May 7 (UPI) -- Public health officials conducted contract tracing across the globe Thursday in response to cruise ship operator Oceanwide Expeditions' announcement that 29 people disembarked the vessel after the start of a hantavirus outbreak.

The outbreak on the MV Hondius has killed three people.

Two passengers on the cruise ship that had an outbreak of hantavirus returned to the U.S. before the disease was identified, but they're not showing any symptoms.

Oceanwide Expeditions says it acted according to proper protocol after the death of a 69-year-old Dutch passenger aboard the Hondius. The company responded after an online video surfaced showing the ship’s captain describing the incident as a natural death. Details have emerged about ongoing efforts to contain the infection, including KLM’s decision-making after a critically ill cruise passenger boarded a KLM aircraft, and the confirmation of another cruise passenger with hantavirus being treated in Leiden.

Three patients were evacuated from a cruise ship off Cape Verde on Wednesday amid a hantavirus outbreak, as a new case was confirmed in Switzerland.