Is This The Next COVID? Scientists Say No — But Here Is What Makes Andes Virus Unusual

Experts are unanimous that hantavirus will not cause a global pandemic. But the Andes strain at the center of this outbreak has properties that set it apart from every other known hantavirus — and scientists are still learning how it spreads.

Within hours of the WHO's public announcement about the MV Hondius outbreak, headlines began drawing comparisons to the early days of COVID-19: a novel pathogen, passengers dispersed across the globe, governments unsure who to allow ashore. 

But infectious disease experts are emphatic — hantavirus, even the rare Andes strain, is not COVID-19, and the mechanisms and history of the virus make a runaway global epidemic deeply unlikely.

What makes hantavirus dangerous: Hantavirus causes two distinct syndromes depending on the strain. The Andes virus, endemic to South America, causes Hantavirus Pulmonary Syndrome, a severe illness characterized by fever, gastrointestinal symptoms, rapid progression to pneumonia, acute respiratory distress syndrome, and shock. 

There is currently no approved vaccine and no specific antiviral treatment. Supportive hospital care, including mechanical ventilation, is the primary intervention. Historical fatality rates appear high, but experts note that mild or asymptomatic cases are likely underdiagnosed, meaning the true mortality rate may be considerably lower than published figures suggest.

"Transmission between people has been associated with close and prolonged contact, particularly among household members, intimate partners, and people providing medical care." — Dr. Tedros Adhanom Ghebreyesus, WHO

What makes the Andes strain unique: Among the more than 20 hantavirus strains known to infect humans, Andes is the only one documented to transmit between people, not just from rodents. A landmark 2019 outbreak in Argentina saw the virus spread among birthday party guests seated near one another, and then further at the deceased's wake. But this transmission requires close, sustained contact. It does not spread through casual or brief encounters.

Why this is not COVID-19: SARS-CoV-2 spreads efficiently between strangers in public settings through brief aerosol exposure. The Andes virus requires prolonged proximity — think household contact, not a subway ride. WHO has deployed 2,500 diagnostic kits from Argentina to laboratories in five countries, and has an expert physically aboard the Hondius conducting individual risk assessments. 

Dr. Stephen Kornfeld, a physician who was vacationing on the cruise and stepped in after the ship's doctor fell ill, told CNN that most passengers have had little or no contact with symptomatic individuals. "People on the boat have been in quarantine and isolation for three, four weeks," he said, adding that he expected most to be cleared relatively quickly upon docking.

WHO has said it expects more cases to be identified given the virus's one-to-six-week incubation window, but does not anticipate a large epidemic. The global public health risk, it maintains, remains low.