06/12/09: Study links dirty bathrooms to cruise illnesses

As an agent with Apollo Travel in Melbourne, Gaetana Ferraro said she sails on cruise ships about twice a year, with the most recent trip last July aboard Royal Caribbean’s Mariner of the Seas out of Los Angeles.

So she was shocked to hear that a recent study of cruise ship public bathrooms revealed that out of 273 restrooms checked on 1,546 occasions, only 37 percent of them were cleaned daily.

“My God. . .usually, they’re pretty clean,” said Ferraro, who’s already booked on a New Year’s cruise.

Some of the seven local ships from Port Canaveral, carrying 20,000 passengers a week, were in the study. However, it was not broken down ship-by-ship due to confidentiality and because results have not yet been released to the cruise lines. Still, Carnival, Royal Caribbean and Disney ships have received mostly favorable marks when rated on sanitary conditions by the Centers for Disease Control. All three cruise lines declined to comment on the latest study.

A team of researchers from Boston University School of Medicine, Carney Hospital, Cambridge Health Alliance and Tufts University School of Medicine, conducted the study, published in the most recent issue of Clinical Infectious Diseases.

The main finding: Widespread poor compliance with regular cleaning of public restrooms on cruise ships may predict subsequent norovirus-caused gastrointestinal illness outbreaks.

During the testing period, the Centers for Disease Control and prevention investigated a total of 66 gastrointestinal outbreaks on 47 ships, affecting nearly 10,000 passengers and crew members. The norovirus was the agent in 97 percent of those cases.

In 2006, hundreds of cruise ship passengers came down with norovirus twice aboard Royal Caribbean’s Mariner of the Seas.

Following those incidents, the Centers for Disease Control and Prevention sent a team of environmental health officers and epidemiologists from their Vessel Sanitation Program to the ship after it returned to Port Canaveral “to review medical logs and procedures, and to monitor the cleaning and disinfection procedures.”

The latest study involved a small army of secret testers — 38 nurses, four doctors and four health professionals — who evaluated restrooms on 56 large cruise ships from July 2005 through August 2008.

The health professionals tested six surfaces in bathrooms: toilet seats, flush handles or buttons, toilet stall inner handhold, stall inner door handle, restroom inner door handle and baby changing table surfaces. They squirted a transparent, soap-based, easily cleanable solution on the surfaces and then checked them with a blacklight the next day to see if the surfaces had been washed. A little less than two-thirds of the time, most objects had not been touched by cleaning crews.

However, toilet seats were more apt to be cleaned than anything else, with workers disinfecting that surface at least half of the time.

Rails in bathroom stalls were the least-likely object to be cleaned, with half of those not touched at all.

Perhaps most worrisome, on three ships, none of the baby changing tables was cleaned during the study period.

The three cruise lines that sail out of Port Canaveral referred requests for comment to the Cruise Lines International Association.

“The cruising industry takes the sanitation of its vessels and the mitigation of all gastrointestinal illnesses, including norovirus, very seriously,” said Lanie Fagan, a CLIO spokesperson.

All of Port Canaveral’s ships are monitored by the Centers for Disease Control and Prevention’s Vessel Sanitation Program, which is not affiliated with this study.

Cruise Line International Association officials say they have limited knowledge of the study’s methodology and are unable to reconcile its conclusions with the industry’s public health and sanitation procedures.

“We have reached out to the authors to learn more about how the study was done and certainly we anticipate sharing some of the industry’s practices and procedures,” Fagan said. “Based on these discussions we should be able to determine whether any additional actions are appropriate.”