When news emerged over the weekend that three people on board a cruise ship died following a suspected hantavirus outbreak, people across the world began to wonder: is this something we should be worried about?

Though haunted by the memories of Covid-19, which began as whispers of cases internationally before spreading worldwide and closing down large parts of society for about two years, by and large the general public do not need to be concerned about widespread cases of hantavirus, say experts.

Dr Eoghan de Barra, a senior lecturer at the Royal College of Surgeons in Ireland (RCSI) and consultant in infectious diseases at Beaumont Hospital, Dublin, said hantavirus outbreaks are still “very rare”.

“We’re okay. Overall, in a global picture, it’s a very rare thing,” he said, his comments chiming with both the World Health Organisation (WHO) and the HSE, which have described the risk as “low”.

What is hantavirus?

It’s a group of viruses that normally circulate in rodents.

De Barra said the “majority” of cases are typically found in Asia and Europe (except for Ireland, the UK, the Mediterranean coastal regions and the northernmost areas) and this variant has a case fatality rate of between 1 and 15 per cent.

In the Americas, particularly North America, the fatality rate can be much higher, at around 34 per cent, he added.

However, de Barra said Argentinian authorities have been “ringing a bell over this”, due to increasing cases reported there, as well as increased mortality rates in recent months.

What are the details of the outbreak?

The WHO said the seven confirmed or suspected cases comprise three people who have died, one ‌who ‌is ​critically ill and three with mild symptoms.

The three fatalities were a Dutch couple and a German national, while a British national was evacuated from the ship and is in intensive care in South Africa, officials said.

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Epidemiological investigations were under way to determine the source of the outbreak, the WHO said. Although uncommon, the WHO said limited human-to-human transmission of the Andes virus, a species of hantavirus found in Argentina and Chile, “has been reported in community settings involving close and prolonged contact”.

The ⁠Dutch couple, who were the first to die, had travelled in South ⁠America, including Argentina, before they boarded the cruise ​ship. It is suspected human transmission played a role in this outbreak.

Have there been high-profile cases before?

Yes, this is not the first time hantavirus has been in the news. In 2012, 10 tourists staying in tents in Yosemite national park were infected by the disease and three of them died.

Betsy Arakawa, wife of actor Gene Hackman, died in February 2025 at age 65 from hantavirus pulmonary syndrome.

But largely, cases of the virus tend to be confined to endemic regions.

What are the symptoms of infection?

According to the Health Protection Surveillance Centre (HPSC), there are three types of illness from the disease: haemorrhagic fever with renal syndrome (HFRS) and nephropathia epidemica (NE), which both affect the kidneys, and pulmonary syndrome, which affects the lungs (HPS).

Fever is the most common symptom in all three types of disease and lasts between three and seven days. Other symptoms vary depending on the diagnosis.

If you’re in an area where these viruses are common, what should you do?

De Barra said information is key when it comes to prevention, as there are currently no vaccinations available for the virus.

“You need to be informed about where you’re going. The simplest way to prevent infection is to wash your hands. Don’t share accommodation or beds with mice or rats,” he said. “For most people, it’s about being informed.”

The infectious diseases expert warned zoonoses – diseases that spread from animals to humans – are becoming more common in areas that typically would not have seen them, due to climate change, movement and other factors.