Hantavirus season arrives with spring cleaning

Mice carry the hantavirus all year, but spring marks the start of the season when the risk of exposure rises, according to a press release from the Mono County Health Department.

Buildings that have been closed and unused all winter often provide habitats for deer mice, and when they are opened in the spring for cleaning, human exposure to the hantavirus is possible.

Although hantavirus infections are relatively rare, it is not unusual to have several cases per year in the Eastern Sierra, and the risk of death is significant, according to the release.

Hantavirus is carried by certain species of rats and mice, and especially the deer mouse. Infected rodents shed the virus in their urine, droppings, and saliva. 

If infected urine, saliva, droppings, or nesting materials are disturbed, the virus will be temporarily aerosolized, and this can be transmitted to humans if it is inhaled.

The health department recommends the following precautions:

  • seal openings that may allow mice to enter homes and workplaces
  • remove brush, woodpiles, trash, and other items that may attract mice
  • tightly close garbage cans, pet food containers, and other food sources
  • wear protective gloves to handle dead mice or to clean up nesting areas, urine, or droppings
  • before cleaning up nests or droppings found inside, open windows and doors to ventilate the area for at least 30 minutes
  • do not stir up nests by sweeping or vacuuming; dampen areas before clean-up
  • use a disinfectant or 1-to-10 part bleach-water mixture to clean up dead rodents, nests, urine, and droppings

The health department says, "early symptoms of hantavirus infection include fatigue, fever, and muscle aches. These symptoms may be accompanied by headaches, dizziness, chills, nausea, vomiting, diarrhea, and abdominal pain. Later symptoms include coughing and shortness of breath. If hantavirus is suspected, people should contact their health care provider immediately. Remember, infections with hantavirus may feel like the flu; however, it is no longer flu season."

For more information, including an interactive map showing Mono and Inyo County specific information, go to: