Bats and Halloween go together like peanut butter and jelly. However, there is another not so festive association between bats and rabies, a lethal viral infection.
1. Let’s start with the good news. Human rabies is very rare in the United States, averaging no more than a few cases per year.
2. Many animal species can carry and transmit rabies to humans, usually through a bite. Insectivorous bats (bats that eat insects) are the only species in which the rabies virus in endemic in the contiguous 49 States; Hawaii has thus far remained rabies free. This means that there are bats in Maine infected with the rabies virus. The majority of bats, however, are not infected with rabies.
3. Rabies may bring to mind an image of a dog foaming at the mouth. However, bats are the biggest culprit in transmission of rabies to humans in the United States. Whereas bites from other wild (or domestic) animals are obvious, that may not be the case for bats. The bite of some bats can be so subtle as to go unnoticed, and a superficial bite or scratch from these bats may be enough to result in infection.
For example, there were 34 bat-associated human cases of rabies reported in the US from 1990 -2007.
6/34 had a reported bite
2/34 had reported contact with a bat and a probable bite
15/34 physical contact was reported but no bite (removal of bat from workplace/home or presence of bat in a room where a person had been sleeping)
11/34 no bat encounter reported but an undetected bat bite is the presumed source of rabies based on the DNA of the rabies viruses matching that of a specific species of bats
For other animals, protecting yourself against the (unlikely) chance of getting rabies is pretty straightforward. If a person is bitten by any animal, they should seek care immediately and receive preventative treatment if needed. Pets should also receive appropriate rabies vaccinations.
To protect against bat exposure, avoid close proximity to bats, especially indoors. In any situation where a bat is physically present and you cannot rule out having been bitten, safely capture the bat (if possible) for rabies testing and seek medical attention immediately. If a bat has been found in the room where someone has slept or a child or mentally impaired person was unattended, or a person was intoxicated, you should seek medical attention immediately. Again, if possible, capture and have the bat tested. Bats are more likely to be rabid if they are active by day, found in an unusual place (inside a room, on a lawn), or unable to fly. According to the CDC, all bats potentially involved in a human exposure should be caught and sent for testing whenever possible.
Bats aren’t bad guys!! They are an interesting and valuable part of the ecosystem. An especially beneficial behavior of bats in Maine is that they love to eat mosquitoes. Seeing bats outside is not dangerous, and even bats living in buildings (example= empty attic) don’t automatically need to be evicted. However, they should always be prevented from entering rooms. There are professional services available for “bat-proofing” as well as techniques for do-it-yourselfers at the web sites below, plus a wealth of information on rabies and bats in general. Happy Halloween!
References
1. Morbidity and Mortality Weekly Report. Human Rabies Prevention – United States, 2008. Recommendations of the Advisory Committee on Immunization Practices. Department of Health and Human Services Centers for Disease Control and Prevention. May 7, 2008/Vol.57. www.cdc.gov/mmwr
2. www.cdc.gov/rabies/bats.htm