A rare hantavirus outbreak linked to an expedition cruise ship near South America has drawn international attention and renewed concerns about emerging infectious diseases. While experts emphasize that the risk of a widespread outbreak remains extremely low, the appearance of Andes virus-associated hantavirus pulmonary syndrome on a cruise ship has raised questions about global preparedness, travel-related transmission, and public understanding of infectious disease threats.

A rare hantavirus outbreak linked to an expedition cruise ship near South

America has drawn international attention and renewed concerns about emerging infectious diseases. While experts emphasize that the risk of a widespread outbreak remains extremely low, the appearance of Andes virus-associated hantavirus pulmonary syndrome on a cruise ship has raised questions about global preparedness, travel-related transmission, and public understanding of infectious disease threats.

Matthew Pullen, MD, an infectious disease physician and member of the Infection Control Today® Editorial Advisory Board, said much of the concern stems from confusion about the virus itself.

“Hantavirus is actually a very large family of viruses,” Pullen explained. “The ones we’re hearing about most right now are the Sin Nombre virus and Andes virus.”

According to Pullen, Sin Nombre virus is the hantavirus most commonly found in the United States and is transmitted through infected deer mice. Andes virus, first identified in Argentina and Chile, has generated greater concern because of limited evidence suggesting possible human-to-human transmission.

“There are a few cases where they’re pretty confident there was human-to-human transmission,” Pullen said. “But there’s still academic debate about whether some of those outbreaks represented true transmission or simply shared exposure.”

Both viruses can cause hantavirus pulmonary syndrome, a severe disease with a case fatality rate approaching 40%.

“It starts like a flu-like illness,” Pullen said. “Body aches, headaches, fever, nausea, vomiting. Then the severe cardiopulmonary phase develops, and that’s what kills people.”

Despite the seriousness of the illness, Pullen stressed that fears of a COVID-19-like pandemic are unsupported by current evidence.

“I would say the likelihood is very, very, very low,” he said.

One reason is the virus's limited transmissibility.

“It doesn’t spread like COVID[-19] does. It doesn’t spread like the flu does,” Pullen said. “The last estimate I saw had an R-naught of about 1.2, meaning not every case even propagates to another case.”

Pullen also questioned whether current monitoring measures surrounding the cruise ship outbreak are sufficient.

“While balancing public health with patient autonomy is important, there are still seemingly unanswered questions about the transmission and exposure events in this outbreak,” Pullen told Infection Control Today®. “This raises concerns about the current monitoring strategy, especially as compared to other nations that have repatriated citizens from the ship and are following tighter monitoring plans.”

More than the virus itself, however, Pullen worries about the social environment surrounding emerging disease events.

“What worries me most actually isn’t the virus itself,” Pullen said. “It’s the social conditions around the virus.”

He pointed to rapidly changing narratives on social media.

“One morning, people on social media were saying this was going to be the next pandemic that would kill us all,” he said. “By that afternoon, those same people were posting that hantavirus was nothing to worry about and that the government was lying.”

Pullen also warned about individuals attempting to profit from public fear.

“There was even a physician online promoting ivermectin as a cure for hantavirus,” Pullen said. “Then conveniently mentioning they also sell ivermectin.”

For clinicians, awareness remains important despite the rarity of the disease.

“If someone comes in with severe pulmonary syndrome after traveling through Argentina or Chile, that should absolutely bubble up in your mind,” he said.

Pullen believes most US hospitals already have the infection prevention infrastructure necessary to manage suspected cases.

“Every hospital should be equipped to do respiratory isolation and airborne precautions,” he said. “The key is recognizing the syndrome early and escalating appropriately.”

Still, he expressed concern about broader public health capacity.

“The people working at CDC are phenomenal,” he said. “But they’re being hamstrung by funding limitations and policy decisions.”

Ultimately, Pullen said the outbreak serves as another reminder that emerging zoonotic diseases will remain a global challenge.

“Viruses don’t respect borders,” he said. “And the more interconnected the world becomes, the more important preparedness, communication, and public trust become.”