Global Race to Track Hantavirus After Cruise Ship Outbreak

A global scramble is underway among health authorities to trace and prevent the spread of hantavirus, following the World Health Organization's Thursday confirmation of five infections tied to the plague-stricken cruise ship MV Hondius. Three individuals—a Dutch couple and a German national—have died since the vessel departed Argentina last month. South Africa's health ministry told CNN that the first suspected case involved a 70-year-old Dutch man who suddenly developed fever, headache, abdominal pain, and diarrhea aboard the ship, dying on April 11.

As of Thursday, 146 people from 23 countries, including 17 Americans, remain on board under "strict precautionary measures," according to operator Oceanwide Expeditions. While at least 30 passengers disembarked on the remote South Atlantic island of Saint Helena in late April, and several critical cases were airlifted to Europe this week, the remaining passengers are scheduled to reach Spain's Canary Islands this weekend before being flown home.

Passengers in Isolation, Doctor Steps In

Spanish authorities reported the ship will arrive in Tenerife around noon local time on Sunday. Speaking to CNN from the stricken vessel, Dr. Steven Cornfield, a vacationing physician, described how he had to step up after the medical crew fell ill. "Over 12 to 24 hours, it became clear that a number of people were sick and getting worse. I took over the role of ship's doctor," he said. Dr. Cornfield, who has spent the last five weeks on board, noted that most passengers had little to no contact with those showing symptoms: "People on the ship have been in quarantine and isolation for three or four weeks, so I feel most will leave relatively quickly."

The situation has drawn international attention, as some passengers had already left the ship and dispersed across multiple countries before the outbreak was fully understood, prompting comparisons to the early days of the COVID-19 pandemic. Oceanwide Expeditions said Thursday they are working to "identify details of all passengers and crew who boarded and disembarked at various stops of the MV Hondius since March 20," amid fears of global spread.

WHO Downplays Pandemic Risk, Traces Source

The WHO stated that while more cases are expected, it does not foresee a major outbreak anywhere akin to COVID-19, emphasizing there is no evidence of widespread transmission risk. The outbreak has been linked to the Andes strain of hantavirus, a rare but potentially severe virus that can, in some cases, spread between humans through close contact. How the outbreak began remains unclear, but the WHO is working on the assumption that the deceased Dutch couple contracted the virus outside the ship, possibly during a tour in Argentina before joining the cruise.

WHO Director-General Tedros Adhanom Ghebreyesus said, "The couple traveled on a birdwatching trip across Argentina, Chile, and Uruguay, including visits to sites where the rat species known to carry the virus is present." Given hantavirus's incubation period of one to six weeks, health officials say the couple likely fell ill some time after infection.

Retracing the Dutch Couple's Steps

Argentina is now reconstructing the route taken by the Dutch couple before they boarded the MV Hondius in Ushuaia on April 1, aiming to pinpoint the infection source. The Argentine health ministry reported no cases linked to the cruise ship outbreak have been identified in Argentina so far, and no hantavirus cases have been recorded in Ushuaia in recent decades. However, the virus is endemic in some parts of the country, and authorities found the couple, after arriving in Argentina on November 27, crossed the border back and forth with neighboring Chile several times before joining the cruise. On January 31, they re-entered Argentina from Chile through Neuquén province in the Sur region, also visiting Misiones in northeastern Argentina—both areas previously identified by the WHO as hantavirus-endemic. On March 13, the couple left Argentina for Uruguay by land, returning on March 27 to travel to Ushuaia, where the cruise departed on April 1. Technical teams will travel to Ushuaia to trap and test rodents in areas linked to the couple's route as part of the investigation.

Argentina, which announced its withdrawal from the WHO last year, is expected to send biological materials and laboratory reagents to Spain, Senegal, South Africa, the Netherlands, and the United Kingdom to support case diagnosis and study. The WHO stated on social media it is "working with affected countries to support international contact tracing, to ensure monitoring of those potentially exposed and limit any further spread of the disease."

Countries Monitoring and Treating Passengers

• Netherlands: Three evacuated passengers—a British citizen, a 65-year-old German, and a 41-year-old Dutch crew member—arrived for treatment. Two are in serious condition; the third, currently asymptomatic, is also receiving medical care.
• South Africa: A British citizen who fell ill on April 27 was transferred to a private medical facility in Johannesburg, where he remains in intensive care. He is the second confirmed hantavirus case; the WHO says his condition is improving.
• Switzerland: A passenger who returned to Switzerland after leaving the ship tested positive and is being treated in Zurich.
• United Kingdom: Two British citizens who left the ship in Saint Helena on April 24 are self-isolating at home as a precaution after potential exposure. The UK Health Security Agency is aware of five other British nationals who disembarked that day, including four still there, and contact tracing is ongoing for a seventh person who has not returned to the UK.
• United States: Health authorities are monitoring several people, including at least three who left the ship earlier and returned home. A Virginia resident who left the ship is being monitored by state health authorities but is currently well. Virginia's health department said a small number, fewer than 5, of "potentially exposed Virginia residents may be identified in the coming days." Health officials are monitoring two people in Texas who were also on board; they had no contact with sick passengers and report no symptoms. Officials in Georgia said two residents are under observation and asymptomatic, while Arizona health authorities said one person is also asymptomatic. California health authorities are monitoring an undisclosed number of people, with no information suggesting they are ill or infected.
• Singapore: The infectious disease agency said Thursday that two residents, both men in their 60s, are self-isolating and being tested for hantavirus. One has a runny nose but is otherwise well; the other is asymptomatic.
• Canada: Government officials said three people are self-isolating, including two in Ontario and one in Quebec. One of these individuals was not on the cruise but was on the same return flight home with Canadians who were on the ship.
• France: Eight French citizens who were not on the cruise have been identified as close contacts of a confirmed case. They were on an international flight on April 25, 2026, between Saint Helena and Johannesburg, which also carried the confirmed infected person. One individual has "mild symptoms," with diagnostic tests underway and isolation measures in place.