Speaking at a press conference in Madrid on Tuesday, Tedros warned that the situation could still change because of the virus’s long incubation period, adding that more cases may emerge in the coming weeks.
Three people have died after travelling on the ship, while seven confirmed cases have so far been recorded, including passengers from the United States and France.
The cruise vessel departed Spain’s Tenerife on Monday and is heading towards Rotterdam, where it is expected to arrive on May 17 for sanitation procedures.
The final group of evacuated passengers arrived in the Dutch city of Eindhoven on Tuesday after government-organised repatriation flights.
Dutch health authorities also placed 12 hospital workers in quarantine after possible exposure while treating one infected passenger in Nijmegen.
Hantaviruses are generally spread by rodents, though the Andes strain involved in this outbreak can also spread between humans. The WHO believes some passengers contracted the virus during the ship’s earlier journey in Argentina and other parts of South America.
Symptoms include fever, muscle pain, vomiting, diarrhoea, fatigue and breathing difficulties.
According to cruise operator Oceanwide Expeditions, 27 people remained aboard the vessel as of Monday evening, including crew members and medical staff from several countries.
Authorities in multiple countries, including the Netherlands, France, Britain and the United States, continue monitoring passengers and tracing contacts linked to the outbreak.
