Worldwide, approximately 50,000 deaths per year are caused by rabies, but a firm estimate is hard to come by because reporting mechanisms in many developing countries where rabies is endemic are unreliable or nonexistent. In many parts of the world, lack of funding and logistics prevent widespread canine vaccination, and dog bites remain the primary vector for rabies infection in humans. Wilde and colleagues review updated advice for travelers who may be at risk of exposure to rabies.
Bites to the head and neck appear to confer a higher risk of developing rabies, and about 40 percent of all patients who develop rabies are children 15 years and younger. Appropriate treatment after a bite is not available in many tourist destinations. The human diploid cell vaccine used in the United States is expensive. Less costly rabies vaccines produced in developing countries from nerve tissue–derived sources (i.e., Semple and suckling mouse brain vaccines) have had unreliable potency and can carry the risk of residual live rabies virus. The World Health Organization (WHO) has approved two economical tissue-culture vaccines (i.e., purified Vero cell vaccine and purified chick embryo cell vaccine) that are as safe and effective as human diploid cell vaccine.
Optimal treatment after an animal bite includes immediate washing of the wounds with copious amounts of water and antiseptic solution (i.e., alcohol, povidoneiodine). Human or equine rabies immunoglobulin should be given if any wounds penetrate the skin. The immunoglobulin should be injected into and around all wound sites to neutralize the rabies virus before it can enter a peripheral nerve. Ideally, immunoglobulin is administered within 24 hours of exposure and should be given no later than one week postexposure; after that time, it theoretically may suppress the patient's immune response to rabies infection. Rabies immunoglobulin is expensive and not widely available in Asia and Africa.
Following rabies immunoglobulin administration, all patients should receive a WHO-approved vaccination series. The authors note that vaccination alone is likely to prevent the majority of rabies deaths, but that any patient with deep or multiple wounds in nerve-rich areas (e.g., head, hands) also should receive rabies immunoglobulin if possible. A variety of intramuscular and intradermal rabies vaccination schedules are used worldwide.
Pre-exposure prophylactic vaccination may be considered for travelers such as backpackers and those planning extended stays or travel to rural areas, who are more likely to be in contact with stray dogs or other rabid animals. Previously vaccinated patients do not require immunoglobulin after a bite, but they do need to have two booster vaccinations, given on days zero and 3 after exposure. The authors suggest that travelers at higher risk for exposure obtain contact information before departure about reliable treatment centers if an emergency should arise. Additional information may be obtained at the following Web site:http://www.cdc.gov/travel andhttp://www.who.int/ith.