Thirteen cases were identified among people on the ship, including three deaths, and officials used the six-week monitoring period because Andes virus symptoms have taken up to 42 days to appear.
Eighteen Americans were brought to Omaha after more than 120 people were evacuated in Spain’s Canary Islands; 10 were released earlier for home monitoring, and none of the final eight developed illness.
One passenger, Angela Perryman, said she was held under a disputed quarantine order after Florida refused federal demands for round-the-clock monitoring at home, calling the six-week stay a political stunt.
The outbreak on the Dutch cruise ship raised concern because Andes virus, unlike most hantaviruses spread through rodent contamination, may rarely pass between people.