Every other month, the US Food and Drug Administration (FDA) hosts a webinar to highlight ongoing research and innovation underway across all of the agency’s branches and the role it plays in advancing public health. This month, the conversation focused on food safety, and more specifically, how the FDA identifies, tackles and studies foodborne illness outbreaks, with an emphasis on a common culprit: romaine lettuce.
The lecture, entitled “FDA Grand Rounds: The CORE Network (or How I Learned to Love Lettuce…),” was hosted by the FDA’s Coordinated Outbreak Response and Evaluation (CORE) Network Director, Stic Harris. CORE Network was created not only to manage foodborne illness outbreaks, but also to surveil and study post-response activities relating to illnesses linked to FDA-regulated food, supplements and cosmetics.
Since it was founded in 2011, CORE has been working alongside the Centers for Disease Control and Prevention (CDC), FDA field offices and state agencies to fight foodborne illness outbreaks. During the presentation, Harris emphasized the role that collaboration between the agency and its partners plays in not only identifying outbreaks, but further analyzing them to understand emerging outbreaks.
Harris explained CORE’s process of identifying an outbreak, starting with its Signals and Surveillance Team. In collaboration with the CDC and other agencies, the team reviews past inspections and sampling results, among other data. When an outbreak is linked to an FDA-regulated food, the information is passed to a designated Response Team to control and stop the outbreak.
Since 2011, CORE has been a major player in identifying nearly 1,000 potential outbreaks, including 234 food-related outbreaks, as well as warning consumers to avoid those foods through 400 public advisories. Each week, CORE updates an online database of ongoing outbreak investigations that can be viewed here.
After the presentation, Harris took audience questions where he addressed romaine lettuce and why it is so susceptible to E. coli contamination. When asked whether there was something specific about the leafy green that made it a common culprit, Harris described it as “poop in a cup.” Since lettuce requires plenty of irrigation water during cultivation, cross-contamination often causes an E. coli outbreak. For example, in three years, there have been nine E. coli outbreaks linked to the same romaine lettuce grower.
Harris noted that supply is a particular challenge associated with an outbreak of perishable items like lettuce — by the time an illness is confirmed, there is often not enough product left to test. Another issue that Harris brought up is that nearly half of the records that are examined by CORE teams are on paper, sometimes resulting in poor recordkeeping.
However, a positive takeaway from the presentation was the potential of whole genome sequencing (WGS) in helping detect outbreaks. Harris said that WSG can more accurately identify pathogens compared to its predecessor (pulsed-field gel electrophoresis), and thus identify more outbreaks at a higher rate. WSG can also be used to identify past outbreaks.
When questioned about COVID-19’s effect on food safety, Harris said that it is still too early to know the full impact since there weren’t any announced outbreaks during the first quarter of 2020. As the year went on, 25 total outbreaks were recorded, but Harris was hopeful that WSG and other emerging technologies can help identify and prevent more.