Rabies is a serious viral disease often associated with bats, a connection that can cause concern. While bats are a known reservoir for the rabies virus, not every bat carries rabies. Only a small percentage of bats are infected, making fear of all bats an unnecessary response.
Why Bats are Unique Carriers
Bats serve as natural reservoirs for various strains of the rabies virus, a type of lyssavirus. They can become infected through bites from other rabid bats. While lethal to bats, their unique biology allows them to carry the virus for extended periods without showing severe illness or dying rapidly. This ability stems from their distinct immune systems.
The high metabolic rates and elevated body temperatures bats experience due to flight contribute to their immune response. This robust immune system helps them manage viral infections, including rabies, more effectively than many other mammals. Infected bats can sometimes shed the virus before succumbing to the disease, making them effective carriers. Only a small fraction, typically less than one percent, of the bat population is infected with rabies.
Understanding Transmission and Risk
Rabies is primarily transmitted from bats to humans or other animals through a bite or scratch from an infected bat. The virus, concentrated in the bat’s saliva, enters the body through broken skin. Direct contact between infected saliva and mucous membranes, such as the eyes, nose, or mouth, or an open wound can also lead to transmission.
A challenge with bat-related rabies exposure is that bat bites can be very small and might not be easily noticeable. Due to their tiny teeth, a person might not even realize they have been bitten, especially if they are asleep or impaired. While human rabies cases from bats are low, with zero to two human deaths per year in the United States, the disease is almost always fatal once symptoms appear.
Unusual behavior in a bat can indicate potential rabies infection, though laboratory testing is the only definitive way to confirm it. Bats that are active during the day, found in unusual locations like inside a home or on the ground, or appear unable to fly or easily approached may be rabid. Such behaviors suggest the bat is ill and should not be approached.
Prevention and Response to Exposure
Preventing rabies exposure from bats involves avoiding direct contact and securing living spaces. Never handle bats directly. Ensuring pets, especially dogs and cats, are up-to-date on their rabies vaccinations provides protection. Preventing bats from entering homes can be achieved by “bat-proofing” structures, sealing openings as small as a quarter-inch, and installing screens on windows and chimneys.
If a potential exposure occurs, such as a bite or scratch from a bat, or if a bat is found in a room with a sleeping person, an unattended child, or someone unable to communicate an exposure, immediate action is necessary. The wound should be thoroughly washed with soap and water for at least 15 minutes. Seek immediate medical attention for post-exposure prophylaxis (PEP). PEP typically involves a series of rabies vaccine injections and, for those not previously vaccinated, an administration of human rabies immune globulin (HRIG).
Whenever possible and safe, the bat should be captured for rabies testing. This can help determine if PEP is truly needed, as treatment may not be required if the bat tests negative. To safely capture a bat, wear thick leather gloves, place a container over it, and slide cardboard underneath to trap it. Contact local animal control or public health officials for assistance and to arrange for testing; it is important not to release or discard the bat if potential exposure has occurred.