Virus outbreaks on cruise ships mirror trend on shore

Suffering a bout of gastrointestinal illness in a cramped cruise ship cabin ranks pretty high on the scale of vacation nightmares. And given the bug going around this year, illness at sea is likely to spike.

Last week, Celebrity Cruises’ Mercury ship returned to port in Charleston, South Carolina, from a sailing during which more than 20 percent of passengers — about 400 — fell ill.

The Vessel Sanitation Program, an arm of the Centers for Disease Control and Prevention, inspected the ship in Charleston and identified the culprit as norovirus, which causes vomiting and diarrhea. VSP can’t say for sure where the virus originated.

“There were cases on the first day that were passenger cases, and there certainly is a connection with respect to increased norovirus in South Carolina. So it could have been from a passenger,” said Capt. Jaret Ames, branch chief of the VSP, which works with the cruise industry to prevent and control gastrointestinal illnesses.

High rates of norovirus illness on shore typically translate to cruise ships, Ames said. Outbreaks also frequently occur in other confined areas, including schools and nursing homes.

South Carolina’s Department of Health and Environmental Control has reported more than twice the usual number of norovirus outbreaks or unknown outbreaks that appear to be norovirus since early January.

By February 24, the agency had identified about 40 outbreaks compared with about 15 by that time in the past few years, according to spokesman Adam Myrick.

Fourteen of those outbreaks occurred in a school or university setting and more than 20 in long-term care facilities, compared with 3 to 5 in each of those types of facilities in the same timeframe in recent years. The agency does not track outbreaks on cruise ships that originate from the state.

South Carolina isn’t alone in seeing a jump in norovirus illness.

“You can see [norovirus increases] right now shore side, from the East to the West Coast, from other countries — and we have a new strain,” said Ames.

The VSP’s investigation did reveal some sanitation issues on the Mercury.

“We did find some problems with things like dishwashing. The machines were not operating, at least when we were on board, as they’re designed,” Ames said. Final sanitizing temperatures were inadequate, he said.

The investigation also uncovered a few things that needed to be corrected in the laundry operation and cabin disinfection, Ames said.

Celebrity delayed Mercury’s next sailing to thoroughly clean the ship and address issues revealed in the investigation, said Celebrity Cruises spokeswoman Cynthia Martinez.