American Senator Richard Blumenthal called on cruise lines to halt all cruise operations and urged health agencies to impose stricter curbs. Cruise ships are “repeating recent history as petri dishes of Covid-19 infection,” Blumenthal, said.

“Time for CDC and cruise lines to protect consumers and again pause, by docking their ships,” he tweeted.

Despite vaccination requirements and stricter mask rules, the number of positive cases aboard ships surged in the past week.

Ships have been turned away from several ports.

Puerta Vallarta denied Holland America’s Line Koningsdom entry on Thursday after 21 crew members tests positive for COVID-19.

The Carnival Freedom was turned away from Bonaire and Aruba on Wednesday and Thursday after passengers tested positive.

Royal Caribbean’s Odyssey of the Seas was denied docking in Aruba and Curacao on Wednesday after 55 vaccinated crew members and passengers aboard the

The Seven Seas Mariner was turned away from Cartegena, Colombia Wednesday after six crew members and one passenger tested positive.

The Queen Mary, Queen Victoria and Wind Surf cruise ships were denied docking at the British Virgin Islands on Sunday due to a rising number of cases onboard.

The Centers for Disease Control and Prevention (CDC) is investigating 86 cruise ships. Of those, Carnival operates 32, Royal Caribbean Cruises Ltd. operates 25 and Norwegian Cruise Line Holdings Ltd. operates 15. Four ships operated by Walt Disney Co.’s Disney Cruise Line are now also under watch, according to the CDC website.

Bloomberg News reported that Bari Golin-Blaugrund, a spokesperson for the Cruise Lines International Association (CLIA) emailed, “Health and safety is the cruise industry’s highest priority. In fact, the latest data show that cases have occurred less frequently on cruise ships than on land, with a greater proportion of asymptomatic or mild cases.”