Rationale:

• Bite wounds from animals up to date on rabies vaccination pose little risk of rabies transmission.
• Thorough cleansing of wounds may decrease the risk of rabies transmission.
• Most of the 50,000 or more human deaths per year that occur in developing countries from rabies are due to transmission from dogs.
• Rabies immune globulin provides immediate passive immunity, whereas active immunity takes 7 to 10 days to develop following vaccination.
• Both rabies vaccine and rabies immune globulin need to be administered to provide complete protection in individuals deemed to be at risk for rabies infection.
• Rabies can be identified in a population of dogs and cats in the U.S. but rarely is a cause of human rabies.
• Rapid incubation periods of less than 4 days have been reported in bite wounds to the head and neck, due to the proximity of the central nervous system.

Evidence:

• Animal data with experimental rabies infection in mice or guinea pigs have shown a decrease in rabies infection from 90% to approximately 5% to 10% with cleaning of superficial wounds 3 hours after exposure with 1% benzalkonium chloride, soap, or tap water (38).
• Of the 37 cases of human rabies diagnosed in the U.S. between 1981 and 1998, 12 were caused by dogs from foreign countries, although an exposure history was available in only 7 of 12 cases. Only 2 of the 25 cases acquired domestically were possibly caused by exposure to rabid dogs, whereas the remainder were due to bat variant rabies virus (42).
• A review found that 75% of animal-associated injuries in returning travelers occurred in countries endemic for rabies (43).
• Of the 7170 cases of animal rabies in the U.S. in 2003, 321 (4.5%) were in cats, and 117 (1.6%) were in dogs (44).
• Human rabies prevention is based on the recommendations of the Advisory Committee on Immunization Practices (45).

Comments:

• Most human rabies cases in the U.S. acquired without travel abroad are caused by bats.
• Reduce the risk of rabies transmission by immunizing dogs and cats. According to one survey, pet dogs and cats are under-immunized in the U.S., at rates of 59% and 41% respectively (46).
• The incidence of rabies in both cats and dogs in the U.S. has increased slightly since 2001, thus highlighting the importance of animal rabies vaccination.
• Administer preexposure rabies vaccine to high-risk groups, including veterinarians, animal handlers, certain laboratory workers, and people traveling to areas where dog rabies is enzootic and immediate access to appropriate medical care is limited.
• Test for adequate antibody response to rabies vaccination every 6 months in laboratory workers exposed to rabies virus and every 2 years in veterinarians and animal-control workers in rabies-enzootic areas.
• Administer booster rabies vaccine in high-risk workers with inadequate antibody titers detected on serologic testing.
• Preexposure vaccination lowers the risk of rabies transmission in high-risk individuals by decreasing the need for rabies immune globulin, especially when exposure may not be apparent and access to medical care is limited.