How a deadly hantavirus outbreak unfolded on a cruise ship for weeks before it was identified

CAPE TOWN, South Africa (AP) — A deadly outbreak of the rare hantavirus unfolded over the course of weeks on a cruise ship that sailed from Argentina toward Antarctica and then across the Atlantic Ocean, stopping at or near remote islands on the way as passengers and crew members fell sick, according to information from the cruise operator, the World Health Organization and ship tracking data.

It shows nearly a month passed between when an elderly Dutch man fell sick and died in the South Atlantic and laboratory tests in South Africa — more than 3,500 kilometers (2,174 miles) away — confirmed hantavirus infections.

Three passengers in total have died, one is in intensive care in a South African hospital, and three other people still on the cruise ship have shown symptoms and were waiting for evacuations. Nearly 150 passengers and crew members from 23 countries were on the ship, which is waiting off the coast of West Africa.

Hantavirus is spread by rodents. People can get it through contact with infected rodents' saliva, urine or droppings. It doesn’t usually spread from person to person, but some health authorities say such transmission could be possible.

While only two hantavirus cases related to the ship have been confirmed through tests, WHO suspects the others also are hantavirus and is treating it as an outbreak. It is still investigating the source.

What happened on the ship

The Dutch company that operates the ship, the MV Hondius, offers “expedition cruises” that involve trips to the Antarctic and several islands in the South Atlantic to see some of the remotest places on earth.

The cruises can last a month or more and cost between $6,000 and $25,000, depending on the cabin.

The MV Hondius set off from southern Argentina on April 1.

On April 6, the 70-year-old Dutch man fell ill with fever, headache and mild diarrhea, WHO said.

He died on board on April 11, after developing respiratory distress. The ship was between the British island territories of South Georgia and St. Helena in the middle of the South Atlantic, according to data from the ship tracking website MarineTraffic. The cause of death could not be determined, according to the cruise company, Oceanwide Expeditions.

The ship sailed on for nearly two weeks, stopping near the island of Tristan da Cunha before it reached St. Helena, where the Dutch man's body was taken off the ship on April 24. His 69-year-old wife disembarked with his body and flew to South Africa, while the man's body remained behind.

The woman, who already had symptoms, became sicker during the April 25 flight and collapsed at an airport in South Africa. She died at a hospital on April 26, WHO said.

Another passenger, a British man, became sick on the ship after it left St. Helena and sailed to tiny Ascension Island, some 1,300 kilometers (800 miles) north. He had a high fever, shortness of breath and signs of pneumonia, according to WHO, and was evacuated from Ascension Island to South Africa on April 27. He is in an intensive care unit in a South African hospital.

The third fatality, a German woman, died on the ship on Saturday, again after it had set sail for a new destination — this time Cape Verde. She died four days after falling ill and also had signs of pneumonia, WHO said, which can be caused by hantavirus. Her body is still on the ship.

When authorities first knew hantavirus was on the ship

Health officials in South Africa ultimately tested the British man in intensive care for hantavirus after other extensive tests on him were negative. They received a positive result for hantavirus on Saturday, some 21 days after the first passenger died.

On Sunday, WHO announced it was investigating a suspected hantavirus outbreak on the ship, which had by that time reached Cape Verde waters.

The British man's positive test prompted South African health authorities to also test the Dutch woman's body posthumously for hantavirus. That test came back positive on Monday.

WHO said the outbreak on the ship was being managed and the global risk was low as hantavirus is not easily spread between people, though it added it was tracing people who were on a passenger plane between St. Helena and Johannesburg, South Africa, with the Dutch woman.

What the plan is for the people still on board

Oceanwide Expeditions said Tuesday that aircraft were flying to Cape Verde to evacuate two people needing urgent medical care and one passenger who was traveling with the German woman who died Saturday. They were to be taken to the Netherlands, but a timeline for arrival wasn’t clear.

The ship then would sail to Spain’s Canary Islands, a voyage of about three days, the company said.

Spanish officials had said they were monitoring and hadn’t confirmed any plans as of Tuesday evening.

Passengers and crew have been isolated in cabins with “maximal physical distancing,” WHO said, in a lockdown reminiscent of the COVID-19 pandemic.

The source of the infections

WHO says it is still investigating how a virus that is relatively rare in people got on board the ship. It said the Dutch man and his wife — who it called cases one and two — had traveled in Argentina and elsewhere in South America before they boarded.

WHO says Andes virus, a specific species of hantavirus, is found in South America, primarily in Argentina and Chile.