Raccoons are highly adaptable mammals common in urban and suburban environments. They are recognized carriers of several pathogens that can be transmitted to humans and pets, known as zoonotic diseases. Understanding the health risks associated with raccoons and their waste is important for public health and safety. This article highlights the viral, parasitic, and bacterial threats raccoons introduce into human-populated areas.
Rabies: The Primary Viral Concern
Rabies is a viral infection that attacks the central nervous system of mammals, including raccoons. It remains the most recognized viral threat from this species. The virus spreads almost exclusively through direct contact with infected saliva, typically via a bite or when saliva enters an open wound or mucous membrane. Once symptoms appear, the disease is nearly always fatal in humans, making immediate medical response critical.
A rabid raccoon may exhibit behavior uncharacteristic of a healthy, nocturnal, and timid animal. Signs of infection include daytime activity, lethargy, staggering, lack of coordination, and unprovoked aggression or unusual tameness. Any physical contact with a raccoon, especially a bite or scratch, requires immediate medical evaluation for post-exposure prophylaxis (PEP). The PEP regimen involves a series of vaccinations and the administration of rabies immune globulin to stop the virus before it reaches the brain.
Raccoon Roundworm: A Specific Parasitic Threat
The parasitic threat uniquely associated with raccoons is Baylisascaris procyonis, commonly known as raccoon roundworm. This parasite resides in the animal’s small intestine. Infected raccoons shed millions of microscopic eggs in their feces, depositing them in communal latrines, often found in attics, chimneys, or on woodpiles. The eggs are not immediately infective but become resilient and capable of causing disease after two to four weeks in the environment.
Infection occurs when a human or pet accidentally ingests these infective eggs through contaminated soil, water, or objects. Once ingested, the eggs hatch into larvae that migrate through the body’s tissues. This migration can lead to severe neurological consequences, a condition called neural larva migrans (NLM), where the larvae invade the brain and central nervous system.
Initial symptoms of Baylisascaris infection may include nausea and fatigue. If the larvae reach the brain, the resulting inflammation can cause loss of coordination, blindness, seizures, and coma. The larvae are also capable of causing ocular larva migrans (OLM) when they migrate to the eyes. Since treatment options are limited once symptoms develop, avoiding environmental contamination from raccoon latrines is the primary method of prevention.
Other Bacterial and Environmental Pathogens
Raccoons are reservoirs for several bacterial diseases that spread through environmental contamination. One such disease is Leptospirosis, a bacterial infection caused by Leptospira species, which is shed in the urine of infected animals. Humans become infected when contaminated water, soil, or surfaces contact broken skin or mucous membranes.
Leptospirosis causes flu-like symptoms, including fever, headache, and muscle aches. In severe cases, it can lead to kidney damage, liver failure, and meningitis. Another risk is Salmonellosis, caused by Salmonella species carried by raccoons in their intestines. Transmission occurs through the fecal-oral route, usually by contact with contaminated feces or surfaces, leading to gastrointestinal symptoms like diarrhea, fever, and abdominal cramps.
Protective Measures and Safe Handling
Minimizing contact with raccoons and their waste is the most effective strategy for disease prevention. Property owners should eliminate attractants by securing garbage containers with tight-fitting, locked lids and removing outdoor pet food and water sources. Sealing potential entry points, such as uncapped chimneys, foundation gaps, and openings to sheds or attics, prevents raccoons from establishing dens near human living spaces.
If a raccoon latrine is discovered, cleanup should be performed with caution using protective gear, including disposable gloves and an N95-rated respirator, especially in confined areas. Feces and contaminated materials should be removed and disposed of by burial, burning, or landfill, as most chemical disinfectants do not reliably kill roundworm eggs. Surfaces like decks or patios can be treated with boiling water or a propane torch, which instantly destroys the eggs. Keeping domestic pets current on their Rabies and Leptospirosis vaccinations provides protection against these common environmental exposures.