Rodent Infestations and the Spread of Infectious Diseases


Rodents are known to transmit more than 35 illnesses. What signs should environmental services personnel and infection preventionists look for?

A tiny mouse can cause significant issues.

A tiny mouse can cause significant issues.

(Adobe Stock)

While rodents are active year-round, they seek shelter indoors when outdoor temperatures are low. This creates a season of vulnerability in rodent infestation in both businesses and homes. For health care facilities, in addition to impacting business reviews, damaging public perception, and causing extensive property damage, rodents can also spread diseases and jeopardize the health and safety of patients and staff.

Rodents—and the parasites that they can carry with them—can pose significant health risks and are known to transmit more than 35 illnesses. Rodents can both directly and indirectly spread diseases, which means that some diseases can spread directly through a rodent bite. In contrast, others can be passed indirectly through droppings, urine, saliva, blood, or exposure to the fleas and mites they carry.

Frank Meek, BCE, PHE, PCQI

Frank Meek, BCE, PHE, PCQI

(Photo courtesy of author)

It’s important to note the health risks rodents can pose to employees and customers; however, the frequency of rodent-transmitted disease is low compared to the relative volume of these pests. Some of the most common diseases that rodents have been linked to are:

  • Food poisoning (including Salmonella): Spread through rodent feces by contaminating areas where food is handled or stored, ingesting contaminated food can lead to diarrhea, nausea, and other intestinal disorders.
  • Hantavirus:From 1993-1994, an outbreak of Hantavirus resulted in more than 50 deaths in 17 states. This disease is most commonly spread when rodents’ feces, urine, or bodily fluids come into contact with humans.
  • Rat-bite fever: This occurs when bacteria in the mouths and noses of rats and mice are transmitted through biting.
  • Bubonic plague: Perhaps one of the most notorious rodent-borne illnesses, this disease is spread from bites from infected fleas. The Bubonic plague killed more than a third of the human population in 1347, and even today, there are more than 600 annual cases.
  • Hepatitis E: Usually spread through contaminated water, hepatitis E is a liver disease caused by the hepatitis E virus (HEV). Although rare in developed countries, the disease is now linked to rodents.
  • Leptospirosis: Usually caused by exposure to contaminated water, such as floodwater, leptospirosis is also spread through direct contact with urine from infected animals—such as rodents—or through water, soil, or food contaminated with their urine.

Spotting a Rodent Problem

Rodent infestations can be extremely destructive, not just due to the spread of pathogens and deadly diseases but also within your facility. For example, rats use their teeth to gnaw on electrical wiring or structural materials. Therefore, keeping an eye out for them around your business is crucial. And while their presence may manifest in obvious ways, like a mouse scurrying across the floor, rodents can also go undetected until they become a significant pest control challenge. Some subtle clues can reveal an underlying rodent issue, including:

Droppings (feces): Capsule-like pellets around the area should raise a red flag.

Nesting: Rodents build nests made from shredded material like paper, cloth, and cardboard for both personal shelter and food storage. These can usually be found in dark areas like crawlspaces, between walls, and in garbage dumps.

Burrows: These pests can create elaborate underground tunnels or simple excavated holes in roofs and underneath buildings, walls, and green-scaped areas.

Grease marks: Oil and dirt in rodent fur leave behind grease marks as they travel along walls. Darker grease stains generally indicate heavier or longer activity in that area.

Gnaw marks: Since their teeth never stop growing, rodents bite on all kinds of items. Look for chew marks on walls, insulation, wires, flooring, pallets, and products. Also, listen for heavy scratching noises.

Rodents are known to multiply quickly, making infestations challenging to remove.

Sanitation & Disinfection

Proper sanitation practices are the key to avoiding the risk of rodent-borne disease outbreaks. Sanitation and pest control go hand in hand to help create an environment that will make employees, patients, and other visitors feel safe because rodents are attracted to cluttered, dirty spaces. Maintaining a regular and thorough sanitation schedule can help prevent rodents and better recognize any warning signs early. To implement an effective sanitation routine:

  1. Wipe down equipment and machinery to clear moisture buildup or debris.
  2. Use proper storage practices, including keeping containers off the ground and on open-backed shelves.
  3. Ensure employees wash their hands and keep breakrooms free of clutter, food debris, and trash. Remember to clean up any spills or leaks after they occur.
  4. Regularly empty trashcans and garbage around the facility to prevent lingering rodent attractants.
  5. Clean drains in and around your building often to help prevent food debris and other buildup.

Locations around a health care facility to keep a regular eye on include breakrooms, loading docks, landscaping, maintenance rooms, and food service areas.

Rodents are both unsettling to look at and a threat to your facility, but even more, they are a significant hazard to human health. Seeing 1 tiny mouse is terrifying to some—now imagine an infestation. Rodents are known to multiply quickly, making infestations challenging to remove. Work with a trusted pest control provider to address any current rodent concerns and implement solutions around your facility to help prevent future issues and keep your employees and patients safe from the filth and illnesses rodents spread.

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