Chapman says that while dirty bathrooms can be gross, like the gotcha moments on hidden camera programs, there really isn’t any information that suggests a place with a dirty bathroom is any more or less likely to cause an outbreak than a place with a clean bathroom. Lots of restaurants have separate handwashing facilities in the kitchen, and risk-based inspection systems focus on factors that lead to illness as identified by the CDC and WHO — not the floors, walls and ceilings, and how many flies are on a fly strip.

But what about on cruise ships?

A team of researchers from Boston University School (BUSM), Carney Hospital, Cambridge Health Alliance and Tufts University School of Medicine, have found that widespread poor compliance with regular cleaning of public restrooms on cruise ships may predict subsequent norovirus infection outbreaks (NoVOs).

Despite biannual sanitation monitoring and hand hygiene interventions among passengers and crew members, 66 ships monitored by the United States Centers for Disease Control and Prevention experienced NoV infection outbreaks (NoVOs) between 2003 and 2008.

Trained health care professionals evaluated the thoroughness of disinfection cleaning of six standardized objects (toilet seat, flush handle or button, toilet stall inner handhold, stall inner door handle, restroom inner door handle, and baby changing table surfaces) with high potential for fecal contamination in cruise ship public restrooms.

The researchers found only 37 percent of the 273 randomly selected public restrooms that were evaluated on 1,546 occasions were cleaned daily. The overall cleanliness of the six standardized surfaces on each ship ranged from four to 100 percent. Although some objects in most restrooms were cleaned at least daily, on 275 occasions no objects in a restroom were cleaned for at least 24 hours.