The suspected hantavirus outbreak on the MV Hondius cruise ship, which has killed three people and sickened at least seven others, has two likely causes — and both are bad news for the 150 passengers on board, experts said.
The more likely scenario would be passengers contracting the virus from the feces, urine or saliva of infected rats or mice.
That’s the usual transmission vector, according to physician Zaid Fadul, a former Air Force flight surgeon — although the World Health Organization insisted Tuesday that no rodents have been found on the stranded liner.
But there’s one strain of the hantavirus that has an alarming exception — and the one that the WHO conceded “can’t be ruled out.”
“The Andes virus — that one specific subtype of the hantavirus — in Argentina, where they were, is the one that’s transmitted person-to-person,” Fadul said.
“And that’s where a lot of anxiety in this case is coming from.”
The Andes hantavirus strain carries a mortality rate of nearly 40%, meaning a worst-case scenario could spiral quickly in a confined environment such as the 80-cabin, 353-foot ship, the doc explained.
“And that’s why everyone is so scared,” he said.
The WHO confirmed Tuesday that it is the working theory, and that people may have been infected before boarding the ship.
“We do believe that there may be some human-to-human transmission that is happening among the really close contacts,” said Maria Van Kerkhove, the WHO’s epidemic and pandemic preparedness and prevention director.
The Dutch cruise liner had departed from Ushuaia, Argentina, on March 20 for its weeks-long “Atlantic Odyssey” voyage before the suspected hantavirus outbreak turned deadly.
Three passengers have since died — one confirmed from hantavirus — and another is fighting for his life, as the vessel with roughly 150 passengers remained stranded off West Africa on Monday.
Authorities were working to evacuate two additional sick passengers as well.
“If it is the Andes virus … you’ve got 150 people stuck on a cruise ship in close contact,” warned Fadul, head of the doctors group Bespoke Concierge.
Still, experts stress there’s no reason to panic.
“Prevention is the key,” Fadul said, adding that “good hand hygiene, staying away from people” and wearing a mask while around others could significantly reduce risk.
Health officials say a less terrifying explanation is far more likely: exposure to a rodent-borne strain, which is typically contracted by inhaling the virus from infected droppings.
Fadul doubts the source originated onboard.
“They could have picked it up anywhere — I don’t think it came from the ship,” he said, noting that hantavirus can take weeks to show symptoms after exposure.
Other experts agree that the outbreak probably came from vermin.
“The most likely situation is that people traveling from South America came in contact with infected rodents’ dropping in this part of the world,” said Giulia Gallo, a virus researcher with the Pirbright Institute in the UK.
“At the moment, we cannot be sure where the contact happened: It might have been during touristic activities in the region, or infected rodents might have been present on the ship,” Gallo said, the Science Media Centre reported.
The luxury cruise ship was refused permission to dock in the West African island nation of Cape Verde on Monday, after the boat had requested help from local health authorities following the latest death.
Authorities in the country, which has a population of 500,000, said the decision was made as a precaution, citing the “aim of protecting national public health.”
So far, no one has been allowed to disembark except those who need urgent medical care, according to Oceanwide Expeditions, the company operating the cruise ship.
The company said it was “managing a serious medical situation” and looking into whether the ship could sail to the Canary Islands, about 1,000 miles northeast, so that passengers could be screened and allowed to leave the vessel.
Gallo said the World Health Organization and other public health agencies will have to investigate the circumstances leading up to the three suspected hantavirus deaths on board the cruise ship.
“It would be necessary to identify any potential source of infection on the ship, and trace back the journey of the patients, to know if they visited American regions where hantaviruses are reported,” she told the outlet.
