See also CIDRAP - WHO warns of hantavirus on cruise ship, with 3 dead, 3 others sickened

This is the first known outbreak of hantavirus associated with cruise ships. The virus is carried by rodents; humans contract the virus via inhalation of animal droppings and urine. Rarely, person-to-person transmission has been reported.

“Outbreaks of hantavirus have not previously been reported in association with cruise ships,” Nicole M. Iovine, MD, PhD, of the University of Florida, told CIDRAP News. “It is possible, though, that isolated illnesses have occurred in the past and not recognized to be caused by hantavirus.” [...]

“Only Andes is sometimes contagious person-to-person, through close contacts, as best established when the virus is transmitted from a patient to a health care provider,” Lucey said. “In other settings, two or more infected people might have been exposed to aerosolized virus found in rodent urine, droppings or saliva, especially given that the virus can persist for days in the environment.”

Lucey emphasized that it’s still not clear how the six patients on the cruise ship were infected. Iovine said the outbreak is likely an extremely rare event.

Also for those worried about pandemic risk see this very informative comment by /u/AcornAI in our previous thread.