Expert Explains The Deadly Virus Behind Hollywood Tragedy

Oscar-winning actor Gene Hackman and his wife Betsy Arakawa were found dead, along with their pet dog, at their home in Santa Fe, New Mexico in February 2025, sparking intense online speculation about the cause of death.

In March, New Mexico's chief medical examiner, Dr Heather Jerrell, announced that Hackman, who was in the advanced stages of Alzheimer's disease, died from hypertensive and atherosclerotic cardiovascular disease – a combination of high blood pressure and a buildup of plaque in the arteries.

Arakawa, however, died around a week before her husband from hantavirus pulmonary syndrome – an infection transmitted to humans from rodent faeces, urine and saliva.

It's unknown how Arakawa contracted hantavirus. Usually, farmers and forestry workers are most at risk of exposure to infected rodents.

There are at least 38 recognised species of hantavirus across the world, 24 of which cause disease in humans. It's considered a rare virus but it's also likely to be underdiagnosed in many areas of the world because the initial symptoms can be mistaken for cold and flu-like viral infections.

Hantaviruses are typically divided into "old-world" and "new-world" types. Old world hantaviruses are found in Europe and Asia, including the puumala hantavirus, which uses the bank vole as its host, and the Hantaan virus and Seoul virus, carried by the striped field mouse and the common brown rat.

These hantaviruses cause haemorrhagic fever with renal syndrome (HFRS) – bleeding from various areas of the body and varying degrees of kidney impairment.

Estimated to affect 150,000 people annually, this condition is usually reversible. Some patients may develop nephropathia epidemica – a milder form of the virus.

New world hantaviruses, found in North and South America, result in hantavirus pulmonary syndrome (HPS), which tends to be more severe than HFRS. It affects the lungs and heart, impairing the delivery of oxygen around the body.

In North America, the most common type of hantavirus is the sin nombre virus spread by the deer mouse. In South America the andes virus, often carried by the long-tailed pygmy rice rat, is most common.

Hantavirus transmission

The disease is caused by inhaling rodent faeces, urine or saliva – often from disturbing rodent nests and droppings while cleaning. More rarely, hantavirus is transmitted by bites and scratches from infected animals.

A small number of studies have documented human-to-human spread of the andes strain in South America, but a systematic review of the research didn't find enough evidence of human-to-human transmission.

The incubation period of hantavirus is relatively long, typically two to three weeks, but can be as long as six weeks. This may be why cases are underreported – patients may forget the potential exposure event. Diagnosis is usually based on symptoms and history, although laboratory tests can detect antibodies to hantavirus in human serum.

The virus causes a change in the permeability of the cells that line blood vessels so that fluid leaks out in places it shouldn't, such as the lungs and kidneys. It also reduces the number of platelets in the blood, reducing blood clotting so that blood leaks from organs and vessels.

The hantavirus also appears to prevent apoptosis – when the body kills cells in response viral infection – so the body is unable to get rid of infected cells as efficiently, which prolongs the virus.

The severity of the virus depends on a number of factors, including age and genetic predisposition. People over the age of 70 are most likely to die of hantavirus, while some human leukocyte antigens– the immune system markers that check which cells belong in your body and which do not – show an increased risk of severe disease.

It isn't known how long immunity following hantavirus infection lasts, but immunoglobulin G antibodies – a type of protein that helps the body fight infections from viruses and bacteria – are likely to protect against subsequent symptomatic infection from the same strain.

However, given the large number of hantavirus species, having had one form would be unlikely to protect against catching a different form.

Symptoms

Infection with either old or new world strains start with similar viral symptoms: fever, headache, fatigue, muscle pains, abdominal issues including nausea, vomiting, diarrhoea and abdominal pains. The old and new strains have different disease progression. Both strains should be treated promptly to reduce risk of death.

In old-world infections leading to HFRS, patients move from the generic symptoms to low blood pressure and then reduced urinary output. Patients may need dialysis to protect the kidneys.

Those infected will then experience increased urinary output to clear the excess fluid collected in the previous stage of the disease. Finally, patients enter the convalescent phase with fatigue and muscle pains.

In HPS from new-world hantavirus strains, symptoms usually appear within eight weeks of exposure. Three to five days of generic symptoms are followed by rapid deterioration as fluid fills the lungs making breathing difficult.

Many patients require mechanical ventilation such as extracorporeal membrane oxygenation – a kind of life support where blood is pumped outside of the body to a heart-lung machine. In the final stage of the disease, urine output will increase significantly as the body attempts to expel excess fluid.

With early treatment, most people with HPS fully recover with no lasting effects – but mortality rate can be as high as 40 percent.

Treatments

Treatment is targeted towards symptom management with oxygen therapy. Antiviral medication ribavirin has shown in trials to be more beneficial for HFRS than HPS. A hantavirus vaccine trailed in South Korea generated a good immune response and was well tolerated for prevention of HFRS but wider results are unclear.

As always, prevention is better than cure and the most effective way to prevent hantavirus infection in humans is to keep surroundings free from rodents. But, this is easier said than done – so cleaning with disinfectant is essential to ensure areas are free of rodent fluids and faeces.

Allow disinfectant or bleach to soak the area for at least five minutes before cleaning with absorbent materials. Gloves and a mask, of course, should be worn at all times.

Adam Taylor, Professor of Anatomy, Lancaster University

This article is republished from The Conversation under a Creative Commons license. Read the original article.