June 25, 2020

PMA offers updates on Cyclospora outbreak linked to bagged salads

The Centers for Disease Control has updated that in cooperation with Fresh Express Inc., and out of an abundance of caution, ALDI has removed Little Salad Bar Garden Salad from select stores as a precautionary measure due to possible Cyclospora infection.

Max Teplitski, PMA Chief Science Officer

The recall affects all product codes of ALDI Little Salad Bar Garden Salads with use-by dates of May 16 to July 04 and distributed in the states of Arkansas, Illinois, Iowa, Indiana, Michigan, Minnesota, Missouri, North Dakota, South Dakota and Wisconsin between May 1 and June 19.

We are anticipating additional details from the CDC and FDA on their investigation of an outbreak of Cyclospora linked to private-label garden salad blends sold in the Midwest. As the implications extend beyond the immediate outbreak response, we wanted to share a brief perspective of the strong seasonality profile for these outbreaks. We also want to share the technical advances, already in play, which are changing the public health response time and will improve the industry’s ability to develop mitigations and interventions. The key factors, at this time, that most inform collective and coordinated industry actions include:

  • Since 2000, there have been more than 42 outbreaks in the U.S. attributed to the human parasitic pathogen Cyclospora cayetanensis (CDC Fact SheetFDA Fact Sheet, and Blue Ribbon Report).
  • Of the approximately 42 outbreaks, as a generality, almost 80% hit like clockwork from late April or early May through July.
  • Approximately 40% of the outbreaks have a known or suspected association with produce consumption both imported and domestically produced.
  • Many outbreaks are not resolved as to source of exposure or involvement of food.
  • Several seasonal outbreaks, including during this May onset window over the past three years, also tend to have a geographic regional aspect of exposure/ point of sale or consumption.
  • Recently validated molecular techniques, which, for the first time, discriminate C. cayetanensis (Cc) subtypes, are dramatically altering and improving the ability to include or exclude individual cases or clusters of cases.
  • These techniques, based on mitochondrial genome sequence variation*, are beginning to help resolve or provide clues to source-tracking during large and overlapping multistate outbreaks. Based on epidemiology and trace back information, these contemporary or overlapping multistate illnesses are likely to be from different food or environmental vehicles, distribution sources and geographic sources of endemic origin.
  • Recent studies using this mitochondrial genome sequence technique demonstrated important clarity and discriminatory power among clinical Cc isolates from different states, suggesting different original sources and potentially providing future predictive insights.
  • New research findings make it clear that Cc may be found in domestic water sources and the environment beyond U.S. southern border states.
  • Ongoing and newly funded research by the Center for Produce Safety are defining the prevalence and distribution of Cc using these modern detection tools developed by FDA scientists. CPS funded research is also evaluating the effectiveness and practical cost-effectiveness of potential interventions.
  • The speed of recognizing an emerging Cyclospora outbreak has taken a major step forward with several studies validating a platform called BioFire FilmArray GI now being used widely in public health labs. Cc, whether or not suspected and ordered by a physician for testing in a diagnostic panel from a patient, may now be detected in hours rather than days.
  • This rapid detection in clinical samples is likely to improve the opportunity to detect Cc in product samples and, potentially, improve the chances of determining the specific food vehicle in multicomponent products.

What does this mean for the industry at large?

At this time, outside of the outbreak investigation, trace back efforts, and consumer awareness and outreach underway, there are no new specific actions possible for growers, shippers, handlers or the industry at large. However, being informed is always an advantage. It is important to appreciate that these new tools are, for the first time, putting more standardized and reproducible research and public health protection platforms in the hands of a broader group of scientists and epidemiologists. The anticipated benefit is a much-improved opportunity for guiding both the epidemiology and trace back efforts in real time. The results will help to resolve specific food vehicles or environmental sources and targeted root cause analysis for future supply chain preventive controls.
Read more here for additional information and a quick digest of on the most recent developments and studies that have come out since the 2019 Blue Ribbon Panel report.   This digest provides more information on seasonality, detection and challenges associated with epidemiological studies.

PMA SciTech team will keep you updated as we learn more about the outbreak, and as new relevant data emerges.

— Max Teplitski, chief science officer, Produce Marketing Association