The presence of the common house mouse near human dwellings is a significant public health concern because these rodents are known vectors for numerous human pathogens. Their habit of infiltrating homes, garages, and food storage areas places them in close proximity to people. These small pests actively shed viruses and bacteria through their urine, droppings, and saliva, which can contaminate the environment.
Specific Viral and Bacterial Pathogens
One of the most dangerous viruses directly associated with the house mouse is Lymphocytic Choriomeningitis Virus (LCMV), which causes Lymphocytic Choriomeningitis (LCM). This viral infection primarily targets the central nervous system, leading to aseptic meningitis or encephalitis. An estimated five percent of house mice in the United States carry LCMV, and these rodents shed the virus for their entire lifespan without showing symptoms. While many healthy individuals experience only mild, flu-like symptoms, the infection is hazardous for pregnant women, as transmission to the fetus can result in severe birth defects or miscarriage.
House mice are a common source of the bacterial pathogen Salmonella, which causes Salmonellosis. This bacteria resides in the mouse’s intestinal tract and is shed continuously through its droppings, contaminating any surface the mouse touches. In humans, Salmonellosis causes fever, abdominal cramps, and diarrhea. The illness is concerning for young children, the elderly, and those with weakened immune systems, where it can progress to more serious systemic infections.
While the most severe North American hantavirus strain is primarily carried by the deer mouse, the house mouse’s waste still poses a risk from other pathogens. The risk of breathing in aerosolized particles from any rodent droppings is a major concern for viral transmission. Different strains of hantaviruses, like the Seoul virus, are carried by various urban rodents globally, highlighting the danger presented by rodent infestations.
Routes of Human Infection
The primary mechanism for contracting viral diseases from mouse waste is through aerosolization. When dried mouse urine, droppings, or saliva are disturbed—for example, by sweeping or vacuuming—tiny particles containing the pathogens become suspended in the air. Inhaling this contaminated dust is the most common way humans contract viruses like LCMV. This is relevant in enclosed or poorly ventilated spaces like attics, basements, or sheds where mouse activity has been undisturbed.
Indirect contamination of food and surfaces is the main pathway for bacterial transmission. A mouse that walks across a food preparation area, pantry shelf, or kitchen counter leaves behind microscopic fecal matter and urine. When a person subsequently handles contaminated food or touches an infected surface before touching their mouth, the bacteria, such as Salmonella, is ingested. This indirect fecal-oral route is a constant threat in any area accessible to mice.
Direct contact with the rodents themselves or their nesting material is a risk. An infected mouse can transmit pathogens through a bite or scratch, or by direct contact with broken skin. The virus or bacteria can enter the body if a person touches contaminated material and then rubs their eyes, nose, or mouth.
Safe Handling and Cleanup Protocols
Before beginning cleanup of an area contaminated by mice, allow the space to ventilate. Opening windows and doors for at least 30 minutes clears out any airborne particles that may have already become aerosolized. The ventilation reduces the concentration of potentially infectious dust, making the initial entry safer.
Personal protective equipment (PPE) is necessary to prevent direct exposure to pathogens and contaminated materials. This includes wearing non-porous rubber, latex, or vinyl gloves. A face mask, preferably an N95 respirator, should be worn to protect against the inhalation of infectious aerosols.
Never sweep or vacuum dry droppings or nesting materials, as this action launches pathogens into the air. Instead, the waste must be soaked thoroughly with an EPA-registered disinfectant or a bleach solution before removal. The recommended solution ratio is one part household bleach mixed with nine to ten parts water. The materials should be allowed to soak for at least five minutes to inactivate any viruses.
Once the contaminated material has been saturated and disinfected, wipe it up using paper towels or a disposable cloth. All waste, including droppings and nesting material, must be placed into a heavy-duty plastic bag. This bag should be double-bagged and securely sealed before disposal in a covered outdoor trash container.