Scientists at the Geneva University Hospital, HUG, a collaborating centre of the World Health Organisation, have identified the hantavirus strain linked to three deaths aboard a cruise ship in the Atlantic Ocean.

The strain has been confirmed as the Andes variant, the only known hantavirus capable of human-to-human transmission.

A statement from HUG said the identification followed analysis of a sample taken from a passenger on the MV Hondius, who tested positive via PCR at the Centre national de référence pour les infections virales émergentes (CRIVE), the hospital’s virology laboratory, on 5 May 2026.

Dr Manuel Schibler, head of the HUG virology laboratory, said the finding is significant because the Andes strain remains the only hantavirus with documented person-to-person spread.

The results, he said, have already been shared with Switzerland’s Federal Office of Public Health and the WHO.