The World Health Organisation (WHO) said on Friday that the risk posed to the public by a deadly hantavirus strain linked to a cruise ship outbreak remained minimal, stressing that the virus spreads only through “very close contact”.

“This is a dangerous virus, but only to the person who’s really infected, and the risk to the general population remains absolutely low,” WHO spokesman, Christian Lindmeier, told a press briefing in Geneva.

He pointed out that even people who had stayed in the same cabins aboard the affected MV Hondius cruise ship “don’t seem to be both infected in some cases”.

The health body had said on Thursday that more hantavirus cases could emerge after the disease killed three passengers from the vessel, although it expected the outbreak to remain limited if precautionary measures were observed.

Another ill passenger from the MV Hondius arrived in Europe earlier on Friday as the vessel headed towards Spain’s Canary Islands, while health officials intensified efforts to trace the outbreak of the potentially deadly human-to-human strain.

The fate of the Hondius sparked international concern after three people travelling on the ship died. However, health authorities have downplayed fears of a wider global outbreak from the rodent-borne virus, which is considered less contagious than COVID-19.

US President Donald Trump said on Thursday that he had been briefed on the situation.

“It’s very much, we hope, under control,” Trump told reporters.

“It was the ship — and I think we’re going to make a full report about it tomorrow. We have a lot of great people studying it… It should be fine, we hope,” he added.

A Dutch couple who had travelled around South America before boarding the ship in Ushuaia, Argentina, on April 1 were the first fatalities linked to the outbreak.

Argentine health authorities said on Thursday that they had yet to determine where the outbreak began.

“With the information provided so far by the countries involved and participating national agencies, it is not possible to confirm the origin of the infection,” the country’s health ministry said after a meeting with authorities from all 24 Argentine provinces.

WHO Director-General, Dr. Tedros Adhanom Ghebreyesus, told journalists in Geneva that five confirmed and three suspected cases had been reported overall, including the three deaths.

“Given the incubation period of the Andes virus, which can be up to six weeks, it’s possible that more cases may be reported,” he said, referring to the rare strain detected aboard the Hondius, which can be transmitted between humans.

The Leiden University Medical Centre in the Netherlands later announced that another patient had tested positive.

However, WHO’s emergency alert and response director, Abdi Rahman Mahamud, said he believed the situation would remain “a limited outbreak” if “public health measures are implemented and solidarity shown across all countries”.

People believed or known to have contracted the virus are being treated or isolating in Britain, Germany, the Netherlands, Switzerland, and South Africa.

Hantavirus is a rare respiratory disease usually spread by infected rodents. It can cause respiratory and cardiac distress, as well as haemorrhagic fevers. There is currently no vaccine or known cure.

Health officials believe one passenger contracted the virus before boarding the ship in Argentina and subsequently infected others on board as it sailed across the Atlantic.

Authorities in Argentina said they planned to test rodents in the coastal city of Ushuaia, where the ship departed on April 1.

Three evacuees were removed from the ship on Wednesday when it anchored off Cape Verde, while a fourth passenger arrived in Amsterdam on Thursday, according to the vessel’s operator, Netherlands-based Oceanwide Expeditions.

The company said there were no symptomatic individuals currently on board as the ship sailed towards the Spanish island of Tenerife, where it is expected to arrive on Sunday.

YouTuber Kasem Ibn Hattuta, a passenger aboard the Hondius, posted a video describing how he learned of the first death around 12 days into the voyage.

“Most people on board are reacting very calmly to the situation, unlike what is being reported in the media,” Hattuta said.

“Today was supposed to be the last day of our 35-day voyage across the Atlantic Ocean. But it is clear that our journey will not end here,” he added, referring to Cape Verde’s refusal to allow the Hondius to dock.

A Dutch man who boarded the vessel in Ushuaia with his wife died aboard the ship on April 11.

The man’s body was removed from the ship on April 24 in Saint Helena, a South Atlantic island where 29 other passengers also disembarked, according to the ship’s operator.

The company said it was working to trace all passengers and crew members who had boarded or left the vessel since March 20.

Tedros said the WHO had informed 12 countries whose nationals disembarked from the cruise ship in Saint Helena.

The Saint Helena government said that “more than 95 per cent” of the population had no close contact with the ship’s passengers or crew, nor boarded the vessel, and therefore remained “at an extremely low risk of infection”.

The deceased man’s wife, who left the ship to accompany his body to South Africa, died there 15 days later after also falling ill. Hantavirus was confirmed as the cause of death on May 4.

Authorities in Buenos Aires said the couple had visited Chile and Uruguay, in addition to Argentina.

Chile’s health ministry stated that the couple were not infected in that country because they travelled there during “a period that does not correspond to the incubation time”.

According to the WHO, the incubation period for hantavirus can last up to six weeks.

The Dutch woman flew on a commercial flight from Saint Helena to Johannesburg while exhibiting symptoms.

Officials are currently tracing passengers aboard the flight, which South African carrier Airlink said carried 82 passengers and six crew members.

A German passenger also died on May 2, and her body remains aboard the ship.