ABSTRACT
Tularemia is a zoonotic disease caused by the bacterium, Francisella tularensis. Though the organism was Šrst isolated from ground squirrels in Tulare County, California, in 1912,1 reports of a tularemia-like disease in both animals and humans in the United States, Japan, and Norway surfaced much earlier.2 F. tularensis is found throughout the Northern Hemisphere and has been documented in hundreds of invertebrate and vertebrate species.3,4 The organism is highly infectious: a dose as low as 10 cells can cause disease.5,6 Humans are incidental hosts and clinical presentation and severity depend on the route of organism entry and strain type. Transmission occurs via arthropod bite, inhalation, ingestion of the organism or direct skin contact with infected tissues.5,7,8 Because of its infectious nature and potential to cause signiŠcant morbidity, F. tularensis was part of offensive biological weapons programs in the mid-twentieth century, and is considered a high priority potential bioweapon.9
