Rabies is a viral disease affecting the central nervous system that is nearly always fatal once symptoms develop. The virus spreads through the saliva of infected mammals, typically through a bite or scratch. In the United States, bats are the most common source of human rabies cases, highlighting the serious nature of finding one inside a dwelling. Since the disease is preventable only through immediate medical intervention, prompt action is required whenever a bat exposure is possible.
Immediate Steps and Safe Bat Management
The most important step upon finding a bat indoors is to ensure it is captured for rabies testing, if any chance of exposure exists. Contact your local public health department or animal control immediately to report the presence of the bat and receive guidance. Do not attempt to release the bat outside, as testing is the only way to definitively determine if post-exposure prophylaxis (PEP) is necessary for any occupants.
To safely contain a bat, put on thick leather work gloves to prevent accidental contact. Wait until the bat is still, then gently place a container, such as a large jar or coffee can, over the animal. Slide a piece of stiff cardboard or plastic underneath to trap the bat inside the container, securing the lid or taping the cardboard to the rim. Avoid damaging the bat’s head, as the brain tissue must be intact for successful laboratory testing.
Place the sealed container in a cool place, such as a refrigerator, until it can be transported for testing. Do not put the container in a freezer, as freezing compromises the brain tissue and makes the rabies test unreliable. Following these steps allows public health officials to quickly test the animal, potentially saving people the expense and inconvenience of unnecessary medical treatment.
Determining the Risk of Rabies Exposure
The decision to recommend the rabies shot hinges on whether exposure is presumed to have occurred, which is complicated because bat bites are often tiny and not easily visible. Bats possess small, sharp teeth that can leave a puncture mark so minute a person may not feel or notice it. This creates a situation known as “unwitnessed exposure,” the primary reason for concern when a bat is found inside a home.
Public health guidelines state that exposure is presumed and post-exposure prophylaxis (PEP) is recommended in specific scenarios where direct contact cannot be ruled out. This includes finding a bat in a room with a person who was asleep, a young child, or an individual who is cognitively impaired or intoxicated. In these situations, the person may not be able to reliably confirm whether a bite or scratch occurred, and the risk is considered too high.
If the bat is successfully captured and testing confirms it is negative for rabies, no further action is typically necessary for potentially exposed people. However, if the bat is unavailable for testing—for example, if it escapes or is released—and unwitnessed exposure is suspected, health officials will recommend the exposed individual begin the full PEP regimen. The decision on PEP is always made in consultation with a healthcare professional and the local public health department.
Understanding Post-Exposure Prophylaxis (PEP)
If exposure is confirmed or presumed, the medical intervention required is Post-Exposure Prophylaxis (PEP), which is nearly 100% effective when administered promptly before symptoms begin. The treatment involves two components that prevent the virus from reaching the central nervous system. The first component is Human Rabies Immune Globulin (HRIG), which provides immediate, passive immunity by supplying ready-made antibodies to neutralize the virus at the site of entry.
HRIG is administered only once, typically by infiltrating the area around the wound or suspected exposure site. Any remaining volume is injected into a muscle site distant from the vaccine injection. The second component is the rabies vaccine series, which provides long-lasting, active immunity by prompting the body to produce its own antibodies. This series consists of four intramuscular doses given over a two-week period.
The standard vaccine schedule for a person who has never been immunized against rabies is a dose on the day of exposure (Day 0), followed by additional doses on Days 3, 7, and 14. Modern rabies vaccines are given as a standard injection into the deltoid muscle of the arm for adults and older children, or the anterolateral thigh for very young children.
This modern protocol has replaced the older, painful injections once rumored to be given in the stomach. This change makes the treatment much more tolerable.
It is necessary to complete the full four-dose series once PEP is initiated to ensure a robust and lasting immune response. Although the treatment remains effective even if there is a slight delay, it should be started as soon as possible after the exposure risk is determined. If a person has been previously vaccinated against rabies, they require only two vaccine doses and do not receive the immune globulin.