The first case of hantavirus infection on the cruise ship MV Hondius could not have occurred during the cruise, World Health Organization expert Anaïs Legand told AFP on Wednesday, UNN reports.
Details
The polar expedition vessel departed from Ushuaia, Argentina, on April 1 for a cruise across the Atlantic Ocean to Cape Verde, where it arrived on Sunday, with approximately 150 passengers and crew members on board.
The WHO, which received notification on Saturday of a rare but deadly hantavirus outbreak aboard the Hondius, determined that the first of the three deceased individuals was likely infected before boarding the vessel.
Of the eight confirmed and suspected hantavirus cases, a 70-year-old Dutch passenger was the first to fall ill. He began experiencing symptoms such as fever, headache, and mild diarrhea on April 6, developed respiratory distress on April 11, and died on board the same day, the WHO reported.
"The incubation period – the time between infection and the onset of symptoms – is between one and six weeks," but it is usually "closer to two to three weeks," Anaïs Legand, a WHO technical expert on viral hemorrhagic fevers, told AFP.
Therefore, the first case "could not have contracted the infection on the ship or on one of the islands" visited on the way to Cape Verde.
The man "quite clearly had contact with the virus before boarding the ship," a contact "certainly related to a rodent," she said.
Among the three deceased, the 69-year-old wife of the Dutchman tested positive for hantavirus. She was suffering from gastrointestinal symptoms when she accompanied her husband's remains ashore on the remote British territory of Saint Helena on April 24, and on April 25, she flew to Johannesburg, where she died the following day.
A third passenger, a German citizen, is also suspected to have died from hantavirus on the vessel on May 2.
Two other passengers who were on the ship and are being treated in hospitals in Johannesburg and Zurich also tested positive, while three people with suspected infections were evacuated from the ship on Wednesday and flown to the Netherlands. One German passenger was subsequently transported to Düsseldorf.
The vessel, which had been anchored off the Cape Verdean capital of Praia since Sunday, departed for Spain's Canary Islands on Wednesday.
Cruise ship with hantavirus leaves Cape Verde and heads for the Canaries07.05.26, 09:05
What is being said about the source of the outbreak
The Associated Press reports that the Argentine government's leading hypothesis is that the Dutch couple contracted the virus while birdwatching in Ushuaia, according to two investigators who spoke on condition of anonymity because they were not authorized to brief the media as the investigation is ongoing. Authorities are also tracing the Dutch tourists' steps on the forested slopes of Patagonia in southern Argentina, a hotspot for infection cases.
Hantavirus typically spreads from infected rodents, usually through urine, droppings, and saliva.
Human-to-human transmission has been documented for only one strain, the Andes virus, which was identified in both confirmed living patients.
The fatality rate for the Andes virus can reach 40 percent, which is "high," Legand told AFP.
"Regarding this virus, there is no evidence that the disease can be transmitted to someone before symptoms appear," she stated, noting that the highest risk of transmission is observed during the first week of illness.
According to initial data available to the WHO, the Andes virus can only be transmitted from one person to another in cases of close contact.
Legand cited the example of "saliva exchange" when couples kiss, emphasizing that investigations are ongoing to better understand the human-to-human transmission of the strain.
The WHO reports that before boarding the MV Hondius, the Dutch couple had traveled through South America, including Argentina.
According to data published Monday by the Argentine Ministry of Health, 42 new cases of hantavirus have been registered in the country this year. The ministry also reported a family cluster in the southern region of Chubut with suspected human-to-human transmission.
WHO representatives board the vessel
A day before the three people with suspected cases were evacuated from the Hondius on Wednesday, two WHO representatives joined those on the ship to work on impact assessment and help the crew properly inform and reassure passengers, Legand said.
The cruise ship is expected to arrive at a port in Tenerife in the Canary Islands "within three days," according to Spanish authorities.
"Discussions between the ship, national authorities, as well as medical authorities and the WHO are ongoing," WHO spokesperson Christian Lindmeier told AFP.
This is "to establish a protocol once the ship docks in the harbor, how best to treat these people on board, how quickly they can be removed from the ship, and how safely they can be removed," he said.
The bodies of the three deceased have not been moved, according to Legand. They remain on Saint Helena, in Johannesburg, and in a cold storage room on the MV Hondius.
Another evacuee from the cruise liner arrives in Europe
On Thursday, according to AFP, another sick passenger from the hantavirus-stricken cruise liner landed in Europe while the vessel was en route to the Spanish island.
On Thursday, a plane with the sick passenger on board landed in Amsterdam, a day after three people were evacuated from the ship, reported the vessel's operator, the Dutch company Oceanwide Expeditions.
"At this moment, there are no individuals with symptoms on board the vessel," the statement said.
Two people who returned to the UK from the ship were advised to self-isolate, the UK Health Security Agency reported, adding that they are asymptomatic and insisting that the risk to the public is "very low."
People believed to have contracted the virus have been sent for treatment or isolation in the UK, Germany, the Netherlands, Switzerland, and South Africa.
A flight attendant for the Dutch carrier KLM is reportedly undergoing testing for the virus after possible contact with an infected person during a flight.
Dutch airline KLM reported on Thursday that one of its flight attendants was being tested for hantavirus after showing mild symptoms.
The day before, the airline reported that one of the people who died from the virus had been on its flight from Johannesburg to the Netherlands on April 25 for a "short time" but was removed before takeoff.
The World Health Organization downplayed fears of a broader global outbreak of the virus, with its head Tedros Adhanom Ghebreyesus telling AFP on Wednesday that "the risk to the rest of the world is low."
The U.S. Centers for Disease Control and Prevention (CDC) echoed this sentiment, stating: "Currently, the risk to the American public is extremely low."
Meanwhile, officials in Argentina said they plan to conduct testing on rodents in the coastal city of Ushuaia, from where the ship sailed on April 1.
The Dutchman, who boarded in Ushuaia with his wife, died on board the ship on April 11 without raising an alarm.
The ship's captain announced the death to passengers as being from "natural causes," said Ruhi Çenet, a 35-year-old Turkish travel vlogger who was on board the ship.
The man's body was removed from the ship on April 24 at Saint Helena, an island in the South Atlantic.
The alarm was raised by the deceased's wife, who left the ship to accompany his body to South Africa and died there 15 days later after also falling ill; hantavirus was confirmed as the cause of illness on May 4.
According to Argentine officials, the couple visited Chile, Uruguay, and Argentina before the cruise.
The Dutch woman flew on a commercial flight from Saint Helena to Johannesburg while she had symptoms.
Officials have been trying to locate people on that flight, which, according to South African carrier Airlink, had 82 passengers and six crew members on board.
Dozens of passengers disembarked from the cruise liner on an island in the South Atlantic
Another 29 passengers from the liner disembarked at Saint Helena, the ship's operator reported. As noted by AP, the company said on Thursday that 29 passengers left the ship at Saint Helena, while the Dutch Ministry of Foreign Affairs put the number at approximately 40. Previously, the company had not confirmed that dozens more people had left the ship at that time.
"All these guests have been contacted by Oceanwide Expeditions. We are working to establish information on all passengers and crew members who embarked and disembarked at various stops of the Hondius since March 20," the company's statement said.
According to Oceanwide Expeditions, the people who left the ship to return to their home countries were of at least 12 different nationalities. It was also noted that there were two other people whose nationality is unknown.
As AFP points out, discrepancies remain regarding the stated number of people on board the ship.
According to the operator, when the ship dropped anchor off Cape Verde, there were 149 people on board, including 88 passengers. But when the cruise liner departed from Argentina on April 1, there were 114 guests and dozens of crew members on board, the operator reported on Thursday.