Betsy Arakawa, the wife of the late Gene Hackman, died of hantavirus pulmonary syndrome, New Mexico officials said Friday.

The confirmation of her cause of death ends weeks of mystery after both Arakawa, 65, and Hackman, 95, were found dead inside their Santa Fe home on Feb. 26, with no obvious signs of how they died, according to the Santa Fe County Sheriff’s Office.

The state’s chief medical investigator said Friday that Hackman, an Academy Award-winning actor, died of hypertensive cardiovascular disease, with “Alzheimer’s disease as a significant contributory factor.”

Officials said that Hackman died around Feb. 18, and Arakawa died around Feb. 11. Hackman, who was known to share three pet dogs with Arakawa, was likely home with his deceased wife for one week before he died, authorities said.

While Hackman’s cause of death — a condition in which high blood pressure damages the blood vessels, leading to heart problems — is more common, the syndrome that caused Arakawa’s death is rare.

There have been fewer than 900 cases of hantavirus pulmonary syndrome in the United States over the past nearly 30 years, according to the U.S. Centers for Disease Control.

What is hantavirus pulmonary syndrome?

Hantavirus pulmonary syndrome is a condition that “causes flu-like symptoms that can progress to more severe illness where people have trouble breathing,” according to the CDC. It is a severe and potentially fatal infection that primarily affects the lungs and needs prompt medical attention.

Hantaviruses are a family of viruses that can cause serious illness and death, and some hantaviruses cause hantavirus pulmonary syndrome.

Most of the hantaviruses found in the U.S. cause hantavirus pulmonary syndrome, according to the CDC.

What are the symptoms of hantavirus pulmonary syndrome?

At its start, hantavirus pulmonary syndrome causes flu-like symptoms that can then progress to more severe illness, causing difficulty breathing, according to the CDC.

Early symptoms can include fever, muscle aches, fatigue. About 10 days into the illness, patients can develop coughing and shortness of breath with some potentially experiencing fluid building up in the lungs.

How is hantavirus pulmonary syndrome treated?

The CDC recommends that patients suspected of having hantavirus pulmonary syndrome be treated promptly, even before a diagnosis is made, as symptoms from hantavirus can resemble many other viral infections, such as influenza.

Hantavirus is diagnosed with a blood test.

Medical care for hantavirus pulmonary syndrome may include supplemental oxygen, antibiotic therapy, fluids and mechanical or non-invasive ventilation, according to the CDC.

The syndrome is fatal in nearly four in 10 people who are infected, according to the CDC.

How is hantavirus spread?

Hantavirus pulmonary syndrome is spread by infected rodents through their urine, feces and saliva, according to the CDC.

In the U.S., the most common hantavirus that causes hantavirus pulmonary syndrome is spread by the deer mouse.

People can become infected if they breathe in hantavirus-contaminated air when cleaning up after rodents; touch contaminated objects and then touch their face; are bitten or scratched by an infected rodent; or eat food that has been contaminated with hantavirus, according to the CDC.

Dogs and cats are not known to be infected by hantavirus, according to the CDC, but they can spread it to humans if they bring infected rodents to people or inside homes.

How common is hantavirus pulmonary syndrome?

There have only been around 860 cases of hantavirus pulmonary syndrome since the CDC started tracking the syndrome in 1993 in the U.S.

The state of New Mexico reported seven cases of hantavirus pulmonary syndrome in each of the past two years.

Between 1975 and 2023, the state recorded a total of 129 hantavirus pulmonary syndrome cases with 52 deaths, according to the New Mexico Department of Health.