The Centers for Disease Control and Prevention Morbidity and Mortality Weekly Report has released information about incidence and trends of foodborne illness from their active surveillance network for 2016 – 2019. They have found that foodborne illnesses increased, so the Healthy People 2020 targets for reducing foodborne illness will not be met.
In 2019, FoodNet identified 25,866 cases of infection, 6,164 hospitalizations, and 122 deaths. The overall incidence per 100,000 population was highest for Campylobacter, followed by Salmonella, STEC, Shigella, cyclospora, Yersinia, Vibrio, and Listeria. Eighty-six percent of infections were acquired domestically. It’s important to note that most cases of foodborne illness are not reported to physicians, so those cases are not in the FoodNet system.
In 2019, compared with the previous three years, the incidence of infections caused by pathogens that are commonly transmitted through food increased for Campylobacter, cyclospora, Shiga toxin-producing E. coli, Vibrio, and Yersinia, and remained unchanged for Listeria, Salmonella, and Shigella. The report states, “The identification of infections that might not have been detected before adoption of culture-independent diagnostic tests (CIDTs) cannot explain this overall lack of progress.”
For Salmonella, eggs and chicken are the major sources of this pathogen. And many infections are now caused by a new, highly resistant strain of Salmonella found in chicken.
Laboratory diagnosed non-O157 E. coli infections continue to increase, while E. coli O157 infections appear to be decreasing. Outbreaks to leafy greens continue. Produce is also an important source for cyclospora, Listeria, and Salmonella.
Many labs now use CIDTs for rapid diagnoses and they do find infections that would have been undiagnosed in the past. And in 2019 public health labs fully transitioned their standard sub typing method for clinical bacterial isolates from pulsed-field gel electrophoresis (PFGE) to whole genome sequencing (WGS). That test provides more detailed information to more effectively recognize outbreaks, determine patterns to antibiotic resistance, and investigate bacterials trains that are emerging, reoccurring, and persisting.
The report states that since foodborne illnesses increased, new strategies that target particular serotypes, along with more widespread implementation of known prevention measures, are needed. For instance, for Salmonella, more chickens should be vaccinated against the different serotypes of the pathogen. In addition, continued implementation of the FDA’s Produce Safety Rule should be increased, including expanded surveillance inspections of foreign. and domestically grown produce.
