Betsy Arakawa Hackman, 65, was found to have a deadly virus carried by rodents.

The causes of death have been revealed for actor Gene Hackman, 95, and his wife Betsy Arakawa Hackman, 65.

Hackman was found to have atherosclerotic cardiovascular disease along with advanced Alzheimer’s disease, while his wife likely passed away first from “hantavirus pulmonary syndrome” (HPS), according to New Mexico authorities.

Hantaviruses include a group of viruses primarily carried by rodents that can cause severe respiratory or renal diseases in humans, according to Dr. Rhys Parry, a molecular virologist at the University of Queensland in Australia.

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Most hantaviruses that are found in North, Central and South America can cause HPS, the condition that Hackman’s wife was found to have, according to the Centers for Disease Control and Prevention (CDC).

“The hantaviruses that are found throughout the United States are not known to spread between people,” the CDC stated.

Gene Hackman and Betsy Arakawa smiling

HPS has a nearly 40% fatality rate in those who are infected, according to the above source.

How hantavirus spreads

“Hantaviruses typically spread when humans breathe in virus particles from disturbed rodent urine, droppings or nesting materials,” Parry told Fox News Digital.

The CDC lists the following potential mechanisms of spread:

• Breathing in contaminated air when cleaning up after rodents
• Touching contaminated objects and then touching the nose or mouth
• Getting bitten or scratched by an infected rodent
• Eating food contaminated with the virus

Dr. Marc Siegel, clinical professor of medicine at NYU Langone Health and Fox News senior medical analyst, agreed that hantavirus can spread via dust from rodents’ saliva, urine and places they touch.

The most common type of rodent to carry it in the U.S. is the deer mouse, the doctor noted.

Early symptoms of hantavirus include fever, muscle aches, fatigue and gastrointestinal issues.

Most hantavirus cases are seen in rural areas, where it is more likely for rodents to get into homes or barns, the CDC noted.

Hantavirus infections are “incredibly rare,” both experts agreed.

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“This is a pretty sad set of circumstances,” Parry noted. “I’m honestly impressed they were able to determine it was HPS after the fact.”

Siegel added that it rarely affects humans “because only some of the rodents have it, and they don’t all come into contact — but one-third to one-half of cases are fatal.”

Symptoms and treatment

Early symptoms of hantavirus include fever, muscle aches, fatigue and gastrointestinal issues that appear anywhere from one to eight weeks after exposure, according to Parry.

“These progress to serious respiratory symptoms like coughing, shortness of breath and fluid in the lungs four to 10 days later,” he said.

Sin Nombre virus is the most common hantavirus in the United States, which causes hantavirus pulmonary syndrome with a mortality rate of approximately 38%.

“It typically becomes fatal when the lungs fill with fluid, leading to respiratory failure and insufficient oxygen reaching vital organs,” Parry noted.

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There is no specific antiviral treatment for hantavirus, the expert said, although early intensive care with oxygen therapy and supportive measures is crucial.

“Early intensive medical care is critical because patients who have sudden acute disease can rapidly become severely sick and die,” the CDC states.

“If a patient is experiencing full distress, it is less likely the treatment will be effective.”

Supportive care can include monitoring heart function, administering fluids and oxygen, and placing the patient on a ventilator as needed. Patients may also receive broad-spectrum antibiotic therapy, fever reducers and pain relievers.

“Even with medical care, 30% to 40% of people who develop hantavirus pulmonary syndrome will not survive.”

“Although there is no cure for hantavirus pulmonary syndrome, it is important to seek medical care when short of breath, because the patient may need support from a mechanical ventilator or extra-corporal membrane oxygenator (ECMO) machine to deliver enough oxygen to their body,” Dr. Sonja Bartolome, an expert in pulmonology and critical care at UT Southwestern Medical Center, told Fox News Digital.

“Even with medical care, 30% to 40% of people who develop hantavirus pulmonary syndrome will not survive.”

Prevention of hantavirus

Bartolome offered some tips for preventing this rare infection.

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“It can be prevented by keeping wild mice and rats out of your home, cleaning up rodent waste quickly when encountered, and staying away from areas infested with rodents,” she told Fox News Digital.

“When cleaning up rodent waste, it is important to wear rubber gloves, use disinfectant and wash your hands afterward.”

Melissa Rudy is senior health editor and a member of the lifestyle team at Fox News Digital. Story tips can be sent to [email protected].