MADRID (AP) — More than two dozen people from at least 12 different countries left a cruise ship hit by a deadly hantavirus outbreak without contact tracing nearly two weeks after the first passenger died on board, the ship’s operator and Dutch officials said Thursday.

Health authorities on at least four continents are now tracking down and in some cases monitoring the cruise passengers who disembarked on April 24, and trying to trace others who may have come into contact with them since then.

World Health Organization officials say the risk to the wider public is low because hantavirus — usually spread by the inhalation of contaminated rodent droppings — isn’t easily transmitted between people.

“We believe this will be a limited outbreak if the public health measures are implemented and solidarity is shown across all countries,” said Dr. Abdirahman Mahamud, the WHO’s alert and response director.

The Dutch health ministry said Thursday that a flight attendant on a plane briefly boarded by an infected cruise passenger in South Africa was showing symptoms of hantavirus and would be tested in an isolation ward at a hospital in Amsterdam. The cruise passenger, also a Dutch woman, was too ill to fly and was taken off the plane in Johannesburg, where she died.