Where is he, what to know

A hantavirus outbreak on a cruise ship has shaken the public and reignited fears of a new global health scare as passengers scatter across several countries, including the United States.

On Wednesday, the World Health Organization reported 11 cases linked to the outbreak, eight of which were confirmed. including three deaths. While the CDC said Thursday that 41 people in the United States were being monitored for hantavirus, there are no confirmed cases in the country.

It will still take years to find specific treatments against hantavirus: actions of Modern rose about 12% on Friday after confirming it was conducting preliminary research on a potential vaccine to protect against hantavirus.

But as the number of people exposed and public concern increases, health experts aim to allay fears of another pandemic. Their message: it’s not Covid-19 again.

Unlike Covid, measles or the flu, the specific Andean strain of hantavirus present in the outbreak does not spread easily between people, making the risk of widespread spread to the public low. More cases could emerge in the coming weeks because hantavirus has a long incubation period, experts say.

Still, “we do not expect large numbers of infections and they will likely remain limited to passengers who were exposed on board the ship, especially now that we have containment measures in place,” Dr. Nicole Iovine, the hospital’s chief epidemiologist and infectious disease physician at the University of Florida, said in an interview.

But for other experts, the outbreak raises broader concerns about the United States’ ability to respond to future infectious disease threats, particularly after major budget cuts at the Centers for Disease Control and Prevention and the Trump administration’s decision to withdraw from the WHO last year.

While experts say the CDC appears to have the hantavirus outbreak under control, some warn the situation has exposed cracks in the nation’s public health infrastructure that could have more serious consequences when faced with a more contagious pathogen.

“I don’t expect any significant risk to the American public. But if this is a stress test, we have failed,” said Lawrence Gostin, a professor of public health law at Georgetown University. “Imagine if this was actually a highly transmissible agent.”

Here’s what you need to know about the status of the hantavirus outbreak and what it says about the United States’ ability to contain infectious diseases.

The risk of this hantavirus to the general public remains low, according to WHO public health experts. This is largely because hantavirus does not spread as easily as other viruses like Covid.

Hantavirus is primarily transmitted to humans through contact with infected wild rodents, including inhalation of airborne particles from their urine, feces, or saliva. Cases of hantavirus disease are rare in the United States: from 1993 to 2023, 890 cases have been reported, most in Western states, according to CDC data.

The Andean strain of the virus seen in the outbreak – and found in South America – is the only hantavirus that can spread from human to human. However, there are few cases of human-to-human transmission, so the medical community takes clues from previous outbreaks.

The Andes strain typically spreads through “close and usually prolonged contact” with an infected person with symptoms, said Dr. Kari Debbink of the Johns Hopkins Bloomberg School of Public Health.

Debbink said it’s not the same as Covid, which “spreads quite effectively without very long exposure.” Hantavirus is not considered airborne because it does not linger in the air to infect others in the same way as respiratory viruses like Covid, flu and measles.

But cruise ships like the MV Hondius are considered ideal environments for disease transmission because they bring together a wide variety of people and pack them in close quarters for days or even weeks.

“Cruise ships are one of the biggest threats to public health. They are floating petri dishes isolated in the water,” said Dr. Tyler Evans, CEO of the public health organization Wellness Equity Alliance and former chief medical officer of New York City’s Covid response.

WHO investigators believe the outbreak originated from a Dutch couple aboard the cruise ship MV Hondius, who later died from their infections.

Before boarding, the couple had taken a bird-watching trip through Argentina, Chile and Uruguay, Dr. Tedros Adhanom Ghebreyesus, WHO director-general, said at a May 7 press briefing. He said the couple’s birding trip included visits to sites where “the rat species known to carry hantavirus was present,” he said.

Hantavirus has an incubation period of one to six weeks after exposure, meaning more cases will likely arise, Debbink said. But people who have come into contact with infected people are monitored for symptoms in specialized facilities, so “this should be contained fairly quickly”, she added.

The United States likely has the outbreak under control given the nature of hantavirus. But some health experts have expressed concerns about the lack of a stronger response from the CDC under President Donald Trump, and expressed broader fears about whether the United States is prepared for future, more transmissible global health threats.

“CDC has always been at the forefront of global health emergencies – from SARS-CoV-2 to Ebola to Zika,” said Georgetown’s Gostin. “And for that, the CDC is absent. Their response has been disjointed and late.”

For decades, the CDC gained a reputation as the world’s premier public health agency, quickly coordinating with the WHO and foreign governments during outbreaks. But experts say the agency has been weakened by deep staff cuts, vacancies at the top of the organization and the Trump administration’s decision to cut ties with the WHO.

Trump cut about 10% of the CDC’s workforce in early 2025, leaving fewer epidemiologists and scientific staff to do field work or coordinate responses across governments. There is currently no permanent CDC director or U.S. surgeon general, two positions that play critical roles in responding to disease threats.

“They don’t have the right leadership at the CDC,” Evans said. “They’re kind of on a ship without a captain at the helm, so they’re scrambling a little bit and doing the best they can. That raises serious concerns.”

Gostin said the CDC was lagging behind the WHO and European health authorities, saying the agency had stepped up its actions “a week after the international community began mobilizing around a potential global health crisis.” The outbreak was first reported on May 2 to the WHO, which quickly took a number of measures, including deploying an expert on board the ship.

The CDC issued its first public statement on the outbreak on May 6 and its first official health alert to U.S. doctors on May 8, which warned of the possibility of imported cases. The agency confirmed it deployed a team on May 7 to Spain’s Canary Islands, where the ship arrived two days later, as well as a second group to Nebraska, as part of a plan to evacuate the ship’s American passengers.

With the CDC now working with the WHO, experts say the Trump administration’s decision to cut ties with the international health body is detrimental to the United States’ ability to respond to future outbreaks. For example, the United States no longer has direct and automatic access to real-time information from WHO member states on emerging health threats.

Neil Maniar, a professor of public health at Northeastern University, said the response to hantavirus stands in stark contrast to 2020, when the CDC worked closely with international partners during Covid.

“That’s what it takes to effectively respond to these types of outbreaks, and that’s where the system really broke down,” Maniar said.

“We need to restore our country’s expertise and resources to respond, because there are going to be future outbreaks,” he added. “This should be a wake-up call for everyone in terms of our preparedness and our ability to keep this country safe.”