New Zealander on board hantavirus cruise ship

The Ministry of Foreign Affairs and Trade says it is aware of a New Zealander on board the MV Hondius cruise ship, which is experiencing a suspected deadly hantavirus outbreak.

A ministry spokesperson said it was in contact with the New Zealander, who had not requested consular assistance.

The ship, which was travelling from Argentina to the Canary Islands, is anchored off the coast of Cape Verde at present.

Dutch cruise company Oceanwide Expeditions said the number of confirmed cases connected to the outbreak on board had risen to two, with three deaths.

Passengers may have to isolate for weeks

Passengers on board a luxury cruise ship where three people have died from suspected hantavirus will need to isolate for close to two months, an infectious diseases expert says.

A Dutch couple and a German national have died, while a British national was evacuated from the ship and was in intensive care in South Africa, officials said.

A United Nations' health body says its working assumption is that the initial case of the couple, who joined the MV Hondius in Argentina, were infected off the ship, perhaps while doing activities such as bird watching, and that human-to-human transmission may have happened on board.

The ship is moored off Cape Verde in West Africa and the 149 passengers, including a New Zealander, are not allowed to go ashore.

Three more suspected cases are on board, one of whom has a mild fever.

They were expected to be evacuated in the coming hours in two air ambulances, Cape Verde's health ministry said on Tuesday night, Reuters reports.

One of the air ambulances is in the Atlantic archipelago located off West Africa and the second aircraft was expected to arrive shortly, the ministry said in a statement.

Massey University professor David Hayman told RNZ's Morning Report given the possibility of human-to-human transmission, passengers would likely need to be isolated for close to two months.

Hantaviruses were globally distributed, Hayman said. There was no vaccine or cure and there were various different types of it spread by rodents.

The hantavirus on the cruise ship was probably from South America, Hayman said, and would cause classic viral symptoms such as a fever and gastrointestinal illness. But with the South American type especially, it caused pulmonary and cardiovascular disease.

Normally people contracted hantavirus from contact with rodents or their excretion, Hayman said, and human-to-human transmission was very rare.

"It's going to make it quite difficult to manage as the World Health Organisation (WHO) recommends people should isolate for 45 days because there is a long incubation period... I feel for the passengers on the ship for this long period, not knowing what is going to happen."

On the ship, Hayman said it was likely the passengers were practising physical distancing and staying in their cabins.

"Because we don't have way or preventing hantavirus transmission in people - no vaccine - the only thing we can do are those physical distancing and hygiene protocols like we used in the early days of the Covid outbreak."

Hayman said all that could be done for treating hantavirus symptoms was trying generic antivirals and trying to maintain fluids and control fevers.

"Really, there's little you can do apart from supportive therapy."

- additional reporting by Reuters