After a suspected hantavirus outbreak was identified on a long expedition cruise, health authorities said they mapped a chain of illnesses and deaths across multiple stops—spanning the South Atlantic and later reaching Cape Verde—before laboratories confirmed the infections in South Africa and Switzerland.
The MV Hondius, operated by Dutch cruise company Oceanwide Expeditions, offers “expedition cruises” that last a month or more and include trips to Antarctica and islands in the South Atlantic, according to information cited by the World Health Organization. The ship departed southern Argentina on April 1 and then took a route that included stops near remote islands such as Tristan da Cunha and St. Helena, before heading toward Cape Verde and, ultimately, Spain’s Canary Islands.
The timeline began, WHO said, with a 70-year-old Dutch man who developed fever, headache and diarrhea on April 6. The ship continued its voyage for nearly two weeks after his illness, and the man died on board on April 11 while the vessel was between the British island territories of South Georgia and St. Helena in the middle of the South Atlantic, according to MarineTraffic ship-tracking data cited in the report. Oceanwide Expeditions said the cause of death could not be determined.
WHO said the Dutch man’s 69-year-old wife disembarked at St. Helena, where the man’s body was removed on April 24. The woman, WHO said, already had symptoms, became sicker during an April 25 flight to South Africa, and collapsed at an airport there, later dying in a hospital on April 26.
Separately, the report said a patient who left the ship earlier in the voyage tested positive for hantavirus in Switzerland. The Swiss authorities announced that positive test on Wednesday, while the report noted that the person’s movements after leaving St. Helena were not clear.
A second confirmed case involved a British passenger who became sick after the ship left St. Helena and sailed to Ascension Island, about 1,300 kilometers (800 miles) north, WHO said. The passenger, WHO said, developed a high fever, shortness of breath and signs of pneumonia, and was evacuated from Ascension Island to South Africa on April 27. WHO said the passenger was in intensive care in South Africa.
WHO said a third fatality involved a German woman who died on the ship on Saturday, after the vessel had set sail for Cape Verde. WHO said she died four days after falling ill and had signs of pneumonia; the report said her body remained on the ship.
The sequence between the first death and laboratory confirmation stretched across distant locations. The report said there was nearly a month between when the Dutch man fell ill and died in the South Atlantic and when laboratory tests in South Africa first confirmed hantavirus infections. Health officials in South Africa tested the British man in intensive care after tests for other ailments were negative, and WHO said they received the positive result for hantavirus on Saturday—21 days after the first passenger died.
According to WHO, the British man’s positive test prompted South African health authorities to test the Dutch woman’s body, with that result coming back positive on Monday. WHO said Swiss authorities announced the positive test for the man in Switzerland on Wednesday, and that contact tracing was underway.
WHO said tests on patients in South Africa and Switzerland showed the infection was a hantavirus found in South America, called the Andes virus. Hantaviruses, WHO said, usually spread through inhaling contaminated rodent droppings, and while they can spread person-to-person, that is rare, with the WHO’s top epidemic expert saying the risk to the public is low.
With the outbreak detected, authorities moved to contain possible exposures. After waiting off Cape Verde for three days, the report said the ship headed to the Canary Islands, where Spain said it would accept it. WHO said passengers and crew were isolated in cabins with physical distancing, described in the report as a lockdown reminiscent of the COVID-19 pandemic; the report said the ship still carried more than 140 passengers and crew as it departed Cape Verde for Spain’s Canary Islands.
The report said WHO and investigators were also working to identify how the virus got aboard. WHO said it was investigating how a relatively rare hantavirus in people entered the ship. The Argentine government’s leading hypothesis, the report said, was that the Dutch couple contracted the virus during a bird-watching outing in Ushuaia before boarding, citing two investigators who spoke anonymously because they were not authorized to brief the media, with the investigation ongoing.