Hantavirus awareness: deer mice vs. house mice

I was asked, “Do house mice carry hantavirus?” Looking it up on the Centers For Disease Control and Prevention (www.cdc.gov/hantavirus/index.html) it seems that deer mice carry hantavirus in our area. House mice, roof rats, Norway rats or ground squirrels are not known to transmit hantavirus pulmonary syndrome (HPS) to people. Dogs and cats do not transmit the disease.

The deer mouse ranges from grey to reddish brown, depending on age. The underbelly is always white and the tail has clearly defined white sides.

People get HPS when they breath in hantavirus after stirring up rodent urine, droppings or nesting materials that contain the virus. They can also get it if they touch these things. Disease particles can become airborne when you clean a shed, garage, barn or other building where mice live that has been closed for some time. Sometimes hikers and backpackers encounter disease in old cabins and barns.

The disease is not transferable person to person. Symptoms begin within one to five weeks after being around mice that carry the virus. They include fever, severe muscle aches and fatigue. After a few days, it can become difficult to breathe. Headaches, dizziness, chills, nausea, vomiting, diarrhea and stomach pain can occur. Heart and lung failure can be fatal. Early intervention is critical.

To clean out a building first open all doors and windows for at least 30 minutes before entry. Before you clean up rodent urine, droppings or nesting materials, put on rubber or plastic gloves and a face mask and spray with a disinfectant or a mixture of bleach and water (1½ cups of household bleach with 1 gallon of water or 1 part bleach to 9 parts water). Thoroughly wet the materials and let the disinfectant soak in for five minutes before disturbing. Wipe up the materials with disposable towels and throw them away in an outside trash can. Then mop or sponge the floor with more disinfectant or bleach mix. Wash your gloved hands with soap and water or a disinfectant before taking off the gloves. Wash your bare hands with soap and water after taking off your gloves.

Do not sweep or vacuum up the urine, droppings or nests because this causes the virus particles to go into the air from where they can be breathed. While hantavirus is rare, it is wise to take precautions when dealing with rodent urine, droppings or nesting material.

JoAnne Skelly is associate professor and Extension educator, Emerita at University of Nevada Cooperative Extension. She can be reached at skellyj@unce.unr.edu.