Today the Centers for Disease Control and Prevention (CDC) released two new articles that provide an updated analysis of the incidents of foodborne illness in the United States. The study, broken into two articles—one covering 31 major pathogens and the other covering unspecified foodborne agents—concludes that each year in the United States 47.8 million foodborne illnesses, 127,839 hospitalizations, and 3,037 deaths occur due to consumption of contaminated food. 

Of the 31 major pathogens accounted for in the study, norovirus caused the most illnesses; nontyphoidal Salmonella spp., norovirus, Campylobacter spp., and T. gondii caused the most hospitalizations; and nontyphoidal Salmonella spp., T. gondii, Listeria monocytogenes, and norovirus caused the most deaths. (Tables 1–3 below list the top 5 pathogens causing illness, hospitalization, and death.)

The 47.8 million number, while huge, is a marked reduction from the annual estimate announced in the last comprehensive study seeking to calculate the number of illnesses caused annually by foodborne pathogens. The previous study, by Mead et al released in 1999, estimated that foodborne pathogens caused 76 million episodes of illness, 325,000 hospitalizations, and 5,000 deaths each year. Those numbers have been often repeated to hammer home the magnitude of the food contamination problem in this country.

So based on the new study, the question becomes—is the US food supply safer today than it was 11 years ago? As well explained by Dr. J. Glenn Morris, Jr., director of the Emerging Pathogens Institute and associate editor of the CDC’s Emerging Infectious Diseases journal, the majority of the reduction in reported foodborne illness comes from substantial changes in how the authors of the new study used advanced treatment of statistical uncertainty and variability and their transparent inclusion of voluminous appendixes of data, models, and assumptions.

In fact, if you looked at the overall rates of acute gastrointestinal illness between 2000 and 2007, it appears that rates per person have actually increased (from 0.49 episodes per person per year in 2000–2001, to 0.54 in 2002–2003, and to 0.73 in 2006–2007). Also helpful is looking at data from FoodNet, a laboratory-based sentinel surveillance system that was established to monitor the public health impact of the 1995 US Department of Agriculture (USDA) Pathogen Reduction: Hazard Analysis and Critical Control Point (HAACP) System regulations.  Review of actual reported cases for 10 foodborne bacterial and parasitic pathogens shows an initial drop in incidence of infection with these 10 major bacterial foodborne pathogens after implementation of the 1995 USDA regulations, followed by a leveling off of incidence in subsequent years. Dr. Morris keenly points out that with the exception of cases of Vibrio, which has clearly increased over the years, foodborne illness does not seem to be getting worse, nor is it getting any better.

The bottom line is that the CDC’s new study continues to highlight the same point as the Mead et al study from 1999—foodborne pathogens needlessly injure and kill thousands of people every year in the United States. We can, and need to, do better.

 

Table 1. Top five pathogens contributing to domestically acquired foodborne illnesses

 

 

Table 2. Top five pathogens contributing to domestically acquired foodborne illnesses resulting in hospitalization

 

 

Table 3. Top five pathogens contributing to domestically acquired foodborne illnesses resulting in death