CDC Releases Foodborne Illness Report Card

Ricki Lewis, PhD

April 18, 2013

The Centers for Disease Control and Prevention (CDC) has released a report on the Foodborne Diseases Active Surveillance Network (FoodNet) results for 1996 through 2012. The findings, published in the April 19 issue of the Morbidity and Mortality Weekly Report, indicate that the overall incidence of selected monitored infections has not changed significantly in recent years, although Campylobacter and Vibrio infections have increased.

Each year, 1 in 6 people, or about 40 million individuals in total, become ill from contaminated food. FoodNet monitors the incidence and quantifies laboratory-confirmed cases of foodborne illnesses caused by 9 pathogens. The program tracks 10 sites through state health departments, representing 15% of the US population. It is a collaboration among the CDC, the US Food and Drug Administration, and the US Department of Agriculture.

"FoodNet is the nation's annual food safety report card. It provides information to help us know how we are doing in reducing foodborne illness. Tracking trends over time, such as which pathogens or infections are increasing and which are decreasing, offers insights into how to save lives and protect people," said Robert Tauxe, MD, MPH, deputy director, CDC Division of Foodborne, Waterborne and Environmental Diseases, at a news conference.

The report covers 19,531 infections that required 4563 hospitalizations, with 68 deaths. Included infections must have been diagnosed in a microbiological laboratory that isolates the pathogen.

Salmonella is the most commonly diagnosed and reported infection, and the frequency has remained constant since 1996. Cases of Salmonella serotype Typhimurium have decreased, although other serotypes have filled in the niche.

Campylobacter infections have increased by 14% since 2006 to 2008. Most infections come from undercooked or raw chicken or turkey, but they can also originate from unpasteurized raw milk and raw produce. However, incidence of Campylobacter still remains lower than in the 1990s, the report found. Campylobacter is difficult to evaluate because is typically sporadic, lacking the clues of an outbreak. The researchers cannot yet account for the increase seen between 2006-2008 and 2012.

Vibrio infections also increased since 2006 to 2008 but remain rare. Most of these infections come from eating oysters from marine waters, although wound infections also come from contact with Vibrio in marine waters.

Incidence of STEC O157 (Escherichia coli that produces Shiga toxin) infections were slightly higher than from 2006 to 2008, but the numbers have sharply declined since improvements in handling ground beef in the food industry began in the 1990s.

A general measure that combines data on 6 key pathogens found "general progress," with incidence of these foodborne illnesses down 22% from the late 1990s, but unchanged from that seen in 2006-2008.

Limitations of FoodNet include that it does not cover the entire country, that it includes cases that were not associated with food, and that it relies on laboratory detection of selected pathogens. The analysis does not include, for example, common foodborne illnesses such as those caused by norovirus, which clinical labs do not detect.

The authors have disclosed no relevant financial relationships.

Morb Mortal Wkly Rep. 2013;62:283-287. Full text