The World Health Organization is coordinating a multi-country response to a hantavirus outbreak that began aboard a Dutch-flagged cruise ship in the South Atlantic, with cases or close contacts now traced across more than 12 countries on four continents. Eight infections, including three deaths, have been linked to the MV Hondius, operated by Oceanwide Expeditions, after the vessel departed Argentina in early April for what was meant to be a remote-island expedition cruise.
The international scramble to identify potentially exposed travelers reflects the geographically dispersed nature of cruise tourism, where passengers from dozens of nationalities can disembark at multiple ports before any outbreak is recognized. While the WHO has assessed the global public health risk as low, the response has drawn comparisons to the early days of the COVID-19 pandemic, when slow tracing of disembarked passengers complicated containment.
The Andes Virus and Why This Outbreak Is Different
Five of the eight reported cases have been laboratory-confirmed as the Andes virus, a rare strain of hantavirus endemic to parts of South America. According to the European Centre for Disease Prevention and Control (ECDC), Andes virus is the only hantavirus species documented as capable of limited human-to-human transmission, typically through close and prolonged contact rather than casual exposure.
Most hantavirus infections globally are acquired through contact with the urine, feces, or saliva of infected rodents. The Andes virus causes Hantavirus Pulmonary Syndrome, marked by fever, gastrointestinal symptoms, and rapid progression to pneumonia, acute respiratory distress, and shock. There is no specific antiviral treatment; supportive care in intensive care units offers the best chance of survival.
The current working hypothesis from health authorities is that some passengers were exposed to the virus while spending time in Argentina before boarding the ship on April 1, with limited onward transmission to close contacts during the voyage. Argentina’s health ministry reported 101 hantavirus infections in the country since June 2025, roughly double the caseload of the prior year, according to the Associated Press.
Tracking Cases Across Continents
The geographic footprint of the response has expanded rapidly. According to WHO and CNN reporting, confirmed cases, suspected cases, or close contacts have been identified in Switzerland, Singapore, Canada, France, the United Kingdom, Germany, the Netherlands, Spain, the United States, and several other countries.
In Switzerland, a man who traveled on the MV Hondius tested positive for the Andes strain and is being treated at the University Hospital Zurich. Singapore’s Communicable Diseases Agency said two men in their 60s are self-isolating and undergoing testing. Canadian authorities are monitoring three individuals self-isolating in Ontario and Quebec, including one person who shared a flight home with two passengers from the cruise. France has identified eight nationals as close contacts of a confirmed case based on a shared April 25 flight from Saint Helena to Johannesburg.
The MV Hondius carried 149 people from 23 nationalities at the start of the voyage. Roughly 30 passengers disembarked at the remote South Atlantic island of Saint Helena in late April. Several critical patients have since been medically evacuated to Europe and South Africa.
What WHO Is Doing
The WHO has deployed an expert aboard the ship to support medical assessment of all remaining passengers and crew while gathering data on infection risk. The agency has shipped 2,500 diagnostic kits from Argentina to laboratories in five countries to expand testing capacity, according to its May 7 statement.
“While this is a serious incident, WHO assesses the public health risk as low,” WHO Director-General Dr. Tedros Adhanom Ghebreyesus said at a media briefing on May 7, while warning that “given the incubation period, it’s possible that more cases may be reported.”
The WHO is coordinating its response through the International Health Regulations framework, which defines the obligations of member states during cross-border health events. The ECDC, working with EU member states, has issued separate guidance on infection prevention, including standard and droplet precautions for healthcare workers treating symptomatic patients.
What Comes Next
The MV Hondius is scheduled to dock in Tenerife, Canary Islands, on May 10, 2026, after Spanish authorities agreed to receive the ship. Spain is preparing to handle more than 140 passengers and crew on arrival, with quarantine and testing protocols in place.
For the broader cruise industry, the outbreak underscores the persistent challenge of managing public health risks aboard floating cities of international travelers. For public health authorities, the response represents a stress test of the post-COVID international tracing architecture, showing both how quickly information can move between countries and how easily exposed travelers can disperse before an outbreak is fully understood.
Whether the case count remains contained at single digits or rises in the coming weeks will depend largely on how comprehensively the dozens of disembarked passengers and their contacts are identified and monitored across the continents now folded into the response.
