Three people have died on a cruise ship in the Atlantic, the WHO said Sunday, one a confirmed case of hantavirus – an illness usually transmitted to humans from rodents.

The outbreak occurred on the MV Hondius, travelling from Ushuaia in Argentina to Cabo Verde, formerly known as Cape Verde.

“To date, one case of hantavirus infection has been laboratory confirmed, and there are five additional suspected cases,” the WHO told Agence France-Presse.

“Of the six affected individuals, three have died and one is currently in intensive care in South Africa.”

Earlier on Sunday, South Africa’s health ministry said there had been an outbreak of a “severe acute respiratory illness” which had killed at least two people, with a third in intensive care in Johannesburg.

The patient treated in Johannesburg tested positive for a hantavirus, a family of viruses that can cause haemorrhagic fever, South African spokesman Foster Mohale said.