From Squirrels to Biological Weapons: The Early History of Tularemia.

After George McCoy accidentally discovered a new infection in 1911 while investigating bubonic plague in squirrels, he transmitted the disease to experimental animals and isolated the causative organism. He called it Bacterium tularense, after Tulare County, California. In 1919, Edward Francis determined that an infection called "deer-fly fever" was the same disease, naming it "tularemia." He demonstrated that it occurred in wild rabbits and inadvertently showed that it was highly infectious, for he and all his laboratory assistants contracted the illness. This characteristic led to studies of its potential as a biological weapon, including involuntary human experimentation by Japan among civilian, political and military prisoners, and its probable use in warfare during World War II. Later, in the United States, voluntary human experimentation occurred in the 1950s-1960s with penitentiary inmates and non-combatant soldiers. Soviet Union scientists allegedly developed a vaccine-resistant strain, which they tested as a biological weapon in 1982-1983.