to the tissues and organs throughout the body.

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tularemia /tu·la·re·mia/ (too?lah-re´me-ah) a plaguelike disease of rodents, caused by Francisella tularensis and transmissible to humans.

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oculoglandular tularemia  that in which the primary site of infection is the conjunctival sac, with conjunctivitis, corneal lesions, and enlargement of preauricular lymph nodes.

pulmonary tularemia , pulmonic tularemia that with involvement of the lungs by spread of primary infection or inhalation of the pathogen, with cough, fever, chest pain, and bloody sputum.

typhoidal tularemia  the most serious type, caused by swallowing the pathogen; symptoms are similar to those of typhoid.

ulceroglandular tularemia  the most common type in humans, beginning with a painful red papule at the point of inoculation, later forming a shallow ulcer; lymphadenopathy, hepatosplenomegaly, and pneumonia may also occur.

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tu·la·re·mi·a (tl-rm-)

n.

An infectious disease caused by the bacterium Francisella tularensis that chiefly affects rodents but can also be transmitted to humans, in whom it causes intermittent fever and swelling of lymph nodes.

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tularemia

a highly contagious disease of rodents caused by Francisella (Pasteurella) tularensis which may infect farm animals and humans. Biotype A, F. tularensis biovar tularensis, is prevalent in North America associated with tick-borne tularemia in rabbits and is more virulent than biotype B, F. tularensis biovar holarctica (palaearctica), which is found in Asia, Europe, and North America associated with mosquitoes and with water-borne disease in aquatic rodents and rarely causes disease in higher mammals. The clinical disease is very variable, depending on where the infection localizes.