3. OCCURRENCE

Tularemia occurs throughout North America and in many parts of continental Europe, the former Soviet Union, China and Japan. In the USA, it occurs in all months of the year; incidence may be higher in adults in early winter during rabbit hunting season and in children during the summer when ticks and deer flies are abundant. F. tularensis biovar tularensis organisms, restricted to North America are common in rabbits (cottontail, jack and snowshoe), and are frequently transmitted by tick bite (see figure). F. tularensis biovar palaearctica strains are commonly found in mammals other than rabbits in North America; strains in Eurasia are found in voles, muskrats and water rats; and in rabbits in Japan.

ADDENDUM

Tularemia cases in the United States are no longer nationally notifiable.  Reporting was stopped at the end of 1994.  From 1990 to 1994, there were 152, 193, 159, 132, and 96 cases, respectively in the total United States. 

Source: MMWR 48(53) Supp, April 6, 2001.