Animal Rabies: Implications for Diagnosis and Human Treatment

As a result of urban vaccination of dogs in the 1940s, endemic dog rabies in the United States was eliminat-ed, and the number of rabid wild animals now far exceed the number of rabid dogs. Today thousands of rabid skunks and raccoons (but fewer than 200 rabid dogs—a fraction of the number in the 1940s) are re-ported annually. With the decrease in the number of rabid dogs came a corresponding drop in human ra-bies, from dozens of cases to less than one per year. The current U.S. rabies epizootic is really a series of outbreaks in various species—mostly skunks, rac-coons, and bats, with many secondary cases in cattle, dogs, cats, and occasionally other wild and domestic animals (1, 2). Thus exposures to these animals are potentially life threatening and result in the adminis-tration of rabies prophylaxis after exposure to over 18 000 persons annually. Other expenses related to ra-bies, especially canine and feline vaccination, bring the total estimated cost of rabies in the United States to over $300 million per year (3). This routine veterinary vaccination protects dogs and cats exposed to rabid wild animals. In addition, because most human treat-ment still results from exposure to dogs (4) , canine vaccination has the potential to prevent the need for many human treatments. The proper administration of human rabies prophy-laxis after exposure (5) virtually guarantees complete protection against the disease; no one who has re