Tularemia is a disease of animals and humans caused by the bacterium Francisella tularensis. Rabbits, hares, and rodents are especially susceptible and often die in large numbers during outbreaks.
In the 1950s, thousands of people were infected each year. This number has dropped considerably, to less than 200 each year, and those who are infected now tend to be those who are exposed to the organism in its rural habitat.
The drug of choice for tularemia treatment has historically been streptomycin or tetracycline-class drugs such as doxycycline. Gentamicin may also be used as it is easier to obtain than streptomycin.
The CDC has been investigating the cases and their possible causes, which include enterovirus D-68 (EV-D68), the source of a respiratory illness outbreak involving 1,116 cases in recent months, nearly all of them in children.