Dive Brief:

• Salmonella infections rates fell more than 5% in New York City from 2011 to 2015, starting one year after the health department adopted a letter-grade system, according to research from the University of Minnesota School of Public Health and that state's food safety center. The rate of salmonella cases in New York state —which doesn't have a standardized, statewide policy for reporting inspection results — didn't fall during the same time period.
• Eighty-eight percent of consumers surveyed in 2012 said they considered the letter grades when deciding where to eat. The researchers similarly concluded that the letter grades posted at point-of-service contributed to a decline in salmonella cases in NYC restaurants, where 35% more businesses earned an A rating than did under the points-only system.
• Though salmonella causes more hospitalizations and deaths than any other foodborne illness, case rates have not "substantially changed" in the past 20 years, the report said. U.S. consumers spend half of their food expenditures at restaurants, up from 33% in 1970, and restaurants were linked to 60% of foodborne illness outbreaks in 2015.

Dive Insight:

Foodborne illness outbreaks harm bottom lines as well as reputations and customer loyalty. Researchers at Johns Hopkins' Global Obesity Prevention Center estimated that one outbreak could cost a fast food restaurant a few thousand dollars to $1.9 million and a fast-casual restaurant up to $2.1 million. Per their simulation, a 50-person salmonella outbreak at a fast food restaurant would cost $1.7 million.

Perhaps the most poignant data about salmonella in New York's experience originated in the city's own reporting two years into the new system. In 2011, the first full year with letter grades, reported salmonella cases dropped 14% from 2010, or 175 cases — the lowest level in 20 years. Neither New York state nor neighboring Connecticut or New Jersey posted similar declines. That might not sound like much, but the CDC says for every case reported, 28 are not. So in New York City, that 14% decline equals 5,075 fewer cases of salmonella infection.

The city adjusted its points system, developed in 2005, to include A-B-C (or "grade pending") in 2010 to nurture transparency, improve sanitary conditions and diminish risks of foodborne illness in restaurants. Restaurants that don't earn an A on the inspector's visit have a month or so to prepare for a follow-up visit, at which point they will receive their formal grade.

In that 2012 survey by Baruch College, almost 40% of New Yorkers reported they were "very concerned" about possibly getting sick at the city's restaurants, delis and bodegas. Where fines seem to have failed, the public letter system has shined. In 2012, 41% of first inspections earned an A, compared to 27% in the first six months of 2010 and 35% by the end of that year. Two years into the new system, 72% of restaurants posted A's by the second inspection.

As the second most common foodborne illness, salmonella can easily spread in restaurants as it doesn't favor any particular types of food. The CDC says it can contaminate meat and eggs, fruits and vegetables, spices and nuts. Worker health, hygiene and better food handling practices can isolate most salmonella cases. Outbreak cases (defined as two or more cases from the same source) comprise less than 10% of salmonella infections, according to the Minnesota researchers' report.

While not everyone agrees on the merits of publicly posting inspection grades, these findings make it harder to dispute the efficacy. If a Scarlet Letter-type system can incite restaurants in the nation's most populous city to change, smaller jurisdictions with fewer resources might consider the power of public shaming. (Some think the system could benefit wholesalers and delivery companies, too.) Technically consumers have access to city data, and crowdsourced sites from Yelp to "I Was Poisoned" offer unvetted information, but generally people trust restaurants to prepare food safely. Once that trust is broken, it can be hard to bounce back. Chipotle learned this the hard way after major public stumbles and is only now turning things around. Larger chains may have more financial support to stay afloat, but often independent restaurants aren’t so lucky.