Rabies is a severe viral disease impacting the central nervous system of mammals, including humans. Once clinical symptoms manifest, the disease is almost always fatal. The virus typically spreads through the saliva of an infected animal, most often when the virus enters the body through a bite.
Understanding Rabies Transmission
The rabies virus resides in the saliva of an infected animal. Transmission primarily occurs when this infected saliva penetrates the skin, commonly through a bite wound. Less frequently, the virus can spread through scratches that break the skin, or when saliva comes into contact with mucous membranes, such as the eyes, nose, or mouth. For the virus to cause infection, it must successfully enter the body’s tissues.
In the United States, wildlife accounts for over 90% of reported rabies cases in animals. The animals most frequently identified with rabies include bats, raccoons, skunks, and foxes. Globally, domestic dogs are the primary source of human rabies cases, accounting for over 95% of estimated human deaths annually.
Rabies Risk in Small Rodents
It is extremely rare for small rodents, such as field mice, rats, squirrels, hamsters, guinea pigs, and chipmunks, to transmit rabies to humans. These small animals are highly unlikely to survive an attack from a rabid predator, such as a fox or skunk, long enough to develop the disease and subsequently transmit it.
The Centers for Disease Control and Prevention (CDC) rarely reports rabies in these small rodents. When found, it typically occurs under very unusual circumstances, such as laboratory exposure. There are no documented cases of human rabies deaths in the United States linked to exposure from rodents or lagomorphs (rabbits and hares).
Bites from these small rodents are generally not considered a rabies risk. However, an exception might be if the animal exhibits highly unusual behavior, such as unprovoked aggression, paralysis, or appears overtly sick. In such rare instances, consult public health authorities. Woodchucks, also known as groundhogs, represent an exception among rodents, occasionally accounting for a notable percentage of rabid rodents reported to the CDC.
What to Do After Potential Exposure
Should a potential rabies exposure occur, immediately and thoroughly wash any bite or scratch wound with soap and water for a minimum of 15 minutes. This cleansing action helps to mechanically reduce any viral particles at the wound site.
After wound care, contact a healthcare provider and local public health authorities as soon as possible. These officials will assess the risk based on the animal involved, its behavior, and local rabies prevalence, then guide individuals on whether post-exposure prophylaxis (PEP) is necessary. This medical intervention, which may include a series of vaccinations and immune globulin, is highly effective in preventing rabies if administered promptly after exposure.