Hantavirus Outbreak on Cruise Ship Triggers Global Investigation as Cases Spread Across Continents

Health authorities in Argentina and several countries are investigating a hantavirus outbreak linked to the cruise ship MV Hondius, as concerns grow over whether the virus originated in South America and how far exposed passengers may have traveled after disembarking.

The vessel, which sailed from Ushuaia in southern Argentina toward Antarctica, has been connected to multiple confirmed infections, including fatalities and evacuations across several countries. Authorities say passengers tested positive for the Andes strain of hantavirus, a rare rodent-borne virus known in parts of South America.

Outbreak linked to South American Andes strain

Argentine health officials confirmed that the virus involved is the Andes variant, which can cause hantavirus pulmonary syndrome, a severe respiratory disease with a high fatality rate. The country’s health ministry reported 101 hantavirus cases since June 2025, roughly double the previous year, with mortality in nearly one-third of recent infections.

Three deaths have been recorded among passengers connected to the ship. A 70-year-old Dutch man died on April 11 while still onboard, with his body later removed at Saint Helena. His 69-year-old wife became ill, was evacuated to South Africa, and died in Johannesburg on April 26. A German woman died on May 2.

Authorities also confirmed a Swiss case involving a passenger who tested positive after leaving the ship earlier in the voyage.

Tracing possible exposure in South America

Investigators in Argentina are working to determine where infection may have occurred, focusing on passenger movements before boarding in Ushuaia. The Dutch couple reportedly traveled through Argentina, Chile, and Uruguay before boarding the vessel on April 1.

Officials said the virus has not been detected in Tierra del Fuego since 1996, complicating efforts to identify the exact point of infection. The incubation period, which can last between one and eight weeks, further complicates tracing efforts.

Argentina has dispatched technical teams from the Malbrán Institute to Ushuaia to capture and test rodents in areas linked to passenger routes. The Health Ministry said the measures are precautionary and confirmed that Andes virus RNA is being sent to Spain, Senegal, South Africa, the Netherlands, and the United Kingdom to support expanded testing capacity for up to 2,500 samples.

International monitoring and passenger follow-up

Health authorities in multiple countries are tracking passengers who disembarked the ship during its journey. Reports indicate that some individuals who left the vessel on Saint Helena on April 23 have since returned to their home countries, including the United States.

In the United States, the Centers for Disease Control and Prevention stated it is monitoring exposed passengers in several states, including Georgia, California, and Arizona. The agency emphasized the limited risk to the public, noting that transmission requires close contact and that asymptomatic individuals do not spread the virus.

A CDC statement said, “Hantavirus is not spread by people without symptoms, transmission requires close contact, and the risk to the American public is very low.”

In the United Kingdom, health authorities confirmed that two returning passengers are self-isolating despite showing no symptoms. One British national was previously evacuated for treatment in the Netherlands, while others onboard are being monitored.

German authorities are also conducting precautionary checks on an asymptomatic contact linked to a confirmed case, while other exposed individuals have been transferred for observation in the Netherlands.

Evacuations and medical transport complications

Several passengers and crew members have been evacuated from the MV Hondius, including expedition staff and medical personnel. A British expedition guide, a Dutch ship doctor, and a German passenger were among those removed during emergency operations.

Medical evacuations have involved air transfers from Cape Verde to Europe. One aircraft carrying suspected cases encountered technical issues involving its electrical support system, delaying transfer procedures. Another air ambulance was forced to reroute through Gran Canaria after Morocco denied refueling permission, before continuing toward the Netherlands.

A patient has since been admitted to Leiden University Medical Center under strict isolation protocols designed for severe infectious diseases.

Ship movement and port controversy

After evacuations, the MV Hondius continued its voyage toward the Canary Islands. Spain approved docking in Tenerife, but the decision triggered opposition from regional authorities in the Canary Islands, who said they had not received sufficient reassurance about public health risks.

The vessel, carrying around 150 people, was initially anchored near Cape Verde while arrangements were made for medical transfers. Spanish officials later confirmed that all passengers will be repatriated once the ship arrives, unless medically unable to travel.

Spain’s health ministry stated that the 14 Spanish nationals aboard will be transferred to a military hospital in Madrid.

WHO and global risk assessment

The World Health Organization has maintained that the outbreak does not represent a global pandemic risk. WHO Director-General Tedros Adhanom Ghebreyesus said the situation is being monitored closely but stressed that overall risk remains low.

He said, “The WHO continues to work with the ship’s operators to closely monitor the health of passengers and crew.” He added that coordination is ongoing with national authorities for medical follow-up and evacuations.

Tedros also dismissed comparisons with COVID-19, while experts such as Oxford University’s Andrew Pollard said the likelihood of wider transmission is extremely limited due to the virus’s transmission pattern.

Disease characteristics and transmission

Hantavirus infections typically begin with flu-like symptoms such as fever, headache, and abdominal or back pain, though some cases remain asymptomatic. In severe cases, particularly with the Andes strain, the disease can progress rapidly to respiratory failure due to fluid accumulation in the lungs.

In the Americas, hantavirus pulmonary syndrome can have fatality rates between 30% and 40%, while other strains in Europe and Asia cause hemorrhagic fever with kidney complications at lower but still significant mortality rates.

Transmission usually occurs through exposure to infected rodent droppings, urine, or saliva. Human-to-human spread is rare but has been documented in limited circumstances involving close contact with the Andes strain.

Climate concerns and outbreak context

Public health researchers in Argentina have linked the broader risk environment to climate change, suggesting that shifting temperatures may expand rodent habitats and increase opportunities for viral transmission.

Infectious disease specialist Hugo Pizzi said warmer conditions are altering ecosystems and enabling rodent populations to spread more widely. He noted, “Argentina has become more tropical because of climate change… there is no doubt that as time goes by, the hantavirus is spreading more and more.”