CDC activates emergency center as hantavirus outbreak spreads on cruise ship

The CDC has activated its Emergency Operations Center and placed the hantavirus outbreak aboard the MV Hondius at Level 3, the agency’s lowest emergency activation, as health officials tracked a cluster that has already included three deaths and kept changing from one update to the next. In practice, Level 3 means the CDC is monitoring the situation and can support the response without signaling the highest domestic risk.

The outbreak has centered on the Oceanwide Expeditions cruise ship as it traveled from Ushuaia, Argentina, toward Cape Verde and then the Canary Islands. The World Health Organization said that as of May 4, 2026, seven cases had been identified aboard the vessel, including two laboratory-confirmed infections and five suspected cases. That group included three deaths, one critically ill patient and three people with mild symptoms. WHO said illness onset occurred between April 6 and April 28, 2026, and that further laboratory testing was still ongoing as investigators treated the episode as a cruise-ship cluster.

Case counts have continued to shift. ABC News later reported five confirmed cases tied to the ship outbreak, while live updates said the suspected total stood at 12. More than 100 passengers remained on board during the response, and WHO said it was monitoring their health. The ship carried 147 passengers and crew, according to the agency.

U.S. officials said the risk to the American public was extremely low. The Department of State was leading a coordinated, whole-of-government response that included direct contact with passengers, diplomatic coordination and engagement with domestic and international health authorities. In the United States, Arizona health officials were monitoring one resident who had been a passenger, while Georgia officials were following two residents who had returned home. None had shown signs of illness.

The response has also spread beyond the United States. The UK Health Security Agency said British passengers and crew would be asked to isolate for 45 days after returning to the UK, reflecting the long incubation period being used in follow-up monitoring. Spanish authorities prepared a transfer plan for the vessel off Granadilla de Abona, Tenerife, with passengers expected to move ashore in controlled stages for medical screening and onward travel rather than dock normally.

The outbreak has drawn attention because hantavirus is usually rodent-borne and is not typically associated with cruise ships. Officials have not said how the virus moved through the vessel, and the strain under investigation has raised concern because some experts say it may be capable of person-to-person spread. For now, authorities continue to describe the overall public-health risk as low while they work to determine how far the cluster extends.