Hantavirus is a family of viruses carried by certain wild rodents, such as the deer mouse in North America. Rodents shed the virus through their urine, droppings, and saliva without becoming ill. Humans become infected by inhaling airborne virus particles in closed, rodent-infested spaces. This exposure can lead to Hantavirus Pulmonary Syndrome (HPS), a severe, sometimes fatal respiratory illness.
The Short Lifespan of Hantavirus Outside the Host
Hantavirus is a fragile, enveloped virus that does not survive long outside of the host. This structure makes it highly susceptible to desiccation and standard disinfectants. Under typical indoor conditions, the virus remains infectious for a short time, often measured in hours or, at most, a few days.
At normal room temperature, Hantavirus can survive for about two to three days on surfaces. Survival may extend up to four days when shielded within bulk material like deep rodent droppings or nesting materials. Environmental factors like ultraviolet (UV) light, high temperatures, and low humidity rapidly degrade the virus. Freezing temperatures can extend the time the virus remains infectious.
Understanding Indoor Aerosol Risk
The primary pathway for human infection is inhaling aerosolized virus particles. The virus is shed in the rodent’s excreta (urine, droppings, and saliva), which dries out and mixes with dust. When this contaminated material is disturbed, the microscopic particles become airborne and are easily breathed into the lungs.
High-risk environments are indoor spaces that have been closed and undisturbed for a long time, allowing rodents to infest the area. This includes unused cabins, sheds, barns, crawl spaces, and attics. The danger arises from disturbing the contaminated material. Activities such as sweeping, vacuuming, or walking through a contaminated area can aerosolize the infectious dust. This aerosolization delivers the virus into the respiratory system, making cleanup the most likely time for exposure.
Essential Steps for Safe Cleanup
Safe cleanup procedures must focus on preventing the aerosolization of particles. Before entering any potentially contaminated area, ventilate the space by opening all doors and windows for at least 30 minutes. This airing-out period helps remove any infectious aerosols that may have accumulated.
Proper personal protective equipment (PPE) is necessary before beginning work. At a minimum, this includes wearing rubber, latex, vinyl, or nitrile gloves. In dusty or confined environments, wearing a well-fitting N95 respirator is recommended to filter airborne particles.
The critical step in neutralizing the virus is using a wet cleaning method to soak the contaminated materials before removal. Never sweep, vacuum, or dry-dust the area, as this stirs up infectious particles. Instead, spray all droppings, urine, nests, and dead rodents thoroughly with a household disinfectant or a bleach solution. A common solution is one part bleach to ten parts water (a 10% hypochlorite solution).
Allow the solution to soak for five to ten minutes to ensure the virus is inactivated. Once the materials are thoroughly wetted, carefully wipe them up with disposable rags or paper towels. All contaminated cleaning materials, including dead rodents, must be double-bagged and disposed of in a sealed garbage can. After cleanup, disinfect the gloves before removal, and then wash hands thoroughly with soap and warm water.