Three passengers are dead and eight are infected with Andes hantavirus after an outbreak aboard the MV Hondius, a polar expedition cruise ship that docked this week at the port of Granadilla in Tenerife, where 94 people began stepping off the vessel and onto repatriation flights bound for their home countries. The outbreak now spans five countries, and the World Health Organization has classified it as an event under the International Health Regulations, a designation that compels member states to coordinate surveillance and share data. It is one of the most serious disease incidents on a cruise ship in years, and it involves a virus with a trait that makes containment especially urgent: Andes hantavirus is the only known hantavirus strain that can spread directly from person to person.
The outbreak so far
As of May 10, 2026, the European Centre for Disease Prevention and Control reports six confirmed and two probable Andes hantavirus infections linked to the Hondius, with three deaths. The ship is operated by Oceanwide Expeditions, a Dutch company that runs small-vessel expedition cruises to Antarctica, the Arctic, and other remote destinations. The Hondius had been sailing from South America through the Atlantic before arriving in the Canary Islands.
The situation escalated quickly in early May. The WHO received its initial notification on May 2, after early cases presented with severe respiratory illness and rapid deterioration. By May 6, the ECDC had counted seven cases, including the three fatalities, and activated the EU Early Warning and Response System to alert member states about passengers who had already left the ship at earlier ports.
The WHO then took the unusual step of deploying an expert directly aboard the Hondius while it was still at sea, shipping diagnostic kits to the vessel and issuing operational guidance for how passengers should safely disembark. A multi-country Disease Outbreak News bulletin formalized the response and triggered mandatory reporting obligations for every country receiving returning passengers.
One case underscores how far the virus may have already traveled. An American passenger evacuated from the ship in Tenerife tested positive for hantavirus but showed no symptoms at the time, according to reporting that identified Nebraska Medical Center as the receiving facility. U.S. authorities arranged quarantine protocols for the passenger’s return. That asymptomatic positive result raises a pressing question: how many other passengers who left the ship at earlier stops may be carrying the virus without realizing it?
Why Andes hantavirus worries health officials
Most hantaviruses spread to humans through contact with infected rodents or their droppings and do not pass between people. Andes hantavirus breaks that pattern. Research published over the past two decades, including studies from outbreaks in Argentina and Chile, has documented person-to-person respiratory transmission of this strain. That capacity is what separates this outbreak from a typical hantavirus exposure event and is the reason the WHO and ECDC have treated it with the urgency normally reserved for pathogens like Ebola or MERS.
The virus causes hantavirus cardiopulmonary syndrome, which can progress from flu-like symptoms to respiratory failure within days. Historical case fatality rates for Andes hantavirus infections range from roughly 30 to 40 percent, though outcomes depend heavily on how quickly patients receive intensive supportive care. There is no approved antiviral drug or vaccine for any hantavirus. Treatment relies on oxygen support, fluid management, and, in severe cases, mechanical ventilation or extracorporeal membrane oxygenation.
On a cruise ship, the combination of shared dining spaces, narrow corridors, and recirculated air creates conditions that could amplify person-to-person spread. Whether that mechanism drove this particular cluster or whether cases resulted from a common rodent exposure at a port of call remains unknown. Answering that question will likely require genomic sequencing of the virus from multiple patients, data that investigating agencies have not yet made public.
What remains unknown
Several critical gaps persist. No public reporting has identified where or how the first passenger became infected. If the initial exposure involved rodents at a shore excursion site in South America, the risk profile differs sharply from a scenario in which the virus spread from person to person aboard the ship itself.
The identities and nationalities of the deceased and infected passengers have not been broken out by country in WHO or ECDC summaries. The outbreak is described as spanning five nations, but which five and how cases are distributed among them has not been specified. National health ministries have cited privacy protections in declining to release individual travel histories.
The total number of people potentially exposed is also unclear. The Hondius carried passengers and crew through multiple stops before reaching Tenerife, and some individuals disembarked at earlier ports before the outbreak was recognized. The full passenger manifest has not been made public, making the true scope of exposure difficult to gauge. That uncertainty extends to port workers, local medical staff, and transport personnel who may have had close contact with sick passengers before the diagnosis was confirmed.
Early outbreak numbers almost always undercount the true total. Andes hantavirus has an incubation period that can stretch to several weeks, so some passengers may still be developing infections. As laboratories in receiving countries begin testing for the virus, case numbers could rise without necessarily indicating wider community spread.
Contact tracing across continents
Health agencies in Europe and beyond are now working from passenger manifests and flight itineraries to identify people who shared cabins, dining tables, or excursion groups with confirmed cases. Passengers seated near infected individuals on repatriation flights are also being traced. The logistical challenge is significant: 94 people disembarked in Tenerife alone, and others left the ship at earlier ports, meaning contacts are now scattered across multiple countries and time zones.
The IHR designation obligates every WHO member state receiving a returning passenger to report suspected cases promptly and apply agreed-upon control measures. In practice, that means national public health agencies should already be reaching out to passengers on their territory, arranging testing, and advising self-monitoring or isolation where appropriate.
For anyone who traveled on the Hondius or visited the same ports during its voyage, the most important step is to contact a local health authority or physician immediately, report the potential exposure, and ask about monitoring protocols. Even passengers who feel healthy should not assume they are uninfected, given the long incubation window. Symptoms to watch for include fever, muscle aches, headache, abdominal pain, and shortness of breath. Breathing difficulties in particular warrant urgent medical attention. Clinicians should be told about the Hondius connection so they can order the correct tests; many laboratories will not screen for Andes hantavirus unless prompted by a specific exposure history.
What comes next
The coming weeks will determine whether this outbreak remains a contained cluster tied to a single ship or expands as more passengers are tested. Genomic sequencing results, when released, should clarify whether all cases trace back to one introduction event or to multiple exposures, and whether the virus shows any mutations affecting transmissibility. The WHO and ECDC have both indicated they will continue publishing situation updates as new information becomes available.
For the broader public, the current evidence points to a tightly defined outbreak, not sustained community transmission. But the combination of a high-fatality pathogen, confirmed person-to-person spread capability, and passengers now dispersed across at least five countries means this is a story that public health officials will be watching closely for weeks. Following updates from the WHO and ECDC will provide the most reliable picture of whether the situation is stabilizing or growing.
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*This article was researched with the help of AI, with human editors creating the final content.
