Should you vaccinate? Consider these factors

Consider the nature of the exposure, the severity of the bite, disposition of the animal, and species when deciding whether to administer a rabies vaccine, stresses Charles Rupprecht, VMD, MS, PhD, chief of the Centers for Disease Control and Prevention’s (CDC) Rabies Section and director of the World Health Organization’s Collaborating Center for Reference and Research on Rabies, both based in Atlanta.

Work with an infectious disease physician on staff at the hospital or local and state public health departments to assess the potential for rabies exposure, he recommends. Here are factors to consider:

Availability of the animal for observation.

Patients often are given rabies vaccines when they’re not necessary, Rupprecht says.

"When an owned, well-supervised, vaccinated, and apparently healthy dog bites someone after provocation and is available for observation, that is inappropriate for PEP [post-exposure prophylaxis regimens]," he says. "Given how common dog bite is, one should not be giving PEP automatically."

Any transdermal or mucous membrane exposure from a potentially rabid mammal constitutes an exposure, Rupprecht explains. "But if the dog, cat, or ferret is in hand, the animal should be observed for a 10-day period. If the animal remains healthy, it was not presumed to be infectious at the time the exposure occurred."

If the animal is wild and not domestic, or is not available for observation, public health officials should be contacted to determine the likelihood of rabies, advises Rupprecht. Consider the following points:

— Was the bite provoked?

— What was the severity of exposure (bite or nonbite)?

— Was the animal apparently healthy at the time?

— What are the local rabies statistics? Those statistics should be available at your local or state health department.

Region. The way an animal bite is managed when a dog is unavailable for testing can vary widely in different parts of the country, Rupprecht explains. "In the Pacific Northwest, where the incidence of rabies may be very low, it’s a much different situation than in areas where we share a border with Mexico and free-ranging dogs could cause the incidence of rabies to be higher."

• Species. Even among wild species, an animal bite may not constitute rabies exposure. "Rodent bites are quite common especially in large cities, but there has never been a recorded case of rabies transmission from rodent to person," says Rupprecht. Raccoons, skunks, foxes, bats, and coyotes are the animals most often infected with rabies, he notes.

• Side effects of vaccines. Although the rabies vaccines are very safe, several side effects can occur. "These haven’t been life-threatening, but can range from uncomfortable to temporarily incapacitating," says Rupprecht. "Nobody wants a needle with a foreign antigen to be inoculated in their arm if it is not necessary."

Adverse effects include local pain and swelling, risk of fever and nausea, and in some cases, a delayed hypersensitivity reaction, he notes.