'A perfect storm.'
That's how virologist Dr Jay Hooper describes the chain of events that likely lead to a deadly viral outbreak on a cruise ship now quarantined in the northern Atlantic Ocean with more than 140 passengers on board.
'It takes a very, very rare widow for all of these things to happen,' Dr Hooper told the Daily Mail in an exclusive interview.
That may have happened aboard the MV Hondius.
The Dutch-flagged expedition vessel was traveling from the southern-most tip of Argentina to the coast of West Africa in early April when the first passengers became ill.
Within a month, three people were dead and at least seven more were sick.
Reportedly, at least two Hondius passengers may have contracted the wild rodent-borne virus while birdwatching in the southern city of Ushuaia in mid-March, then they potentially brought the hantavirus on to the ship.
'If there was enough rodent waste that is aerosolized - gets into the air - you could be infected that way. You could probably be infected by eating food that's been contaminated by rodents,' Dr Hooper explained.
The Dutch-flagged MV Hondius was traveling from the southern-most tip of Argentina to the coast of West Africa in early April when the first passengers became ill. Within a month, three people were dead and at least seven more were sick
Reportedly, at least two Hondius passengers may have contracted the wild rodent-borne virus while birdwatching in the southern city of Ushuaia in mid-March, then they potentially brought the hantavirus on to the ship
It's a scenario that Dr Hooper, who has spent decades developing a hantavirus vaccine as the Deputy Chief of the Virology Division at the US Army Medical Research Institute of Infectious Diseases, has long feared.
'I've always thought that eco-tourists, those people who bushwhack around in places where this could happen, were at risk,' he explained. 'I'm kind of surprised that they ended up on a cruise ship and a bunch of other people were trapped there with them.'
According to Dr Hooper, hantavirus incubates for 30 to 50 days before people become symptomatic.
The virus kills 35 percent of those it infects and there is no standard treatment regimen for the disease, making it significantly more lethal than the Covid virus, which has killed more than seven million people worldwide since 2020.
The hantavirus 'infects endothelial cells, which are the lining of your blood vessels. They cause dysfunction so your blood vessels leak,' he says. 'It's horrific.'
Early symptoms range from fever to chills that quickly progress. In the late stages the lungs fill with fluid. If the infected cannot beat back the virus themselves, often a lung transplant is the only option.
Even more concerning, infected Hondius passengers and crew are confirmed to have contracted the rare 'Andes strain' of the disease, named for the Argentinian mountain range and endemic to the country, the only known strain of hantavirus that is transmissible between humans.
Passed between individuals by 'saliva' and 'other bodily fluid transmission,' Dr Hooper says that too would be uncommon, making the Hondius outbreak even more puzzling.
'It would have to be a perfect storm of the infected person in the small window when they are contagious, when they're shedding the virus and in close contact with somebody who gets a high enough dose to cause an infection.'
Hantavirus was named more than half a century ago when about 3,000 United Nations soldiers became sick with haemorrhagic fever while stationed along the Hantan River in Korea.
Since then, there have been hantavirus outbreaks in Europe, China, the US and Argentina, site of a super-spreader event in 2018 that sicken 34 and killed at least 11.
The virus kills 35 percent of those it infects and there is no standard treatment regimen for the disease, making it significantly more lethal than the Covid virus, which has killed more than seven million people worldwide since 2020 (Above, an infected patient being removed from a plane)
Dr Hooper spent decades developing a hantavirus vaccine as the Deputy Chief of the Virology Division at the US Army Medical Research Institute of Infectious Diseases
One thing Dr. Hooper can say with certainty is this the start of another Covid-like pandemic. 'I feel bad for the people [stuck] on that ship, but this is not like the early days of Covid.'
'It's not like Covid where transmission is airborne' and far easier to occur, Dr. Hooper says, who points out that Covid was often spread by asymptomatic individuals, who didn't realize they were infected.
Still, for the passengers on the MV Hondius, the coast is not yet entirely clear. Global health authorities, like the Centers for Disease Control (CDC) are going to take a conservative approach to monitoring and tracking passengers. Particularly as nearly two dozen Hondius passengers have returned to their home countries, including the US.
Dr Hooper hopes the unfolding health crisis comes with a silver lining: global attention.
As was the case of Covid, which went from outbreak to vaccine in less than two years, 'if there was a desire to rapidly move a vaccine forward, we could do it,' Dr. Hooper says. 'With industrial partners, we could do it [with a hantavirus vaccine].'