Hantavirus outbreak tests post-Covid-19 health communication playbook

LONDON – A rodent-borne virus with a scary name. A mid-ocean cruise ship in quarantine. Several people dead and more falling sick.

It is no wonder that an outbreak of the Andes strain of hantavirus on a luxury liner in the Atlantic has revived some Covid-19-era trauma and panic online.

That has presented a dilemma to health officials: how to communicate quickly and clearly about a virus which is not new and unlikely to cause a pandemic but where knowledge gaps remain – without inadvertently fomenting fear.

“Hantavirus thread incoming,” posted the health department of Illinois state in the US earlier this week about a risk-free case unrelated to the MV Hondius cruise ship outbreak.

“But you have to promise to read this whole thread before panic-texting your group chat. Deal?”

In interviews with Reuters, half a dozen health officials said they were trying to learn from mistakes around the Covid-19 pandemic, providing information on hantavirus with more empathy while addressing uncertainties and tackling falsehoods.

“We spend half of our time discussing how we will communicate,” said Dr Gianfranco Spiteri, emergencies lead at the European Union’s (EU’s) European Centre for Disease Prevention and Control.

During the coronavirus pandemic, many governments were slow to react or in denial, public messaging was sometimes confusing and contradictory, restrictions and vaccine rollouts were applied differently round the world, and misinformation and politicisation proliferated.

That helped fuel modern mistrust of institutions.

For example, faith in public health institutions declined in 20 of 27 EU countries between 2020 and 2022, one study showed.

Juggling communication

Dr Spiteri and others at the forefront of the hantavirus response spoke about the need to balance explanations of why it is a serious global health event with reassurances that risks to the public are low and honesty over the open questions about a virus that has rarely spread among humans before.

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

From a look at social media, their efforts are still a work in progress, with many people needlessly fretting about a return to lockdowns, social distancing and masks.

Said Professor Gustavo Palacios at Icahn School of Medicine at Mount Sinai in the US: “We have kind of lost perspective.”

An outbreak can be a major public health event deserving attention and action but without becoming a pandemic, he noted.

Some posts online falsely present hantavirus as a bigger existential threat than Covid-19, or promote protections like the ivermectin anti-parasite drug, vitamin D and zinc without scientific evidence. False conspiracy theories are popping up too – that it is a side effect of the Pfizer vaccine or a hoax to boost pharmaceutical profits.

Professor Sander van der Linden of psychology at England’s University of Cambridge and misinformation expert said the public need more support in how to interpret information, including potentially showing them conspiracy theories they may face in the event of an outbreak.

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

As of May 14, there had been three deaths from 11 reported hantavirus cases in the outbreak, all people who had been on board the Hondius. Dozens of other passengers are being monitored as they return to around 20 countries.

Unlike Covid-19, there are established measures to control hantavirus’ spread, officials said. The strain has circulated in parts of Argentina and Chile for decades and the ship samples show no meaningful variation from that virus.

“I’m definitely seeing improvements,” said Ms Gabby Stern, former head of communication at the World Health Organization (WHO) until September 2025, referring particularly to sharing what you know when you know it.

“It seems like the public health community has absorbed crucial lessons, although not all of them.”

‘Emotional reaction’ to cruise ship

The WHO was quick to reassure the public, holding regular press conferences, issuing alerts and tackling misinformation in social media Q&As since the outbreak was disclosed on May 3.

WHO chief Dr Tedros Adhanom Ghebreyesus even took the unusual step of issuing an open letter to the people of Tenerife, where the Hondius docked on May 10.

“But I need you to hear me clearly: This is not another Covid-19,” he wrote. “The current public health risk from hantavirus remains low. My colleagues and I have said this unequivocally, and I will say it again to you now.”

Some started more slowly. In the US, the Centres for Disease Control and Prevention put out its first information on May 8, five days after the news broke, but has since increased the pace of communication.

“One of the things this is teaching us is a lesson we should have learnt from Covid-19: What we say is really important,” said Professor Michael Osterholm, an infectious diseases expert at the University of Minnesota.

The cruise ship hantavirus narrative has not helped, echoing the infamous outbreak on the Diamond Princess docked off Japan early in the Covid-19 pandemic in 2020 where 14 people died and nearly a quarter of the 3,000 passengers and crew became infected.

“The whole cruise ship thing… is a very significant memory from the beginning of Covid-19,” said Associate Professor Krutika Kuppalli of medicine at the University of Texas Southwestern Medical Centre.

“There’s an emotional reaction that is stirring people.”

The resemblance was not lost on Ms Laura Millan, 40, in Tenerife, as passengers began to disembark at the beginning of this week under strict infection-control measures.

Seeing WHO boss Dr Tedros arrive on the island with Spanish officials to help oversee the hantavirus response took her back.

“It gave me the impression that this isn’t just the flu – otherwise all these people wouldn’t be coming,” she said at a playground, adding that overall she understood their involvement helped ensure the right measures were in place. REUTERS