Argentine Officials Probe Bird-Watching Tour as Source of Hantavirus Outbreak on Cruise Ship

A bird-watching tour in Ushuaia, Argentina, where hantavirus cases had never been recorded, lies at the heart of an investigation into an outbreak on a cruise ship. Argentine officials are checking if a Dutch couple picked up the virus from rodents at a landfill during the tour and carried it aboard the MV Hondius.

Two Argentine officials investigating the outbreak told the Associated Press on Wednesday that exposure to rodents at the landfill represents the leading theory. The couple contracted hantavirus before boarding the Dutch-flagged ship.

Hantavirus typically spreads through inhaling contaminated rodent droppings. The World Health Organization says human-to-human transmission is uncommon but possible.

Authorities had previously noted that Ushuaia and the surrounding Tierra del Fuego province reported no prior hantavirus cases.

The outbreak on the MV Hondius has killed three passengers and sickened others. Contact tracing targets passengers who disembarked in Europe and Africa.

Tests in Switzerland, South Africa and Senegal confirmed the Andes strain, authorities said. The WHO states this variant, found mainly in Argentina and Chile, can spread through close contact, though rarely.

Swiss officials reported a man who returned from the cruise developed symptoms, sought treatment and tested positive for the Andes strain. He was isolated immediately.

WHO Director-General Tedros Adhanom Ghebreyesus said Wednesday that three suspected cases were evacuated from the ship and are headed to the Netherlands for treatment.

"At this stage, the overall public health risk remains low," Tedros said.