The deaths in February of legendary Hollywood actor Gene Hackman and his wife Betsy Arakawa in their home in New Mexico have put a spotlight on hantavirus, a family of viruses that rodents can carry.

Arakawa, 65, died sometime around Feb. 11 of hantavirus pulmonary syndrome, according to Dr. Heather Jarrell, New Mexico’s chief medical investigator.

Hackman, 95, who suffered from Alzheimer’s and cardiovascular disease, is believed to have died on Feb. 18 at the couple’s home near Santa Fe. The couple’s bodies were discovered on Feb. 26, along with their dogs, one of whom was in a crate and died.

The virus particles that spread hantavirus from mouse droppings can float in the air or become aerosolized, and then people can breathe it and can become infected, according to Dr. Michelle Barron, UCHealth senior medical director for infection control and prevention. Barron said hantavirus does not spread from person to person.

“It’s purely a function of inhaling the virus from droppings,” said Barron, a professor of medicine and infectious diseases at the University of Colorado School of Medicine. “People are sweeping or cleaning without the windows open.”

Baron recommends that people air out spaces before cleaning them and should always wear masks while working.

Hantavirus is especially dangerous throughout rural areas of Colorado and the Southwest. According to data from the U.S. Centers for Disease Control and Prevention, Colorado has logged the second highest number of cases of hantavirus in the U.S. since the centers started tracking cases in 1993. From 1993 through 2022, CDC officials logged 119 hantavirus cases in Colorado.

Of the 119 people in Colorado who contracted the illness during that time period, 44 died. Only New Mexico has recorded a higher number of confirmed hantavirus cases. New Mexico health officials documented 122 hantavirus cases from 1993 to 2022, and 52 of those people infected died.

Colorado recorded two cases of hantavirus in 2023 and five cases in 2024 when two of those infected people died, according to Kristina Iodice of the Colorado Department of Public Health and Environment.

Lauren Bryan, an infection preventionist at UCHealth Yampa Valley Medical Center, said people should always be careful when cleaning areas in homes or out buildings that could have mouse droppings.

In Colorado and the Southwest, the strain of hantavirus is “Sin nombre” (Spanish for “no name”) and is carried by deer mice.

“It’s important here in Colorado because we have a fair amount of deer mice,” Bryan said.

The peak season for hantavirus is spring and early summer.

“That’s when people are starting to go in and clear out their sheds and garages where deer mice have been nesting,” Bryan said. “The bodily fluids from the mice carry the virus. So, if people sweep up excrement or touch dead mice or get bitten, they may be exposed.”

Most people who get hantavirus do not see mice. So, experts say it is best to take precautions any time people are cleaning up droppings.

“You may see nesting materials, such as straw or excrement,” Bryan said. “Or the mice may chew stuff up and make holes in dog food bags and other food containers.”

A deer mouse is distinguishable by its two-toned fur with a darker back and white belly, large eyes and a bicolor or half-brown and half-white tail. That contrasts with the house mouse, which has a uniform brown or gray coat and a hairy tail.

On average, symptoms of hantavirus start two weeks after exposure but can hit anytime between one and six weeks. Fever and chills are possible, but people infected have severe leg, hip and back pain.

“You may not get the other symptoms, but you will have leg or hip or back pain that doesn’t go away with ibuprofen or Tylenol,” Bryan said.

The virus can progress quickly, causing inflammation in the heart and lungs, which may result in fluid building up in the lungs and possible death.

Experts say anyone experiencing symptoms of hantavirus should seek medical attention immediately. Hantavirus has no vaccine or cure, but various treatments such as blood pressure support can help counteract the effects of the symptoms. A simple blood test can show the presence of hantavirus.

“Ultraviolet light actually kills the virus,” Bryan said. “Open up and air out the spaces you’re trying to clean and let the sunlight in before you go in and do anything.”

Experts advise preventing mice from nesting in the first place by caulking and rodent-proofing homes and buildings and by trapping mice that have already gotten inside.

“Handwashing is important too, as some transmission happens when people clean up, and then touch their mouth, nose or food,” Bryan said.

Experts say efforts to keep mice out of the house pay off in other ways because mice also carry ticks, which can spread diseases such as Colorado Tick Fever and Rocky Mountain Spotted Fever.