Tularemia is also known as “rabbit fever” and “deerfly fever” and is caused by infection with the bacteria Francisella tularensis, found throughout North America, Europe, and Asia. There are two subspecies of the bacteria, Type A, found in North America, and Type B found in Europe. Type A is highly virulent, whereas Type B causes milder forms of the disease. In the United States, approximately 200 human cases are reported each year, with less than 2% being fatal. Most cases occur in rural areas of the south-central and midwestern states during the summer months. From 1990 to 2000, 56% of all reported tularemia cases in the U.S. were in four states, Arkansas, Missouri, South Dakota, and Oklahoma.