This document presents the characteristics, diagnosis, and treatment of tularemia.
Tularemia is a zoonosis caused by the Gram-negative, facultative intracellular bacterium, Francisella tularensis. The disease is characterized by fever, localized skin or mucous membrane ulceration, regional lymphadenopathy, and, occasionally, pneumonia. It was discovered in 1911 as a cause of a plague-like illness in ground squirrels. The first human case was reported in 1914. F tularensis has been considered an important biological warfare threat because of its very high infectivity after aerosolization. The principal reservoir of tularemia in North America is the tick; more than ten species have been implicated. F tularensis is usually introduced into the host through breaks in the skin, or through the mucous membranes of the eye, respiratory tract, or gastrointestinal tract. Tularemia can be diagnosed by recovery of F tularensis in culture, or from serologic evidence of infection in a patient with a compatible clinical syndrome. Patients with tularemia who do not receive appropriate antibiotic treatment may have a prolonged illness characterized by malaise, weakness, weight loss, and other symptoms that last for months. With appropriate treatment, tularemia has an overall mortality of approximately one percent to 2.5 percent. Streptomycin is the drug of choice for the treatment of tularemia. Patients treated with streptomycin usually respond within 48 hours of its administration. Immediate postexposure antibiotic prophylaxis with tetracycline prevents disease. A live, attenuated vaccine, available as an Investigational New Drug, is effective against aerosol infection. 99 references