A suspected hantavirus outbreak aboard a cruise ship has claimed three lives and left others ill. The World Health Organization (WHO) stated that detailed investigations are underway, including extensive laboratory testing and epidemiological studies to understand the virus's spread. Sequencing of the virus from the current outbreak is also ongoing.
What is Hantavirus?
Hantaviruses, which have existed for centuries, have a documented history of outbreaks across Asia and Europe. In the Eastern Hemisphere, these viruses are associated with severe conditions such as haemorrhagic fever and kidney failure. A distinct group of hantaviruses emerged in the early 1990s in the southwestern United States, leading to the acute respiratory disease known as hantavirus pulmonary syndrome. The disease gained significant attention in 2025 following the death of Betsy Arakawa, wife of actor Gene Hackman, from a hantavirus infection in New Mexico.
How Hantavirus Spreads
Hantavirus is primarily spread through contact with rodents or their urine, saliva, or droppings, especially when these materials are disturbed and become airborne, posing an inhalation risk. People are typically exposed around homes, cabins, or sheds, particularly when cleaning enclosed spaces with poor ventilation or entering areas with mouse droppings. The WHO notes that while rare, hantaviruses may spread between people.
The US Centers for Disease Control and Prevention began tracking the virus after a 1993 outbreak in the Four Corners region, where Arizona, Colorado, New Mexico, and Utah meet. A doctor with the Indian Health Service first noticed a pattern of deaths among young patients, said Michelle Harkins, a pulmonologist at the University of New Mexico Health Sciences Center who has studied the disease for years. Most US cases occur in Western states, with New Mexico and Arizona being hotspots, likely due to greater odds of mouse-human encounters in rural areas.
Symptoms of Hantavirus
An infection can rapidly progress and become life-threatening. Experts say it can start with symptoms including fever, chills, muscle aches, and possibly a headache. “Early in the illness, you really may not be able to tell the difference between hantavirus and having the flu,” said Dr. Sonja Bartolome of UT Southwestern Medical Center in Dallas.
Symptoms of hantavirus pulmonary syndrome usually appear one to eight weeks after contact with an infected rodent. As the infection progresses, patients may experience chest tightness as the lungs fill with fluid. The other syndrome caused by hantavirus—hemorrhagic fever with renal syndrome—typically develops within one to two weeks after exposure.
Death rates vary by the hantavirus causing the illness. Hantavirus pulmonary syndrome is fatal in nearly 40% of infected people, while the death rate for hemorrhagic fever with renal syndrome ranges from 1% to 15%, according to the CDC.
How to Prevent Hantavirus
There is no specific treatment or cure, but early medical attention can increase the chance of survival. Despite years of research, Dr. Harkins noted that many questions remain unanswered, including why the disease can be mild for some and severe for others, and how antibodies develop. She and other researchers have been following patients over long periods to find a treatment. “A lot of mysteries,” she said, emphasizing that rodent exposure is a key factor.
The best way to avoid the germ is to minimize contact with rodents and their droppings. Use protective gloves and a bleach solution for cleaning up rodent droppings. Public health experts caution against sweeping or vacuuming, which can cause the virus to become airborne.
