Hantavirus outbreak on cruise ship raises questions about transmission

A hantavirus outbreak on a cruise ship that left Argentina last month has so far infected five people and caused three deaths, according to reports from Danish broadcaster DR. While the situation may recall the early days of the coronavirus pandemic, experts say the risk of hantavirus spreading in Denmark remains very low.

Hantavirus is carried by rodents such as rats and mice, which do not fall ill from the virus themselves. Humans typically become infected by inhaling dust contaminated with rodent urine or droppings, particularly in poorly ventilated areas like attics or storage spaces. The World Health Organization (WHO) warns that sweeping or disturbing areas where rodents have been active can increase infection risk.

Bites from infected rodents can also transmit the virus, though this is less common. Unlike coronaviruses or influenza, most hantavirus strains—including those found in Europe and Asia—do not spread between humans. However, the variant detected on the MV Hondius cruise ship appears to be an exception, with limited person-to-person transmission observed among close contacts, such as household members or partners, primarily in the early stages of illness.

The hantavirus strains present in Denmark pose minimal risk of human-to-human transmission and have a low fatality rate, according to the Statens Serum Institut and European health authorities.