In 1953, the U.S. Centers for Disease Control and Prevention (CDC) reported the first transmission of rabies by a bat. Rabid insectivorous bats have caused an average of 700 to 800 cases annually, and have been found throughout the United States, excluding Alaska and Hawaii.

Rabies prevention and control strategies have succeeded in lowering the number of human rabies deaths to an average of 1-2 per year. The prevention program was estimated to cost $230 million to $1 billion per year. This cost was shared by the private sector (vaccination of companion animals) and the public (through animal control programs).

The public health threat of rabies as a preeminent zoonosis relates to the acute, incurable encephalitis that results from transmission of the virus by the bite of an infected animal. An estimated 40,000 to 100,000 human deaths are caused by rabies each year worldwide; in addition, millions of persons, primarily in developing countries of the subtropical and tropical region.