In the last week, fears of an impending pandemic have spread on social media after news emerged that three people, including two who were confirmed to have had hantavirus, died aboard a cruise ship sailing the Atlantic Ocean.

The outbreak, centred on the Dutch expedition vessel MV Hondius, has set off a global contact-tracing emergency, with health authorities in several countries scrambling to locate passengers who had already disembarked and dispersed across the world before the virus was identified. The ship docked at the port of Granadilla in Spain before dawn on Sunday, May 10, a month after the first of its passenger died.

WHO Technical note for the disembarkation and onward management of passengers and crew in the context of an Andes virus-associated cluster MV Hondius cruise ship. Read here: https://t.co/YB7jgI3t1x
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Management of contacts of Andes virus (ANDV) cases from the MV Hondius cruise…

— World Health Organization (WHO) (@WHO) May 10, 2026

Hantavirus is not new. But the specific strain involved is what has health officials worried and social media in a panic. Here is what we know so far.

What is Hantavirus?

It is a virus carried by rodents: rats, mice, that sort of thing. You catch it not from a bite necessarily, but from coming into contact with an infected animal’s urine, droppings or saliva. Think: cleaning out an old storage room, working on a farm, or sleeping somewhere heavily infested with rodents. It is not new. Scientists have known about it for decades. Most years it causes quiet, scattered cases in rural South America, Europe and Asia — the kind of thing that never makes global headlines.

Until now.

What makes this outbreak different?

The strain on this ship is called the Andes virus. It is the only known strain of Hantavirus that can spread from one person to another. That is the detail that changed everything and has triggered fears of a mass outbreak with the horror and chaos of COVID-19 still fresh on people’s minds. Every other strain of this virus stops at the rodent-to-human jump. The Andes virus does not always stop there.

To be clear, human-to-human transmission has only been documented through close, prolonged contact: think sharing a bed or living in the same house as someone who is sick, especially in the early days of their illness. You are not catching this from someone coughing next to you on the bus, according to the World Health Organization (WHO).

But on a cruise ship? Where people share cabins, dining rooms and corridors for weeks? That is a different calculation, which might explain how three confirmed cases were found on the cruise ship.

How deadly is it?

Very. The Andes strain kills between 35 and 50 percent of severe cases, because the virus tends to affect organs like the lungs and kidneys that are critical for survival. For comparison, COVID-19’s global fatality rate averaged well below one percent. There is no antiviral drug that treats Hantavirus. No widely available vaccine exists. Doctors essentially keep patients alive and hope their bodies fight it off.

Is this going to be another pandemic?

Almost certainly not. The WHO and other health experts say the risk to the general public is extremely low. Experts point out that the Andes strain has never triggered a widespread outbreak, it has only ever spread between people in very close contact. It does not travel through the air the way COVID did.

Hantaviruses are zoonotic viruses that naturally infect rodents and can occasionally spread to people.

Here’s what you need to know about #hantavirus: What they are, how they spread, the symptoms, and how to prevent infection pic.twitter.com/pduUjlwl2j

— World Health Organization (WHO) (@WHO) May 8, 2026

What is genuinely new here is the scale of the setting. Scientists have never before seen possible human-to-human transmission of this virus play out across a ship full of people from 23 countries simultaneously. That is why they are watching this so carefully.

Are there Hantavirus cases in Nigeria?

No. In a public health advisory posted on Saturday, May 9, the Nigeria Centre for Disease Control and Prevention (NCDC) said there was NO confirmed case of Hantavirus in Nigeria, echoing other health agencies that the overall risk to the public remains low.

🚨 PUBLIC HEALTH ADVISORY 🚨

The Nigeria Centre for Disease Control and Prevention (NCDC) has released a Public Health Advisory to address the recent reports of a Hantavirus cluster linked to international cruise ship travel involving multiple countries.

At this time, there is…

— NCDC (@NCDCgov) May 9, 2026

The centre said it was actively monitoring the situation and strengthening surveillance for emerging infectious diseases.