There are very rare but occasional outbreaks in places where mice and rats breed uncontrolled. Public parks mostly in Arizona, California, Colorado and New Mexico where the rental cabins are not occupied for part of the season. The rodents take over the cabins and then humans show up and get infected. Hantavirus is very rare. There have been less than a few hundred cases in the last few decades. There is a rare strain of Hanta in South America has has a 40-50% fatality rate but in most strains the fatality rate is 20% to 40%. It is also very rare in South America and Africa.
If that ship has been overtaken by rodents infected with Hanta then quarantine the ship, eliminate the rodents and sanitize the ship. Or capture all the mice and release them into the underground missile cities.