What to know about the virus

Three individuals in Mammoth Lakes recently succumbed to hantavirus, the same infection that claimed the life of Betsy Arakawa, wife of Gene Hackman, earlier this year. These cases have raised concerns among public health officials about the spread of this rare but deadly disease that primarily affects the lungs.

During a news conference last month, Dr. Heather Jarrell, chief medical examiner at the New Mexico medical investigator’s office, stated that the mortality rate among those infected in the American Southwest ranges from 38% to 50%. The disease gained attention after the chief medical examiner of New Mexico confirmed the cause of death for Arakawa, 65, as hantavirus pulmonary syndrome in March.

The virus is primarily spread through the urine, feces, or saliva of wild rodents, particularly deer mice, common in many parts of California as per the California Department of Public Health.

All three individuals who contracted and died from the virus in Mammoth Lakes exhibited symptoms starting in February. Only one of them had a significant number of mice in their home, according to health officials, but evidence of mice was found in the workplaces of all three.

Dr. Tom Boo, a public health officer for Mono County, where Mammoth Lakes is located, stated, “We believe that deer mouse populations are high this year in Mammoth, and possibly elsewhere in the Eastern Sierra. An increase in indoor mice poses a higher risk of hantavirus exposure.”

Mono County has reported 27 cases of hantavirus since 1993, the highest number in any county in California.

While hantavirus is rare in Los Angeles County, most cases are linked to exposure outside the county. The last reported hantavirus-related death in Los Angeles County was in 2006.

Although rodents are more commonly found in rural and semi-urban areas, any location where rodents establish a presence can pose a risk for infectious diseases, whether in urban or rural settings. Structures such as sheds, cabins, storage facilities, campgrounds, and construction sites that are infrequently used are particularly susceptible to rodent infestation.

How can you protect yourself against hantavirus?

Hantavirus cases can occur throughout the year, but the peak seasons for reported cases in the United States are spring and early summer, coinciding with the reproductive seasons of deer mice.

To reduce the risk of infection, avoid contact with rodents, their droppings, and nesting materials.

Take measures to prevent wild rodents from entering your home, workplace, cabin, shed, car, camper, or any enclosed space. Public health officials recommend the following:

• Seal holes and openings where rodents can enter (the width of a pencil or larger).
• Use snap traps to catch rodents (avoid glue traps or live traps as they can startle the rodents, leading to increased exposure to any viruses they may carry).
• Store all food items in rodent-proof containers.

If you discover evidence of mice in your living or work area, set up snap traps and clean up their waste.

If cleaning is necessary, local and state officials provide the following guidance to protect against exposure:

Before cleaning:

• Ventilate the space you plan to clean for 30 minutes.
• Wear rubber or plastic gloves, an N-95 mask, and use a disinfectant or a bleach-water mixture.

While cleaning (with gloves on):

• Spray the contaminated areas with the disinfectant and let it sit for at least five minutes.
• Avoid sweeping or vacuuming, as it can disperse droppings or infectious materials into the air.
• Use paper towels, a sponge, or a mop for cleaning. Dispose of all cleaning materials in a bag and discard in the trash.

What to expect if you contract hantavirus

Symptoms of hantavirus are similar to other respiratory infections, including fever, headache, muscle aches, and difficulty breathing. Some individuals may also experience nausea, stomach pain, vomiting, and diarrhea.

Symptoms typically appear weeks after inhaling air contaminated with infected deer mice materials.

Complications of hantavirus pulmonary syndrome can lead to lung tissue damage, fluid accumulation in the lungs, and affect heart function. Severe cases may result in heart failure to deliver oxygen to the body. Warning signs include cough, breathing difficulties, low blood pressure, and irregular heart rate.

How is hantavirus pulmonary syndrome treated?

There is no specific treatment or cure for hantavirus, according to the American Lung Association. However, prompt medical care can improve survival chances.

Early detection of the virus and receiving medical attention in an intensive care unit can lead to a better prognosis. ICU treatment may involve intubation, oxygen therapy, fluid replacement, and medications to lower blood pressure.

2025 Los Angeles Times. Distributed by Tribune Content Agency, LLC.