Three people have died following a suspected hantavirus outbreak on a cruise ship in the Atlantic Ocean.
The World Health Organization reported one confirmed case and five suspected cases on board the MV Hondius.
The vessel was travelling from Argentina to Cape Verde.
A 69-year-old British national is in intensive care in Johannesburg. Local officials say he has the virus.
Hantavirus spreads mainly through contact with rodents. It can cause severe respiratory illness.
The ship is operated by Oceanwide Expeditions. The company confirmed the three passenger deaths and described the situation as serious.
The cruise departed from Ushuaia on March 20. It arrived off Praia on May 4.
South African health officials say about 150 tourists were on board.
A Dutch man, aged 70, died after developing fever, headache and abdominal pain. He died on arrival at Saint Helena.
A 69-year-old Dutch woman also fell ill. She was flown to South Africa, where she later died in hospital.
A third Dutch passenger also died. Authorities are arranging the repatriation of the body.
Two crew members also need urgent medical care. However, authorities in Cape Verde have not yet approved their disembarkation.
Oceanwide Expeditions said it is working closely with local health officials to manage the situation.
Experts warn that hantavirus symptoms can take weeks to appear. This raises concern that more cases could emerge.
The UK government says it is monitoring the situation and is ready to assist its citizens.
