Overview

Approximately 200 cases of tularemia in humans are reported annually in the United States, mostly in persons living in the south-central and western states. Tularemia is an occupational risk for farmers, foresters, and veterinarians, and is listed by the U.S. Centers for Disease Control and Prevention (CDC) as one of the six category A, or high-priority, biological warfare agents. Nearly all cases of tularemia occur in rural areas and are associated with the bites of infected ticks, mosquitoes, and biting flies or with the handling of infected rodents, rabbits, or hares. Less commonly, tularemia can be contracted through ingestion of contaminated food or water or by inhalation. Release of the bacteria in a aerosolized form is the most likely method to be used in bioterrorism. Tularemia is extremely infectious. Relatively few bacteria are required to cause the disease, which is why it is an attractive weapon for use in bioterrorism.