Tularemia is an uncommon but potentially fatal zoonotic disease caused by the gram-negative coccobacillus Francisella tularensis. Approximately 40 percent of all tularemia cases reported to CDC each year occur in Arkansas, Oklahoma, and Missouri. Tularemia is a nationally notifiable disease. Although tularemia was removed from the list of nationally notifiable diseases in 1994, it was reinstated in 2000 because of increased concern about potential use of F. tularensis as a biologic weapon.

The clinical presentation of tularemia ranges from cutaneous ulcers to pneumonia and depends on the mode of transmission and site of inoculation. Routes of F. tularensis transmission to humans include arthropod bites, contact with infected animal tissues, ingestion of contaminated food or water, and inhalation of contaminated aerosols (e.g., aerosols generated by mowing over infected animal carcasses and through improper handling of laboratory cultures).

The Missouri Department of Health and Senior Services (MDHSS) analyzed surveillance data and conducted a retrospective clinical chart review of cases that occurred during 2000--2007. For the 26 cases categorized as pneumonic tularemia based on clinical features, 12 (had recorded exposures, of which six were inhalational (four patients worked with grain or hay; two mowed over dead animals) and six were tick exposures (without lesions or lymphadenopathy).

The prevention of tularemia requires educating those at greatest risk for exposure (e.g., hikers, campers, and hunters). The use of protective clothing, repellents containing DEET (N,N-dimethyl-meta-toluamide), and pesticides (e.g., permethrin) on clothing can help reduce the risk for exposure through tick and arthropod bites (3). Hunters and others who handle potentially infected animals should wear gloves to avoid introduction of F. tularensis through cuts or abrasions, and game meat should always be cooked thoroughly. To reduce the risk for aerosol exposures, grassy areas should be surveyed before mowing and any dead animals removed. Persons facing potential occupational risks such as agricultural and laboratory workers should follow safe practice guidelines.

Read the full report from the CDC's Morbidity and Mortality Weekly Report