SAN JUAN, Puerto Rico -- Authorities on the eastern Caribbean island of St. Lucia said Thursday that they quarantined a cruise ship with some 300 people aboard after discovering a confirmed case of measles aboard.
Dr. Merlene Fredericks-James, the island's chief medical officer, told The Associated Press the ship was still in port and no one had been allowed to disembark since its arrival.
"One infected person can easily infect others," she said in a public statement.
Fredericks-James said a doctor aboard the ship requested 100 doses of the measles vaccine, which St. Lucia is supplying for free. She also said surveillance is necessary because the incubation period ranges from 10 to 12 days before symptoms occur.
An official with St. Lucia's Marine Police identified the ship as the Freewinds. The official declined to provide their name because they were not authorized to speak to the media.
The 440-foot ship reportedly belongs to the Church of Scientology. An unidentified person who answered the phone at the church's media center said no one was immediately available for comment.
The ship is normally docked in the Dutch Caribbean island of Curacao and serves as a religious retreat, the church's website says.
According to an online tracking website, the Freewinds arrived in St. Lucia on Tuesday and was supposed to be at Dominica on Friday. It was unclear where the ship might go next as a result of the quarantine.
Fredericks-James said St. Lucia authorities were not holding the vessel. "The ship is free to leave our port anytime it wishes," she said.
St. Lucia authorities did not immediately provide an update on the female crew member who contracted measles. Symptoms include runny nose, fever and a red-spotted rash. Most people recover, but measles can lead to pneumonia, brain swelling and even death in some cases.
Measles has sickened more than 700 people in 22 U.S. states this year, with federal officials saying the resurgence is driven by misinformation about vaccines.