Health Risks of Rodent Infestations in Missouri

Rodent infestations are more than an unpleasant nuisance — mice and rats in a home pose genuine health and safety risks that justify prompt, effective treatment. Understanding these risks helps homeowners prioritize rodent control and take appropriate precautions when dealing with an active infestation.

Disease Transmission

Rodents are associated with a range of diseases transmissible to humans. In central Missouri, the most relevant include:

Salmonellosis

Mice and rats contaminate food and food preparation surfaces with their droppings, urine, and fur as they travel through kitchens and pantries. Salmonella bacteria present in rodent feces can cause food poisoning with symptoms including diarrhea, fever, and abdominal cramps. Any food that may have been contacted by rodents should be discarded.

Leptospirosis

Caused by bacteria shed in rodent urine, leptospirosis can be contracted through contact with contaminated water or surfaces, or through skin abrasions. Symptoms range from mild flu-like illness to severe disease affecting the liver and kidneys. It is more commonly associated with rat infestations than mice.

Hantavirus

Hantavirus pulmonary syndrome (HPS) is a serious respiratory disease transmitted primarily through contact with deer mouse droppings, urine, or nesting material, or through breathing dust contaminated with these materials. Missouri has documented hantavirus cases, particularly in rural areas. The deer mouse (Peromyscus maniculatus) is the primary carrier. See our dedicated article on hantavirus in Missouri for full detail on precautions.

Lymphocytic Choriomeningitis (LCM)

LCM is a viral infection carried primarily by house mice, transmitted through contact with rodent droppings, urine, saliva, or nesting material. Most infections cause mild flu-like illness, but it can be serious in immunocompromised individuals and poses risks to pregnant women and their unborn children.

Allergens and Asthma

Rodent dander, urine proteins, and fecal matter are potent allergens. In homes with established rodent infestations, mouse allergen accumulates in settled dust throughout the living areas. Mouse allergen is a documented trigger for asthma, particularly in children, and is a significant indoor allergen in homes with rodent activity. The allergen persists in the environment and in settled dust long after an infestation is eliminated.

Food Contamination

Rodents consume and contaminate far more food than they eat outright. A single mouse produces 50 to 75 droppings per day and contaminates food through droppings, urine marking, and fur contact. Any food in packaging that shows signs of gnawing or in locations accessible to rodents should be discarded. Store pantry items in sealed hard-sided containers.

Property Damage and Fire Hazard

Rodents gnaw constantly — their incisors grow throughout their lives and must be worn down. The most serious property damage consequence is gnawed electrical wiring. Damaged wiring insulation can cause shorts that arc and ignite nearby insulation or building materials. Rodent-gnawed wiring is estimated to be a factor in a significant percentage of residential fires of undetermined cause annually. This risk alone justifies treating rodent infestations promptly.

Additional damage includes gnawed water pipes (causing leaks), gnawed structural wood, and destroyed insulation used for nesting.

Safe Cleanup of Rodent Contamination

When cleaning up after a rodent infestation, standard precautions reduce your exposure risk:

• Ventilate the area before cleaning — open windows and doors for 30 minutes before beginning
• Wear rubber, latex, or vinyl gloves
• Do not sweep or vacuum dry rodent droppings — this aerosolizes particles. Instead, spray with disinfectant, let soak for 5 minutes, then wipe up with paper towels
• Dispose of contaminated material in sealed plastic bags
• Wash hands thoroughly after cleanup
• For large contaminated areas (attics, crawlspaces with extensive infestation), professional remediation with appropriate respiratory protection is recommended