Hantavirus Outbreak on Cruise Ship: What You Need to Know About the Rare Virus

(Photo illustration by The Bulwark / Photos: Getty)

It sounds like the premise of a horror film: a small ship crossing the South Atlantic with roughly 150 tourists, exploring remote lands and rare birds, when an older man suddenly develops fever and a cough—and dies. Symptoms soon appear in a half dozen more passengers and crew, including the ship’s doctor, and the death toll rises to three. Testing confirms they’ve been infected with an animal-borne virus that rarely spreads from person to person.

By this point, more than 30 passengers have already disembarked and scattered across a dozen countries, prompting a frantic effort by health authorities to locate and isolate them. The remaining passengers remain on board, isolated under medical observation to monitor for further cases. There is no cure for the disease.

If you’ve been following the headlines, you know this isn’t fiction. It’s the real-life story of a hantavirus outbreak aboard the MV Hondius, an expedition vessel that departed Argentina in April. The good news—yes, there is good news—is that this outbreak is unlikely to escalate into a mass-scale crisis.

The form of hantavirus known to spread among humans is thought to transmit for a relatively short window during symptoms, primarily through prolonged, close contact. This is very different from COVID-19, which was airborne and could spread before symptoms appeared. With hantavirus, contact tracing stands a better chance of identifying exposed individuals—most of whom are unlikely to contract the disease.

“We have contained this in the past and I’m very confident it’s going to be contained again. To the average person, your risk is essentially nil.”
— Katelyn Jetelina, former CDC consultant and founder of Your Local Epidemiologist

Yet public health professionals express a clear level of concern—not just because any lethal virus warrants vigilance, but because of the broader erosion of America’s global health infrastructure under the current administration.

Donald Trump’s second presidency has seen an all-out assault on these systems: downsizing or eliminating agencies, repurposing them for unrelated goals like mineral rights extraction or ending DEI initiatives, withdrawing from the World Health Organization, and reducing global health cooperation. The result is a federal response to outbreaks that is weaker overall and may struggle to handle a more serious threat.

What Is Hantavirus? Transmission, Symptoms, and Risks

Hantavirus is primarily a rodent-borne disease. Estimates suggest it infects tens of thousands of people worldwide each year, though severe cases remain rare. The virus is typically transmitted to humans through contact with infected rodents or their droppings, urine, or saliva.

Human-to-human transmission is uncommon but has been documented in rare cases, particularly with the Andes virus in South America. Symptoms often include:

• Fever
• Fatigue
• Muscle aches
• Headaches
• Chills
• Nausea and vomiting
• In severe cases: difficulty breathing due to hantavirus pulmonary syndrome (HPS)

The Centers for Disease Control and Prevention (CDC) notes that HPS has a mortality rate of approximately 38%. However, early medical intervention can significantly improve outcomes.

How the MV Hondius Outbreak Unfolded

The MV Hondius, an expedition ship operated by Hurtigruten Expeditions, set sail from Argentina in April. Onboard were roughly 150 passengers and crew, including scientists, birdwatchers, and adventure travelers.

According to reports, the first case emerged when an older male passenger developed fever and respiratory symptoms. Despite medical attention, his condition deteriorated rapidly, and he died. Subsequent testing confirmed hantavirus as the cause. Within days, additional passengers and crew members fell ill, including the ship’s doctor.

By the time health authorities identified the outbreak, over 30 passengers had already disembarked in multiple countries, including Uruguay, Brazil, and South Africa. Contact tracing efforts were immediately launched to locate and monitor exposed individuals.

The remaining passengers and crew were placed under quarantine on the ship, with medical teams conducting daily health checks. No new cases have been reported since the initial cluster, and authorities express cautious optimism about containment.

Why Experts Are Concerned Despite Low Public Risk

While the risk to the general public remains minimal, public health experts warn that the current state of global health infrastructure could hinder future outbreak responses.

Key concerns include:

• The withdrawal from the World Health Organization (WHO), reducing international collaboration.
• Budget cuts and staffing reductions in agencies like the CDC and National Institutes of Health (NIH).
• Repurposing of health agencies for unrelated political or economic goals.
• Erosion of pandemic preparedness programs established after COVID-19.

“The infrastructure we built to respond to pandemics is being dismantled,” said a former senior CDC official who requested anonymity. “If a more transmissible or deadly pathogen emerges, we may not have the tools to respond effectively.”

What Should Travelers and the Public Do?

For now, health authorities emphasize that the risk of hantavirus transmission from the MV Hondius outbreak is low. However, they recommend the following precautions:

• Monitor travel advisories for updates on exposed passengers and crew.
• Avoid contact with rodents and their habitats, especially in rural or wilderness areas.
• Practice good hygiene, including handwashing after outdoor activities.
• Seek medical attention immediately if fever, muscle aches, or respiratory symptoms develop after potential exposure.

The CDC and World Health Organization (WHO) continue to monitor the situation and provide guidance as needed.