May 15, 2026

4 min read

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The hantavirus outbreak is reviving some of the worst COVID conspiracies

Hantavirus misinformation is spreading fast. COVID trauma and social media algorithms may be to blame

By Allison Parshall edited by Tanya Lewis

The first passengers from the MV Hondius depart for Tenerife Airport on May 10, 2026.

Anadolu/Getty Images

Since the first cases of hantavirus on the MV Hondius cruise ship were reported to the World Health Organization (WHO) on May 2, misinformation has rapidly flooded the Internet.

Much of it is familiar, echoing the conspiracies of the COVID pandemic, such as false claims about the drug ivermectin being known to effectively treat the infection and vaccines causing the outbreak. Hantavirus-related misinformation is “operating not like isolated rumors but more like a standing online ecosystem,” says Katrine Wallace, an epidemiologist at the University of Illinois Chicago. This kind of thinking is “ready to plug and play and rapidly attach itself to any kind of emerging health threat within hours,” she says.

But not all faulty information online is being spread in bad faith. Though public health officials have said the hantavirus outbreak poses a low risk to the public, fear is its own kind of contagion. “We’re still recovering from the collective trauma of going through COVID-19. People are still carrying that residual fear, exhaustion and distrust,” says Monica Wang, a public health researcher at Boston University, who specializes in health misinformation.

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In an environment where misinformation and fear are amplified by social media algorithms, it is hard to know what to listen to and what to tune out. The key strategy for staying informed is to focus on what we know and not fill in uncertainties with worst-case scenarios. The goal is “not to dismiss concern but to calibrate concern appropriately based on evidence,” Wang says.

Recalibrating Risk

The Andes type of hantavirus at the center of this outbreak isn’t new to scientists, but outbreaks like this one are scarce. The novelty of a rare disease outbreak can result in disproportionate media attention, Wang says. And understandably, “people are responding to this uncertainty and this unfamiliarity with the familiarity of what happens when we do have a pandemic,” she says.

Many of the lessons we learned from the COVID pandemic can, perhaps surprisingly, lead us astray if we try to apply them to the current hantavirus outbreak. The two situations are very different. First, this strain of hantavirus has been previously studied by epidemiologists; SARS-CoV-2, the virus that causes COVID, was entirely new to science. Second, Andes hantavirus is harder to spread from person to person and usually requires close contact to do so, although airborne spread can’t be ruled out. Third, the hantavirus outbreak is considered contained, unlike the early spread of COVID; the people most at risk of hantavirus are quarantining and being monitored. Fourth, epidemiologists suspect that hantavirus is most contagious when an infected person is showing symptoms, whereas SARS-CoV-2 can readily be transmitted by seemingly healthy people.

“It’s very hard [for people] to grasp the science of a new disease,” Wallace says. This helps to explain why COVID-era conspiracies and distrust in medical authorities have made a forceful comeback despite the differences between SARS-CoV-2 and hantavirus. When something about the current outbreak doesn’t seem to make sense, it’s easy to fall back on preexisting narratives to explain the discrepancy, such as the belief that authorities are withholding key information or that ivermectin is a cure-all. (There is no evidence that ivermectin, an antiparasitic medication, can treat hantavirus.) These false theories become especially powerful when they are amplified by people with large platforms, such as former congressional representative of Georgia Marjorie Taylor Greene and popular health influencers.

Threat Bias

The trauma of COVID can also highjack our reasoning by priming us to pay special attention to unfamiliar viral outbreaks and treat them as potentially devastating threats. “Humans aren’t wired for happiness. They’re wired for survival,” Wang says. If there is a potential threat in our environment, we will try to find out as much information as we can. “We pay attention when something triggers fear, surprise or disgust,” she says, “because we’re constantly seeking [to know] ‘Is my physical safety, or my social or emotional saf