Both ships increased disinfection and cleaning measures and isolated sick guests and crew, among other steps. Princess and Viking did not immediately respond to USA TODAY’s requests for comment.

Viking Cruises' unique ship designs, being small and almost identical, set the company apart and serve as an important value ...

Photograph by ROBERT CLARK-PHOTOGRAPHED AT VIKING SHIP MUSEUM, MUSEUM OF CULTURAL HISTORY ... Photograph by David Guttenfelder In 2008 a work crew laying an electrical cable discovered human ...

At 443 feet in length, each accommodates 190 passengers and 53 crew members. On Portugal's Douro River, Viking operates four ...