Three die in rare hantavirus outbreak aboard cruise ship MV Hondius

Three passengers died and four others fell ill in a rare hantavirus outbreak aboard the expedition cruise ship MV Hondius, a Dutch-flagged vessel carrying 147 people from 23 nationalities that remained anchored off Cape Verde on Tuesday.

The World Health Organization said its working assumption is that the pathogen is the Andes virus, a South American hantavirus strain notable for its capacity for limited human-to-human transmission. No vaccine or specific treatment exists for hantavirus, and WHO is arranging for the ship to proceed to Spain's Canary Islands for disinfection and investigation.

The MV Hondius, a 107.6-metre expedition vessel built in 2019, departed Ushuaia, Argentina, on April 1 carrying 88 passengers from 15 countries and 61 crew from 12 countries, according to The Korea Times. The ship called at South Georgia, Tristan da Cunha and Saint Helena before anchoring off Cape Verde after authorities there refused permission to dock.

Health investigators believe the source of the outbreak is a Dutch couple who had traveled through South America before boarding. The husband, 70, died April 11 — the first fatality — and his 69-year-old wife died April 26. A German woman passenger died May 2, The Korea Times reported.

A 69-year-old British male passenger was evacuated to South Africa on April 26. "This person is currently being treated in the intensive care unit in Johannesburg and is in a critical but stable condition," ship operator Oceanwide Expeditions said. Two crew members — one British, one Dutch — also developed acute respiratory symptoms, one of them severe. A fourth person reported a mild fever but is now asymptomatic.

"Hantaviruses circulate in rodents and can be deadly when transmitted to humans. In the Americas, the disease can cause severe respiratory illness," the WHO said. The typical incubation period is one to six weeks, complicating efforts to trace additional exposure. The Institut Pasteur in Dakar is conducting laboratory analysis of samples from the ship.

Passengers have been asked to isolate in their cabins while crew carry out disinfection measures on board. The South African health ministry confirmed the hospitalized British passenger's status through spokesperson Foster Mohale, according to The Korea Times.

WHO said the Hondius will head to Spain's Canary Islands for full disinfection and further epidemiological investigation. The outbreak is among the first documented clusters of hantavirus transmission at sea, health officials said.