Opossums are common in many neighborhoods, often leading to questions about their potential to transmit diseases, especially rabies. While any mammal can contract rabies, it is exceptionally uncommon for opossums to carry and transmit the virus. They are not considered a primary carrier of the disease, unlike other wildlife species.
Opossums and Rabies Risk
The incidence of rabies in opossums is notably low. Health organizations, such as the Centers for Disease Control and Prevention (CDC), report that opossums have one of the lowest rates of rabies positivity among wildlife tested. For instance, a study in Florida found no positive rabies cases in thousands of opossums tested over a 30-year period. The majority of rabies cases in U.S. wildlife are found in bats, raccoons, skunks, and foxes.
Why Opossums Rarely Carry Rabies
Opossums rarely contract rabies due to their unique biology. Their average body temperature, 94-97°F (34-36°C), is lower than most mammals, making it difficult for the rabies virus to survive and replicate. Opossums also possess a robust immune system. Their natural resistance to many viral and bacterial diseases contributes to their ability to fight off infections. This combination provides them with a natural defense against the rabies virus.
Other Health Concerns from Opossums
While rabies is an uncommon concern, opossums can carry other health risks, similar to any wild animal. They host parasites like fleas, ticks, and mites, which can be transferred to pets or humans. These parasites can, in turn, transmit other diseases like Lyme disease or Rocky Mountain spotted fever. Opossums can also be carriers of certain bacteria and pathogens, including Salmonella (food poisoning) and Leptospira (leptospirosis). Additionally, scratches or bites, like any animal bite, can lead to bacterial infections if not properly cleaned.
Responding to Opossum Encounters
If an opossum is present in your yard, it is generally best to leave it undisturbed; they are often just passing through and will move on. Opossums are not typically aggressive and will usually try to avoid confrontation. In the rare event of a bite or scratch, clean the wound immediately and thoroughly with soap and warm water, then apply an antiseptic and cover with a clean bandage. Seeking medical attention is advisable for any animal bite to evaluate the wound and discuss potential treatment, such as antibiotics to prevent infection.