Tularemia is a serious infectious disease caused by the intracellular bacterium Francisella tularensis. A Gram-negative pleomorphic coccobacillus, the bacterium has several subspecies with varying degrees of virulence.
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.
Treatment usually lasts 10 to 21 days depending on the stage of illness and the medication used. Although symptoms may last for several weeks, most patients completely recover.
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.