LONDON — A hantavirus outbreak linked to a luxury cruise ship in the Atlantic is challenging global health authorities to refine how they communicate about infectious diseases in a post-COVID world, as officials work to balance transparency, reassurance, and the need to counter misinformation.

The outbreak, involving the Andes strain of hantavirus aboard the MV Hondius, has resulted in three deaths among 11 confirmed cases, with dozens of additional passengers under monitoring across roughly 20 countries. While the virus is not new and is not considered likely to trigger a pandemic, its sudden appearance in a high-profile maritime setting has triggered public anxiety and online comparisons to the COVID-19 pandemic.

Rodent-borne hantavirus is known to circulate in parts of South America, particularly Argentina and Chile, and health authorities say the current strain shows no significant genetic variation from previously identified versions. Unlike COVID-19, experts emphasize that established containment measures exist and human-to-human transmission remains rare.

Still, the cruise ship setting has amplified public concern, recalling early-pandemic images of quarantined vessels such as the Diamond Princess in 2020, where infections spread widely and 14 people died.

Health officials say the challenge now is not only epidemiological but also communicational.

In Illinois, state health authorities attempted a conversational approach in a recent public advisory, urging residents to read full information before reacting to avoid unnecessary panic. European and international agencies have similarly increased efforts to provide rapid updates while addressing uncertainties.

“We spend half of our time discussing how we will communicate,” said Gianfranco Spiteri, emergencies lead at the European Centre for Disease Prevention and Control. He said agencies are attempting to apply lessons learned during COVID-19, when inconsistent messaging, delayed responses, and politicization contributed to public mistrust.

A study of European Union countries found declining confidence in public health institutions in most member states between 2020 and 2022, underscoring the lingering impact of the pandemic on trust in official guidance.

Officials involved in the hantavirus response say they are now more focused on clarity, empathy, and speed in addressing public concerns, while also acknowledging gaps in scientific certainty.

“There are people who say we are overdoing it, and on the other extreme, that we’re not doing enough,” Spiteri said. “We always base our messages on the evidence we have.”

Despite those efforts, misinformation has circulated widely online, including false claims comparing hantavirus to COVID-19, promoting unproven treatments such as ivermectin, vitamin D, and zinc, and suggesting conspiracy theories linking the outbreak to vaccines or deliberate fabrication.

Experts say such narratives highlight the ongoing challenge of managing information during health crises.

“We have kind of lost perspective,” said Gustavo Palacios, a hantavirus specialist at the Icahn School of Medicine at Mount Sinai.

He said outbreaks can be serious public health events without necessarily escalating into global pandemics, a distinction he believes is often lost in public discourse shaped by recent pandemic memory.

Communication researchers argue that preparedness must include not only medical readiness but also public resilience against misinformation.

Sander van der Linden, a psychologist at the University of Cambridge, said authorities should consider proactive education strategies that help people interpret conspiracy theories and misinformation before outbreaks occur.

“We need to do more preparatory work to create resilience in the population,” he said.

The World Health Organization has moved quickly to address concerns, holding briefings, issuing alerts, and responding to misinformation through social media channels. WHO Director-General Dr. Tedros Adhanom Ghebreyesus also issued an open letter to residents of Tenerife, where the cruise ship docked, stressing that the situation is not comparable to COVID-19 and that the public health risk remains low.

The U.S. Centers for Disease Control and Prevention initially issued guidance several days after the outbreak was reported but has since increased its communications.

Experts say the episode underscores a broader lesson from the pandemic era: the timing and tone of public messaging can significantly influence public perception.

“One of the things this is teaching us is a lesson we should have learned from COVID: what we say is really important,” said Michael Osterholm, an infectious disease expert at the University of Minnesota.

Public reaction has been shaped in part by the cruise ship setting, which has revived memories of early COVID-19 outbreaks at sea, particularly the Diamond Princess incident in Japan.

“There’s an emotional reaction that is stirring people,” said Krutika Kuppalli, an infectious disease physician at the University of Texas Southwestern Medical Center.

For some, the response on the ground has reinforced a sense of urgency. In Tenerife, where passengers began disembarking under strict infection control protocols, residents observed the coordinated international response with concern but also recognition of its purpose.

“It gave me the impression that this isn’t just the flu,” said Laura Millán, 40. “Otherwise all these people wouldn’t be coming.”