Norovirus confirmed aboard Mercury

Lab tests confirmed that the norovirus caused hundreds of passengers and crew to fall ill this week onboard the Celebrity Mercury, which returns to Charleston from an 11-day cruise this morning.

Halfway through the Caribbean, passengers began reporting stomach disorders symptomatic of the virus. By Tuesday, 419 of the 1,838 passengers and 27 of the 849 crew members had become sick.

Celebrity staff sent five stool samples to an independent facility and, according to the Centers for Disease Control and Prevention, all tested positive for norovirus. Three CDC officials will meet the Mercury at the Union Pier passenger terminal this morning.

Jay Dempsey, a CDC health communications specialist, said his agency would perform its own sampling, but officials did not expect results that differ from Celebrity's findings.

Norovirus symptoms include nausea, vomiting, diarrhea and stomach cramps, sometimes accompanied by a low-grade fever. The highly contagious illness usually lasts a day or two and spreads through food, water or person-to-person contact.

Katie Zimmerman, a project manager with the Coastal Conservation League, said she received frantic calls and e-mails from residents concerned not only about infected passengers entering the city but also about trash from the ship entering local waters.

Federal regulations for cruise ship waste require ships to travel at least 3 nautical miles offshore before dumping treated trash. They can dump untreated refuse at least 12 nautical miles offshore.

Celebrity does not discharge any waste within 12 nautical miles of land, according to Cynthia Martinez, a spokeswoman for Celebrity's parent company, Royal Caribbean Cruises. She said all wastewater passes through a treatment system before release, and that Celebrity would not treat the Mercury's circumstances any differently.

The 12-mile rule came as welcome news to Zimmerman, who added, "there's nothing legal to enforce that, since there are no (local) regulations here." The league supports a state or city ordinance that would establish set guidelines for cruise-ship disposal that extend beyond the federal regulations. "It should be in writing," Zimmerman said.

Wastewater from the Mercury poses no risk to marine life or people who eat local seafood, according to Mel Bell, director of fisheries management with the S.C. Department of Natural Resources.

"The only type of marine life we tend to be concerned about coming in contact with contaminated water is shellfish," Bell said. Shellfish filter-feed, but their beds grow along the shoreline, far from the waste disposal.

A human pathogen likely would not affect other marine life, he said, and saltwater is hostile to microorganisms that spread illness.

By Thursday a few dozen people remained quarantined on the Mercury, Martinez said.

She said Mercury employees launched "enhanced cleaning" to keep the sickness from spreading. That means intensively sanitizing high-traffic areas and the cabins of sick guests and crew, plus extra cleaning before the next wave of guests.

Another 1,880 passengers sail for Key West, Fla., onboard the Mercury this evening.

Reach Allyson Bird at 937-5594 or abird@postandcourier.com.