CDC-FoodNet2014As in previous years, the latest federal data on trends in foodborne illness rates are a mixed bag. “The overall outlook is that there is some good news and I think we can learn from that, but that the news is not all good and there’s still a lot of work to do,” said Patricia Griffin, chief of the Enteric Diseases Epidemiology Branch at the U.S. Centers for Disease Control and Prevention’s Division of Foodborne, Waterborne and Environmental Diseases. According to the Foodborne Diseases Active Surveillance Network (FoodNet), there were a total of 19,542 infections, 4,445 hospitalizations and 71 deaths reported in 2014. Some types of infections declined, some increased, and some stayed the same. FoodNet is a collaboration between CDC, 10 state health departments, the U.S. Department of Agriculture’s Food Safety and Inspection Service (FSIS) and the Food and Drug Administration that tracks incidents of Campylobacter, Listeria, Salmonella, Shigella, Shiga toxin-producing E. coli (STEC) O157, STEC non-O157, Vibrio, Yersinia, Cryptosporidium and Cyclospora. The number of laboratory-confirmed illnesses falls far below the actual number of people sickened by foodborne pathogens each year. CDC estimates that 48 million illnesses, 128,000 hospitalizations and 3,000 deaths are linked to foodborne illness annually. CDC uses FoodNet data to help develop these estimates. Along with the regulatory agencies, the agency also uses it to track progress in reducing infections.

The figure above is a line chart showing relative rates of culture-confirmed infections with Campylobacter, Shiga toxin-producing Escherichia coli O157, Listeria, Salmonella, and Vibrio compared with 2006-2008 rates, by year, in the United States during 2006-2014. Source: CDC
  Looking at the 2014 data, Salmonella was the most frequent cause of infection, accounting for 38 percent of them. Campylobacter was second with 33 percent, and E. coli caused 6 percent. The good news is that the frequency of E. coli O157 infections have decreased, compared with both the baseline years of 2006-2008 and the previous three years. “That’s great news and suggests that our control measures are working,” Griffin told Food Safety News. CDC had been concerned when last year’s data showed an increase in E. coli infections, suggesting that progress may have stalled. When it comes to Salmonella, CDC wants to emphasize that serotypes are diverse. “The unchanged overall incidence of salmonellosis masks substantial changes in infection with individual serotypes,” reads the report. CDC highlighted that the number of infections from the second most common strain of Salmonella — Typhimurium — continues to decrease, while there have been statistically significant increases over the baseline in two other serotypes. Javiana, the fourth most common serotype, was 131 percent higher, and Salmonella Infantis, the sixth most common, increased 160 percent compared to the baseline and was also “significantly higher” than in 2011-2013. Salmonella Heidelberg — the strain more on the public mind thanks to Tuesday’s FRONTLINE episode — ranked as the seventh most common serotype, and Griffin said the agency has not seen a significant change in Heidelberg infections compared to either the baseline or the previous three years. Because of the differences among the serotypes, “looking at them separately, we think is the way to address prevention,” Griffin said during a media briefing.
The figure above is a line chart showing incidence per 100,000 population of culture-confirmed infection with Salmonella serotypes Typhimurium, Javiana, and Infantis, by year, in the United States during 2006-2014. Source: CDC
  CDC also notes an increasing incidence of non-O157 STEC infections is attributable, in part, to an increase in the number of laboratories testing for Shiga toxin. The top non-O157 serogroups isolated from patients were O26, O103 and O111. And compared with 2006-2008, FoodNet’s 2014 data showed a 52-percent increase for Vibrio and 13-percent increase for Campylobacter, trends also observed in 2013. Last year, it was noted that although Vibrio accounted for only 1.3 percent of the reported infections in 2013, its incidence increased 32 percent from 2010-2012. “Clearly more work is needed,” Griffin said. “Targeted prevention efforts and continued close monitoring of foodborne illness is key.”