Officials of the Caribbean nation St. Lucia have quarantined a cruise ship reportedly owned by the Church of Scientology after doctors confirmed a case of measles onboard.

A female crew member has a confirmed case of measles, and the ship has been quarantined since Monday, according to NBC News. There are reportedly more than 300 passengers on board.

Though health officials in St. Lucia did not identify the ship or its owner, St. Lucia Coast Guard Sgt. Victor Theodore told NBC News that the vessel’s name is Freewinds, which is the name of a cruise ship owned by the Church of Scientology and based in the Caribbean. According to the Church’s website , the 440-foot vessel hosts religious retreats “ministering the most advanced level of spiritual counseling in the Scientology religion.”

In a statement Tuesday, St. Lucia's chief medical officer Dr. Merlene Fredericks-James said that “because of the risk of potential infection, not just from the confirmed measles case but from other persons who may be on the boat at the time, we thought it prudent to make a decision not to allow anyone to disembark.”

St. Lucia declared measles eliminated in 2016, as did the whole of the Americas. That means that it has been free of local measles transmission, which was last reported in St. Lucia in 1991. Still, health officials there are rightly cautious about international travelers importing the highly contagious virus. “[W]e cannot become complacent, as measles still circulates in other parts of the world,” Dr. C. James Hospedales, executive director of the Caribbean Public Health Agency, said at the time. “Due to the high intensity of international travel related to the large tourism sector, the Caribbean region remains at high risk for the importation of measles and rubella cases.”

Measles is currently making a raging comeback elsewhere in the world. The World Health Organization reported last month that global cases of measles increased 300 percent in the first three months of 2019 as compared with the first three months of 2018. The US is grappling with the deadly disease, with nine current outbreaks and over 700 confirmed cases already this year—that’s the highest number of cases since 1994.

Health officials in the US and elsewhere largely blame the resurgence of measles on vaccine hesitancy and misinformation about vaccine safety and efficacy. A small but vocal number of anti-vaccine advocates have worked tirelessly to cast doubt on the firmly established safety of life-saving immunizations. They also often downplay the risks of the severe and life-threatening diseases that the shots prevent.

As noted by The New York Times, the Church of Scientology has not taken an official stance on vaccination. Asked directly about its position on vaccination in 2016, the Church released a statement to The Hollywood Reporter saying that it “takes no position one way or the other on this issue.” But several high-profile celebrities connected to the church have spoken out against vaccination. The Church has also hosted notable anti-vaccine advocates such as Robert F. Kennedy Jr. in the past.

The Church’s ship, Freewinds, is slated to leave St. Lucia at 11:59pm Thursday, according to NBC News.