Hantavirus caused three recent deaths in California. Here’s what to know about the virus

Three people in Mammoth Lakes died recently after contracting hantavirus, the same infection that killed Gene Hackman’s wife Betsy Arakawa earlier this year. The cases have heightened concerns among public health officials about the spread of the rare, but deadly disease that attacks the lungs.

At a news conference last month, Dr. Heather Jarrell, chief medical examiner at the New Mexico medical investigator’s office, said that the mortality rate is between 38% and 50% among those infected in the American Southwest. It wasn’t on many people’s radar until New Mexico’s chief medical examiner confirmed Arakawa, 65, died from hantavirus pulmonary syndrome in March.

The virus can spread through the urine, feces or saliva of wild rodents, including deer mice, which are common in many parts of California, according to the California Department of Public Health.

All three individuals who contracted and died from the virus in Mammoth Lakes experienced symptoms beginning in February. Of the three, only one had numerous mice in their home, according to health officials — however, there was evidence of mice in the places where all three had worked.

That “is not unusual for indoor spaces this time of year in Mammoth Lakes,” said Dr. Tom Boo, a public health officer for Mono County, home to Mammoth Lakes.

“We believe that deer mouse numbers are high this year in Mammoth, and probably elsewhere in the Eastern Sierra,” he said. “An increase in indoor mice elevates the risk of hantavirus exposure.”

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

Has hantavirus been detected in Los Angeles County before?

Hantavirus is rare in Los Angeles County, and most cases have been linked to out-of-county exposure. Los Angeles County’s last reported hantavirus-related death was in 2006.

Even though rodents are more likely to be found in rural and semi-urban areas, any area or structure that the animals take up as a home can be a concern when it comes to infectious disease, whether it’s in a city or out in the country. Infrequently used buildings such as sheds, cabins, storage facilities, campgrounds and construction sites are particularly at risk for rodent infestation.

How can you protect yourself against hantavirus?

Hantavirus cases can occur year-round, but the peak seasons for reported cases in the United States are spring and early summer — which coincide with the reproductive seasons for deer mice.

To limit the risk of infection, avoid rodents, their droppings and nesting materials.

In addition, do what you can to keep wild rodents out of your home, workplace, cabin, shed, car, camper, or other closed space.

To do so, Los Angeles County public health officials suggest:

• Sealing up holes (the width of a pencil or larger) and other openings where rodents like mice can get in.
• Place snap traps to catch any rodents (The CDC cautions against using glue traps or live traps because they can scare the rodents, causing them to urinate, which increases your chance of exposure to any virus they may be carrying.)
• Store all food items in rodent-proof containers .

If you discover evidence of mice in your home or workplace, set up snap traps and clean up their waste.

If that occurs, local and state officials offer the following guidance on how to clean up while protecting yourself against exposure:

Before you clean:

• Air out the space you will be cleaning for 30 minutes.
• Get rubber or plastic gloves, an N-95 mask and a disinfectant or a mixture of bleach and water.

While cleaning (with gloves on):

• Spray the contaminated areas with your disinfectant and let it soak for at least 5 minutes.
• Do not sweep or vacuum the area — that could stir up droppings or other infectious materials into the air.
• Use paper towels, a sponge, or a mop to clean. Put all cleaning materials into a bag and toss it in your trash bin.

What to expect if you do contract the hantavirus

Symptoms are similar to other respiratory infections, which include fever, headache, muscle aches and difficulty breathing. Some people also experience nausea, stomach pain, vomiting and diarrhea.

The symptoms usually develop weeks after breathing in air contaminated by infected deer mice.

Complications of hantavirus pulmonary syndrome can lead to damaged lung tissues and fluid buildup in the lungs, according to the Mayo Clinic. It can also affect heart function; severe cases may result in failure of the heart to deliver oxygen to the body. The signs to look out for include cough, difficulty breathing, low blood pressure and irregular heart rate.

What can you do to treat hantavirus pulmonary syndrome?

There isn’t specific treatment or a cure for the disease, according to the American Lung Assn. However, early medical care can increase the chances of survival.

If the virus is detected early and the infected person receives medical attention in an intensive care unit, the ALA said, there is a chance the person will improve.

The ICU treatment may include intubation and oxygen therapy, fluid replacement and use of medications to lower blood pressure.

If your symptoms become severe call your healthcare provider.