A rare and often deadly virus has killed a third person in the California mountain town of Mammoth Lakes, health officials confirmed Thursday, intensifying concerns after the same illness was linked to the February death of actor Gene Hackman's wife, Betsy Arakawa.
The virus, known as hantavirus, is spread by contact with infected rodent urine, droppings or saliva. All three fatalities this year in Mono County were attributed to hantavirus pulmonary syndrome, a severe respiratory illness with a mortality rate approaching 40%, according to the Centers for Disease Control and Prevention.
"We don't have a clear sense of where this young adult may have contracted the virus," Dr. Tom Boo, public health officer for Mono County, said in a statement. "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."
Hantavirus infections typically stem from activities that stir up dust contaminated with rodent waste-such as cleaning cabins or sheds-but none of the three victims are believed to have engaged in high-risk behaviors. "These folks may have been exposed during normal daily activities, either in the home or the workplace," Boo said.
The virus, which is not transmissible between people, can be inhaled when microscopic particles of contaminated dust become airborne. In one of the fatal cases this year, Mono County Health & Human Services noted the individual had vacuumed an area later found to contain mouse droppings, which may have aerosolized the virus.
Officials suspect that deer mouse populations-common carriers of hantavirus-are elevated this season in Mono County, increasing the risk of incidental exposure. Boo warned that "an increase in indoor mice elevates the risk of Hantavirus exposure," and advised residents to seal gaps larger than a pencil width, use snap traps, and disinfect rodent-contaminated surfaces with bleach solutions.
The current fatalities mark the county's first hantavirus cases since 2019. Between 1993 and 2022, only 27 cases were reported in Mono County. The CDC, which began tracking hantavirus after a 1993 outbreak in the Four Corners region, says most U.S. cases occur in the western states. California recorded 78 cases between 1993 and 2022.
The death of Betsy Arakawa at her Santa Fe home was officially attributed to hantavirus pulmonary syndrome. Gene Hackman, 95, died a few days later of hypertensive and atherosclerotic cardiovascular disease with Alzheimer's as a contributing factor. Authorities found the couple's dog, Zinna, dead from starvation and dehydration.
Dr. Sonja Bartolome of UT Southwestern Medical Center in Dallas emphasized that hantavirus can initially mimic flu-like symptoms. "It really starts like the flu: body aches, feeling poorly overall," she said. "Early in the illness, you really may not be able to tell the difference between hantavirus and having the flu."
Because early symptoms can escalate quickly into respiratory distress, health officials urge prompt medical attention if hantavirus is suspected. There is no specific antiviral treatment, but early supportive care can improve outcomes.
