The World Health Organization has officially declared an end to the hantavirus outbreak linked to the Dutch-flagged polar expedition cruise ship MV Hondius, after the last identified contact of an exposed passenger completed quarantine and tested negative for the virus. "No further cases have been reported since the 25th of May. Therefore, WHO considers the hantavirus outbreak over," WHO Director-General Tedros Adhanom Ghebreyesus announced on Thursday.

The outbreak, which infected 13 people and killed three, centred on the rare Andes strain of hantavirus, a variant that circulates primarily in Argentina and Chile and is notable for being the only known hantavirus capable of spreading through close, prolonged human-to-human contact. The Hondius departed from Ushuaia — the southernmost city in the world, located at the tip of Argentina — on 1 April on a 46-day voyage that took passengers to remote South Atlantic destinations including the Falkland Islands and the isolated volcanic island of Tristan da Cunha, before heading north to Tenerife in Spain's Canary Islands. The ship ultimately docked in Rotterdam, the Netherlands, on 18 May, where it underwent cleaning and disinfection before being cleared to sail again on 30 May.

Among those who died were a Dutch couple: a 69-year-old man who passed away aboard the ship on 11 April, and his wife, who died later in a hospital in Johannesburg, South Africa. A 65-year-old German woman also died aboard the vessel on 2 May. According to Argentine officials, the couple is believed to have contracted the virus during a birdwatching excursion in Ushuaia before boarding. In total, health authorities across 33 countries and territories tracked more than 650 contacts of infected individuals.

Hantavirus spreads primarily through rodents, with people infected via contact with rats, mice, or their urine, droppings, and saliva. The virus can become airborne when infested areas are cleaned. Symptoms typically appear between one and eight weeks after exposure and include fever, headache, muscle aches, and gastrointestinal problems. In severe cases, the illness can rapidly progress to respiratory failure and fluid accumulation in the lungs. There are currently no approved vaccines or targeted antiviral treatments; care remains largely supportive.

The scale of the international response — spanning three dozen countries — underlines the logistical complexity of containing an outbreak aboard a vessel that crossed multiple ocean zones. Tedros said the WHO is now coordinating a study involving 21 countries to better understand how the disease develops, with the aim of supporting the eventual development of diagnostics, therapeutics, and vaccines.