Recent Changes Regarding

Rabies Exposure

By Marc Legris, MD

Rabies is a viral infection that is transmitted by the saliva of infected animals. The virus enters the central nervous system and is almost universally fatal. Fortunately, the rate of human rabies infections has significantly declined since 1950 in the United States. The number of human rabies cases in the United States was 18 in 1950 and in 1976 it was two. The decline is due to better control by local health authorities and immunization of domestic animals. However, the rate of rabies in wildlife in the continental United States has significantly increased since 1950. In currently comprises 85 percent of all documented cases in animals. Since 1980, of the 36 cases of human rabies in the United States, 21 of them have been due to bats alone.

It is a rare disease but up to 40,000 people each year receive treatment for possible rabies exposure. Rabies cannot be treated but it can be prevented. The best prevention is avoidance of wild animals that could possibly transmit the disease. Typically, wild terrestrial carnivores such as raccoons, skunks, foxes, coyotes, and opossum transmit the virus by scratches or bites. Unprovoked injuries from such animals (and injury while feeding wild animals is considered provocative) are more worrisome for rabies.

Rodents (such as squirrels, woodchucks, chipmunks, rats, or mice) and lagomorphs (such as rabbits) can carry rabies, but it is very rare and no cases of human rabies have ever been transmitted by these animals. Non-bite cases of rabies have been documented and these cases have been invariably due to bat exposures.

Of the 21 cases of bat transmitted rabies since 1980 in the United States, 12 cases have no bite or wound associated with the exposure. If exposure to a bat has occurred the best thing to do is collect the bat (obviously avoiding further contact to other persons) and submit the bat for rabies testing to the state health department laboratory.

If the bat cannot be collected safely, isolation of the bat and immediate collection by a professional exterminator or animal control expert is recommended. The following are examples of situations in which there is a reasonable probability of rabies exposure by a bat, which should be urgently evaluated by a medical provider:

*Young child touches a bat

*Older child or adult who touches a bat without seeing what part was touched

*A bat flies into someone and touches bare skin

*Young child reports being hit by a bat

*Stepping on a bat with bare feet

*Unidentified flying object hits person during twilight hours in an area known for bats

and causes injury

*Person awakens to find a bat in the room

*A bat found on the ground near a young child

*Person puts hand in woodpile and feels pain then sees a bat

Rabies prevention outside of animal control and avoidance can be provided by vaccination and antibody administration. Pre-exposure vaccination is reserved for high-risk job positions such as veterinarians and animal control professionals. Post-exposure vaccination and antibody administration is used for people who get a bite or scratch or mucous membrane exposure with saliva from the rabid animal.

People who have a high suspicion of exposure require treatment regardless of the delay in access to treatment and the sooner the better. It is not a medical emergency but rather a situation of medical urgency. Washing the exposure site with soap and water and if possible a virucidal agent such as iodine is the best initial measure.

An exposed person should get a single dose of rabies immune globulin (the antibody which fights the virus) up to day seven after starting the vaccine and starting the vaccine course. The vaccine is a series of 5 vaccines on days 1, 3, 7, 14, and 28. Local reactions to the vaccine are common and include redness, discomfort, and itching, with systemic reactions such as headache, nausea, abdominal cramps, and muscle aches less common. No serious side effects or transmission of human diseases (as these products are derived from humans) has ever been reported. Again, avoidance of wildlife that could potentially transmit rabies is the best way to protect yourself or your family. If you have a concern about rabies exposure call your doctor or your local health department.

The Newtown Health District phone number is 270-4291. Connecticut Department of health, 860/509-7994, for human rabies exposure questions; Connecticut Department of Environmental Protection, 860/424-3011, for questions on wildlife and rabies; and Connecticut Department of Agriculture, 860/713-2506, for questions on domestic animal exposures.

Dr Legris is a Danbury Hospital-affiliated family practice/pediatric physician, and member of the Danbury Office of Physicians Services, P.C. Dr Legris practices family/pediatric medicine at Brookfield Family Medicine with offices located in Brookfield and New Milford.