(NEXSTAR) A third person in the remote California town of Mammoth Lakes has died of hantavirus, the sometimes-fatal illness that authorities say Betsy Arakawa, the wife of actor Gene Hackman, died of earlier this year.

In a statement shared Thursday, Mono County Health & Human Services confirmed that a young adult had died from the illness.

“We don’t have a clear sense of where this young adult may have contracted the virus,” Dr. Tom Boo, the county’s public health officer said. “The home had no evidence of mouse activity. We observed some mice in the workplace, which is not unusual for indoor spaces this time of year in Mammoth Lakes. We haven’t identified any other activities in the weeks before illness that would have increased this person’s exposure to mice or their droppings.”

Hantavirus, found throughout the world, is spread by contact with rodents or their urine or feces. It does not spread between people. There is no specific treatment or cure, but early medical attention can increase the chance of survival.

An infection can rapidly progress and become life-threatening.

“It really starts like the flu: body aches, feeling poorly overall,” said Dr. Sonja Bartolome of UT Southwestern Medical Center in Dallas. “Early in the illness, you really may not be able to tell the difference between hantavirus and having the flu.”

The virus can cause a severe and sometimes deadly lung infection called hantavirus pulmonary syndrome, according to the CDC. All three deaths in Mono County were connected to this syndrome, which is spread by deer mice, health officials said.

Boo said deer mouse numbers are believed to be high this year in the Mammoth Lakes area, noting that “an increase in indoor mice elevates the risk of Hantavirus exposure.”

Boo noted that of the three deaths reported in the county so far, they do not believe that any of them “engaged in activities typically associated with exposure, such as cleaning out poorly ventilated indoor areas or outbuildings with a lot of mouse waste.”

“Instead, these folks may have been exposed during normal daily activities, either in the home or the workplace.”

According to the press release from Mono County Health & Human Services, all three residents began to feel ill in February. In all three cases, “there was some evidence of mice” in their workplaces “but no major infestations were found,” while one had “numerous mice in their home.”

One person had been vacuuming “in one or more areas where investigators later found mouse droppings,” the department noted, adding that vacuuming “can aerosolize the virus through the air and lead to infection.”

The best way to avoid the germ is to minimize contact with rodents and their droppings. Use protective gloves and a bleach solution for cleaning up rodent droppings.

The CDC began tracking the virus after a 1993 outbreak in the Four Corners region the area where Arizona, Colorado, New Mexico, and Utah meet. Ever since, the majority of U.S. cases have been reported in western states. That includes 78 cases reported in California between 1993 and 2022.

Video below: Authorities provide causes of death for Gene Hackman, Besty Arakawa on March 14, 2025

While hantavirus is not uncommon in Mono County there have been 27 cases reported since 1993 cases are typically seen during late spring or summer, making the three cases reported already this year “strikingly unusual.”

Prior to the cases confirmed this year, Mono County had not seen a hantavirus infection since 2019.

Hantavirus is not spread between people, health officials said. Roughly one-third of people who do become infected die.

Last month, New Mexico authorities confirmed that Arakawa found dead in the home she shared with her husband, Hackman had died from hantavirus pulmonary syndrome. Authorities have not said how Arakawa, 65, may have become infected.

Investigators determined Hackman, 95, died of heart disease with complications of Alzheimer’s days after his wife died. Their dog, Zinna, was found dead of starvation and dehydration.

The Associated Press contributed to this report.