Gastroenteritis outbreaks on cruise ships: are sanitation inspection scores a true index of risk?

BACKGROUND: The utility of cruise ship sanitation scores as indicators of future gastroenteritis outbreak was investigated by means of a 5-year review of inspection scores and outbreaks of gastroenteritis as reported under the Vessel Sanitation Programme of the United States Public Health Centers for Disease Control.

MATERIALS AND METHODS: Between 2012 and 2017 a total of 1197 inspections were published online, with a mean score of 95.7 out of 100. During the same interval there were 50 separate outbreaks of acute gastroenteritis.

RESULTS: No significant difference was found between pre-outbreak inspection scores, mean 96.4, and inspections that were not followed by an outbreak, mean 95.1 (z = 0.81, p = 0.42).

CONCLUSIONS: This study shows that the current format of the inspection audits carried out under the Vessel Sanitation Programme generates scores that have no prognostic value with regard to future outbreaks of gastroenteritis on board cruise ships.