The COVID-19 era and its tumultuous early weeks ensured that the global public may never look at virus outbreaks in quite the same way again.
And while scientists and experts are lining up to provide reassurance that the recent hantavirus outbreak has little chance of becoming an event that has a profound effect worldwide, for many there is a certain sense of deja vu.
A mysterious virus. A cruise ship. Quarantines. Conflicting information, all while public officials try to allay fears while also admitting there is still much they do not fully understand.
For all the apparent similarities, there is little to suggest that hantavirus is the start of another pandemic set to wreak havoc on a mass scale.
However, the outbreak has still become a stark reminder of how vulnerable the modern world remains to diseases that possess the ability to jump from animals to humans.
The Andes strain of hantavirus, a rare infection normally carried by wild rodents in parts of South America, is at the core of the current issue, with the outbreak having begun aboard the MV Hondius, a Dutch cruise ship that left Argentina last month. At least nine people have been infected and three have died, according to health authorities.
Unlike COVID-19, hantavirus does not spread easily through casual human interaction. That distinction is the single most important reason experts do not believe the current situation is likely to spiral into a global crisis.
Most hantavirus infections happen when people inhale microscopic particles from rodent urine, saliva or droppings. In the United States, infections have historically been linked to rural cabins, hiking shelters and wilderness areas where deer mice and other wild rodents are common. Fewer than 900 cases have been recorded in America over the past three decades.
The Andes strain, however, is unusual because it is the only hantavirus known to occasionally spread between people.
That is where comparisons to COVID begin to emerge — and where they quickly start to break apart.
COVID-19 was devastating because it was extraordinarily efficient at human transmission. People could spread it before they felt sick. It moved invisibly through crowds, airports, schools and offices. One infected person could unknowingly infect many others in a matter of hours.
Scientists studying the Andes virus say it simply does not behave that way.
Health officials, including acting Centers for Disease Control and Prevention director Jay Bhattacharya, have stressed that the virus appears to require close, sustained contact with someone already showing symptoms.
“You have to be in close contact with someone who has a lot of symptoms,” Bhattacharya told Fox News.
Even on the cruise ship itself, the numbers suggest the virus spreads poorly between humans. Roughly 150 passengers and crew members spent weeks in close quarters together, yet only a small number became infected.
Still, scientists caution against sounding too certain.
One reason the outbreak has drawn so much attention is because researchers still do not completely understand how the Andes virus spreads under every circumstance. In the largest documented outbreak, in Argentina in 2018 and 2019, investigators found evidence of what appeared to be “super-spreading events.” One infected man attended a birthday party while ill, and several attendees later became infected.
Some cases were even more puzzling. One person appeared to contract the virus after only briefly crossing paths with an infected individual. Another became sick after sharing a hospital room with a patient, despite no direct physical contact.
Those incidents have led some experts to suspect that airborne transmission may occasionally happen in rare situations.
“We have so little data that it’s really hard to say anything concrete or definitive,” said Kartik Chandran, a virologist at Albert Einstein College of Medicine, to the New York Times.
That uncertainty echoes one of the most frustrating aspects of the early COVID era: science unfolding in real time, with guidance evolving as evidence changes.
But there are also major differences that should reassure the public.
For one thing, hantavirus is not widespread globally. It does not circulate constantly in human populations the way COVID eventually did. It also appears far less contagious, even under ideal transmission conditions. Researchers point out that if the virus spread efficiently through the air like COVID, the cruise ship outbreak would likely involve dozens more infections already.
The real danger of hantavirus lies not in how easily it spreads, but in how severe it can be once someone becomes infected. The disease can cause rapid respiratory failure, and there are currently no approved vaccines or specific antiviral treatments.
The world is not reliving 2020. But the hantavirus outbreak is a reminder that the next global health scare may not look exactly like the last one — and that uncertainty itself is often what unsettles people most.