San Francisco Frontiers - Hantavirus on the Hondius: what we know

Here is a look at what we know so far about those on board, the fatalities, the other symptomatic cases, the ship, its journey and the likely next steps:

- Who is on board? -

There are 147 people on board, among them 23 different nationalities, the World Health Organization said Tuesday.

A day earlier, the ship's Dutch operator Oceanwide Expeditions said there were 149 people on board, including a deceased German passenger.

It said there were 88 passengers from 15 countries, including 19 from Britain, 17 from the United States 13 from Spain and eight from the Netherlands.

There are 61 crew members, from 12 countries, including 38 from the Philippines, five from Ukraine, five from the Netherlands and four from Britain, it said.

- Three fatalities -

The fatalities include a Dutch couple who had travelled in South America before boarding the ship in Ushuaia, Argentina on April 1.

The husband fell ill on April 6 and died on April 11. His body was taken off the ship on April 24 on the British island Saint Helena.

His wife, feeling unwell, went ashore, deteriorated during an April 25 flight to Johannesburg -- which has a weekly airlink with Saint Helena -- and died in hospital on April 26, with hantavirus confirmed on May 4.

South African health ministry spokesperson Foster Mohale said the husband was 70 and the wife was 69.

A German woman passenger, who developed a fever on April 28, later presented with pneumonia and died on May 2. Her body remains on the ship.

- Four others fell ill -

A British male passenger fell ill on April 24 with signs of fever and pneumonia, and deteriorated on April 26. He was medically evacuated from Britain's Ascension Island to South Africa.

He is in intensive care, with hantavirus confirmed on May 2. Further tests are ongoing. Mohale said the passenger was 69. The WHO said it understood that the patient was "improving".

"This person is currently being treated in the intensive care unit in Johannesburg and is in a critical but stable condition," said Oceanwide Expeditions.

Two crew members, one British and one Dutch, have acute respiratory symptoms: one mild and one severe, the operator said.

The WHO said they were in a stable condition and tests were being sent to the Institut Pasteur in Dakar.

Medical evacuating the two -- likely to the Netherlands -- is the priority before moving the ship.

One further person reported mild fever but is now doing well and is asymptomatic, said the WHO, adding that there were currently no other symptomatic people on board.

- Hantavirus -

Hantaviruses circulate in rodents and can be deadly when transmitted to humans. In the Americas, the disease can cause severe respiratory illness.

Limited human-to-human transmission, among close contacts, has been documented for just one species: Andes virus, found in South America.

The WHO's working assumption, while awaiting test results, is that it is the Andes virus.

The typical incubation period for the virus is between one and six weeks, WHO epidemic prevention chief Maria Van Kerkhove said Tuesday -- suggesting infection among the Dutch couple before boarding.

There are no vaccines or specific medications for hantaviruses.

Last year, the wife of Oscar-winning actor Gene Hackman died of hantavirus, with the 95-year-old Hackman, who suffered from Alzheimer's disease, dying about a week later of natural causes.

- The MV Hondius -

The Dutch-flagged motor vessel was built in 2019 for polar expedition cruising. It is operated by Dutch cruise company Oceanwide Expeditions.

It was built for 170 passengers in 80 cabins, and can take 57 crew, 13 guides and one doctor.

The ship is 107.6 metres (353 feet) long and 17.6 metres wide, with a top speed of 15 knots.

- The journey -

After returning to Ushuaia in Argentina on March 31 following a trip to the Antarctic Peninsula, the cruise north through the Atlantic Ocean began on April 1, according to tracking site MarineTraffic.

After visiting islands including South Georgia (April 5-7) and Tristan da Cunha and nearby islands (April 13-16), the vessel called at Saint Helena (April 22-24)

It left Britain's Ascension Island on April 27.

The ship is now anchored off Praia, the capital of Cape Verde.

- What is happening on board? -

The WHO says passengers are being asked to isolate in their cabins while disinfection and other measures are being taken.

- Where might the ship go next? -

Cape Verde will not allow the ship to dock.

The WHO said the plan was for the ship to head north to Spain's Canary Islands for disinfection, risk assessment and a full epidemiological investigation, though Madrid said the health data from the ship would determine the next steps.

J.Peterson--SFF