Can Hantavirus Become Another Global Pandemic? Here's What Virologists Say

A 40% Fatality Rate — But Why Experts Are Not Panicking

The hantavirus outbreak aboard the MV Hondius has raised an uncomfortable question: could this become the next global pandemic? The numbers are stark — the Andes strain of hantavirus, the variant involved in the ship outbreak, carries a fatality rate of approximately 40%, against an average of around 38% for hantaviruses overall. There is no specific antiviral treatment; doctors can only offer supportive care: oxygen therapy, fluid management, blood pressure support, and mechanical ventilation.

Yet the World Health Organisation officially assesses the risk of global spread as "low" — and virologists broadly agree. The reason comes down to a fundamental principle of infectious disease: deadlier diseases tend to spread less readily.

Why Severity Limits Spread

COVID-19 spread so effectively in part because a large proportion of infected people had mild or no symptoms. They moved around, went to work, travelled — unknowingly transmitting the virus for days before any illness was apparent. Hantavirus does the opposite: it causes severe illness rapidly, leaving patients bedridden and severely ill within a short window. That drastically reduces the opportunities for further transmission.

The virus also causes fluid buildup in the lungs in serious cases, meaning those most infectious are also those least able to move around and expose others.

Human-to-Human Transmission — What It Actually Means

Most hantavirus strains do not spread between people at all — transmission is typically through inhalation of, or contact with, infected rodent faeces, urine, or saliva. The Andes strain is the exception: it is the only hantavirus strain known to allow person-to-person spread.

However, the threshold for that transmission is high. Maria Van Kerkhove, WHO Director of Epidemic and Pandemic Management, explained that "close contact" typically refers to situations such as sharing a cabin or bunk room on board the ship — not the kind of casual contact that allows respiratory viruses to spread through a city.

No Treatment — Supportive Care Only

There is currently no approved antiviral drug specifically targeting hantavirus. Treatment is entirely supportive: keeping patients oxygenated, managing fluid levels, maintaining blood pressure, and providing ventilation where necessary. This underlines the importance of early detection and hospital admission for anyone suspected of exposure.

What the Experts Conclude

The combination of factors — high lethality, rapid severe illness, limited transmission routes, and a low transmission rate compared to respiratory viruses like COVID-19 — means hantavirus is extremely unlikely to generate a self-sustaining global outbreak. The WHO's "low risk" assessment reflects the current scientific consensus.

That does not make it any less serious for those directly affected. But for the wider public in Spain and across Europe, the evidence supports the message from health authorities: monitor the situation, follow contact tracing guidance if you were on the MV Hondius, and seek medical attention immediately if you develop respiratory symptoms — but the risk to the general population remains very low.

This article is based on reporting from The Olive Press, published May 7, 2026.