June 04, 2008

Rabies Season Begins - Use Caution!

Spring is the time of year when bats and other wild animals come out of hibernation. Some of these animals - especially bats - may be infected with the rabies virus. Already this spring the Central District Health Department (CDHD) has investigated two human-bat interactions. Tests performed on both bats found they were not rabid. Still, the incidents serve as a warning to those entering cabins and out buildings that have been closed for the winter. Everyone should exercise caution when encountering potentially infected animals.

In Idaho, only bats are known to be natural reservoirs for rabies. However, bats are not the only animal of interest when it comes to rabies. All mammals may become infected with rabies and ALL mammals should be considered potentially rabid when they bite, scratch or otherwise expose people or pets to their saliva.

Between 1999 and 2007 an average of 17 bats (range of 5 – 38) per year, or 10.6% of bat submissions, tested positive for rabies by the Idaho Department of Health and Welfare Bureau of Laboratories.

This data includes only animals that actually were submitted for testing to the Idaho Bureau of Laboratories; the actual number of rabid bats (and other species) in Idaho is likely much higher. Rabid bats have been reported from almost all parts of Idaho and have been detected from May to November.

A handful of other species in Idaho have also been documented as having the bat strain of rabies. Because other mammals have tested positive for rabies, the risk of rabies exposures from bites, scratches, or other exposures from mammals other than bats must not be ignored as a possible source of rabies.

An added level of concern came on May 19th when Sanofi Pasteur, maker of IMOVAX Rabies (Rabies Vaccine), announced the vaccine would temporarily only be available for post-exposure prophylaxis. People seeking to immunize themselves before travel may have to wait until more vaccine becomes available. Sanofi Pasteur expects to be able to offer additional vaccine by July 2008. In light of the current shortage of rabies vaccine it is more important that ever for the public to avoid exposure to potentially infected wild animals.

Rabies virus infects the central nervous system, causing degeneration of the brain and ultimately death. Early symptoms of rabies in humans are nonspecific, consisting of fever, headache, and general feeling of illness. As the disease progresses, neurological symptoms appear and may include insomnia, anxiety, confusion, slight or partial paralysis, excitation, hallucinations, agitation, excess salivation, difficulty swallowing, and hydrophobia (fear of water). Death usually occurs within days of the onset of symptoms.

Rabies can be confirmed only in a laboratory. However, any bat that is active by day, is found in a place where bats are not usually seen (for example, in a room in your home or on the lawn), or is unable to fly, is far more likely than others to be rabid. Such bats are often the most easily approached. Therefore, it is best never to handle any bat.

If you are bitten by a bat -- or if infectious material, such as saliva, from a bat gets into your eyes, nose, mouth, or a wound -- wash the affected area thoroughly and get medical advice immediately. Whenever possible, the bat should be captured and sent to a laboratory for rabies testing.

Most types of bats have very small teeth which may leave marks that disappear quickly. There are situations in which you should seek medical advice even in the absence of an obvious bite wound. For example, if you awakened because a bat landed on you while you were sleeping, if you awakened and found a bat in your room, if you see a bat in a room with an unattended child, or see a bat near a mentally impaired or intoxicated person, try to safely capture the bat and have the bat tested, and seek medical advice.

People cannot get rabies just from seeing a bat in an attic, in a cave, at summer camp, or from a distance while it is flying. In addition, people cannot get rabies from having contact with bat guano (feces), blood, or urine, or from touching a bat on its fur (even though bats should never be handled!).

For more information on rabies, the vaccine and what to do if you are exposed to an animal that may be rabid, visit the CDC website.