Cleaner public restrooms on cruise ships may decrease the incidence of norovirus, according to a study published in medical journal Clinical Infectious Diseases.

A team of Boston-based universities and health organizations found "widespread poor compliance" with cleaning protocols on 56 ships the team visited over a three-year period.

According to the report, only 37% of toilet area objects were cleaned on a daily basis in 273 randomly selected public restrooms.

The researchers said that since norovirus outbreaks frequently occur among closed populations and because environmental contamination is believed to play an important role in its propagation, they concluded that enhanced public restroom cleaning may prevent or moderate norovirus outbreaks on cruise ships.

The team said that in doing its research, it "covertly evaluated the thoroughness of disinfection cleaning" of six bathroom objects – the toilet seat, flush handle or button, toilet stall inner handhold, stall inner door handle, restroom inner door handle and baby changing table.

It did not specify which cruise ships it had visited.

The study said that its findings did not correlate with the Centers for Disease Control and Prevention's Vessel Sanitation Program inspection scores. More than half of the vessels that received poor scores in the recent study were given near-perfect CDC sanitation scores, according to the study.

CLIA issued a statement in response to the study.

"The limitations of this research raise appropriate questions that must be answered before a more complete assessment is reached," CLIA said. "It is worth highlighting that the [study] was not designed to investigate the causal relationship – and did not find one – between the thoroughness of disinfecting public restrooms and outbreaks aboard cruise ships.”

CLIA also said that its public health and sanitation procedures “go above and beyond this study’s focus on the disinfecting of public restrooms” and are “highly effective in maintaining healthy settings for families on vacation.

According to the CDC, the vast majority of norovirus outbreaks take place at land-based locations such as schools, daycare centers, hospitals and nursing homes.