The Beneficial Impact of Restaurant Letter Grade Posting on the Occurrence of Salmonella

Introduction: Rates of Salmonella infection in the United States have not changed over the past 20 years. Restaurants are frequent settings for Salmonella outbreaks and are risk factors for sporadic Salmonella infections. A marked decline in foodborne illness hospitalizations was reported in Los Angeles County following the introduction of restaurant grade postings at the point of service.

Purpose: We sought to evaluate the potential for posting restaurant inspection letter grades at the point of service to reduce the occurrence of Salmonella.

Methods: We identified state and local jurisdictions that implemented grading of restaurant inspections wih posting of letter grades at the point of service. We, also, identified jurisdictions that posted inspection results other than letter grades at the point of service. For each jurisdiction, we obtained counts of Salmonella infections reported in the jurisdiction for the two years before the posting practice was implemented, for the year of the change, and for the two years after the change. Observed rates were compared to aggregate FoodNET Salmonella data.

Results: Six jurisdictions were identified that implemented letter grade posting of restaurant inspection results and had available Salmonella data. Six jurisdictions were identified that posted other inspection results. The mean rate of Salmonella in the letter grade jurisdictions declined from 15.0 cases per 100,000 population (two years before the change) to 11.2 cases per 100,000 population (two years after the change). These rates were significantly lower than comparable FoodNET rates for the year of change and the two following years (P<0.05). In jurisdictions that posted other forms of results, the rates did not change.

Significance: Posting restaurant inspection results at the point of service in the form of a letter grade reduced reported Salmonella cases in the jursdiction and, therefore, warrants broader use.