FAMILY MEDICINE® COLUMN
By John C. Wolf, D.O.
Associate Professor of Family Medicine®
Ohio University College of Osteopathic Medicine

BAT HOUSES ARE A GOOD IDEA -- BUT DON'T STICK YOUR HAND IN ONE!

Question: My neighbor has a "bat house" in his yard. I think it is a bad idea to encourage bats to be around humans because of the risk of rabies. He laughs at my concern and says that they are beneficial because of the large number of insects they eat. What do you think?

Rabies is a serious viral illness that attacks the central nervous system of infected humans and ultimately results in death. The virus is acquired by exposure to the saliva of infected mammals, usually from a bite. It has never been a particularly common illness for humans, but it is relatively frequent in animals. Because we humans come in contact with other animals, including bats, the risk of rabies remains real.

The magnitude of the rabies risk, particularly from bats, is a concern best expressed by the reality of numbers. Since 1980 there have only been 36 reported cases of rabies in humans in the United States. Therefore, the real risk of you or me actually getting rabies within the next year is considerably less than either of our chances for hitting the Super Lotto. On the other hand, of those 36 cases of rabies that have been reported to the Centers for Disease Control and Prevention, 21 -- or nearly 60 percent -- were due to bats. The bat origin of the disease has been confirmed, according to the CDCP, by either analysis of viral DNA on autopsy of the victims or a history of a bat bite, or both.

Despite the low occurrence of human rabies, between 16,000 and 39,000 people require "rabies shots" each year after having been bitten by a potentially infected animal. Bites from a neighborhood dog, though unfortunately frequent, have low risk of rabies because of the required rabies vaccinations of dogs in our country. More frequent carriers of this deadly virus are wild animals, particularly raccoons, skunks, bats and groundhogs. The deadly consequences of rabies can be prevented by treatment. This consists of a series of shots given after the bite but before any symptoms of the disease appear -- a procedure called post-exposure vaccination. Once symptoms begin, the disease cannot be treated and is uniformly fatal! Rabies shots were once quite painful. Fortunately, this has improved, but they still aren't pleasant. In addition, they are quite expensive. The necessary series costs between $1,000 and $2,000! Consequently, rabies shots should only be used when necessary.

A bite from a healthy appearing and previously immunized neighborhood dog has almost no risk of rabies and makes post-exposure vaccination unnecessary. A bite from an obviously sick dog, cat or ferret, or a bite from any skunk, raccoon, fox, bat or other wild carnivore is another matter. Your doctor will want either confirmation through laboratory tests on the animal that it was not rabid, or he or she will begin giving you the rabies vaccine shots promptly.

The current recommendation for vaccination after exposure to bats is a bit different. This is probably because it is possible to be bitten by a bat and not realize it. According to the CDCP, shots are recommended in the following situations, unless the bat can be captured for study: * You awaken to find a bat in your room, or * A bat is discovered in the room of a child or of an adult with reduced mental capacity -- including from drugs or alcohol. Remember that simply seeing a bat can't give you rabies. Workers in rabies research laboratories, veterinarians, animal control officers and spelunkers are at higher risk and should consider pre-exposure rabies immunizations.

So back to your discussion with you neighbor. The number of insects a bat consumes over the course of a summer is astounding. Therefore, I think that bat houses are a good idea, but I sure wouldn't put one by my bedroom window, simply because my screen sometimes falls out. One in the yard, as your neighbor has, poses almost no risk to you or your family.

Family Medicine® is a weekly column. To submit questions, write to John C. Wolf, D.O., Ohio University College of Osteopathic Medicine, Grosvenor Hall, Athens, Ohio 45701.