Mono County Issues Hantavirus Warning

May 14, 2020 – As the weather is warming and people are spring cleaning, Mono County Health Department would like to remind residents of the risk of hantavirus in the Eastern Sierra, a known region of exposure in the United States.

People may catch hantavirus by inhaling virus that is found in the urine, feces, saliva, and nesting materials of infected deer mice. Most people who become ill with hantavirus report some exposure to rodents in the preceding weeks, typically while cleaning enclosed spaces that have been closed-up for some time with mice living there.

For more information on hantavirus, click here.

Hantavirus illness begins with a fever and flu-like symptoms, such as headache and body aches, typically one to five weeks after inhaling the virus. Gastrointestinal symptoms such as vomiting, diarrhea and abdominal pain are common in the early part of the illness. Respiratory symptoms, including cough and feeling short of breath, may develop after a few days, signaling increased chance of deadly respiratory and heart failure. When people start having trouble breathing, their condition may rapidly worsen and become critical. There is no specific treatment for hantavirus infection, but high-level intensive care has allowed many people with life-threatening illness to survive. Overall, approximately 25-33% people with hantavirus infection die.

It is important to note key similarities and differences between hantavirus infection and COVID-19. For one, COVID-19 is spread from person to person, whereas hantavirus is spread from deer mouse waste. A person with hantavirus cannot spread it to another person. Both infections may present with flu like symptoms such as fever, fatigue, cough, shortness of breath, or muscle pains. This is why it is critical for residents to be aware of and avoid exposure to rodents, their waste, and their nesting materials. If you begin experiencing any of these symptoms, you should call your primary healthcare provider or the Mono County Nurse Hotline at 211. Be sure to inform health professionals of any exposures you may have had to both mouse waste and COVID-19. Timely hantavirus and COVID-19 diagnosis and potential transfer to higher level hospital care is crucial as these diseases can progress rapidly.

To decrease risk of hantavirus infection:

• Open windows and doors of a potentially contaminated area and allow it to air out for at least 30 minutes before cleaning. Cross-ventilation is best.

• Avoid sweeping, vacuuming or other activities that stir up dust and dirt that may contain the virus.

• Spray dead rodents, nests, droppings, and other potentially contaminated items and surfaces with a 10% bleach solution (1 part bleach with 10 parts water) or a disinfectant made to kill viruses (check the label). A dead mouse caught in a trap should not be removed from the trap. Instead, the trap and mouse together should be disinfected, bagged and discarded into the trash.

• Wait at least 5 minutes after spraying the disinfectant on things before wiping.

• Inspect vehicles for rodents. Mice incursion in vehicles may also pose some hantavirus risk, especially if mice infest the heating and air conditioning system.

• Minimize mouse entry points at home and at work. Mice may enter through very small gaps under doors or around windows and where conduits and vents pass through walls. Heating and air conditions ducts should be periodically inspected for holes and/or rodent feces or nesting material.