FDA’s Continued Microbial Sampling Yields New Data
In its ongoing quest to learn more about common environmental pathogens and identify patterns to reduce microbial contamination, FDA has been sampling selected foods. Earlier this year, we noted the agency’s zeroing in on herbs and focusing its radar on spices; now the agency has published reports on its avocado and its hot pepper sampling.
Hot Peppers. Of the 1,615 domestic and imported hot pepper samples FDA collected, tested and analyzed for Salmonella and E. coli STEC (including O157:H7), 46 (2.85%) were positive for Salmonella and 1 for a STEC strain that is not likely to cause severe illness.
Fresh Avocadoes. Of these 1,615 samples, 12 (0.74%) tested positive for Salmonella. Additionally, Listeria monocytogenes testing was conducted on 1,254 avocado pulp samples with 3 (0.002%) being positive, and 361 skin samples with 64 (17.73%) coming back positive.
FDA also provided a quarterly update (as of October 1, 2018) on its ongoing sampling, for which it has tested:
Fresh Herbs. Of 683 samples (407 domestic, 276 import), 9 (0.13%) tested positive for Salmonella (4 domestic, 5 import); 6 (0.009%) for non-illness producing STEC (2 domestic, 4 import), 4 (0.006%) for Cyclospora cayetanensis (2 domestic, 2 import), and none for E. coli 0157:H7.
Guacamole/Processed Avocado. Of the 474 samples (386 domestic, 88 import), 11 (0.02%) tested positive for Listeria monocytogenes (9 domestic, 2 import) and none for Salmonella.
While none of the numbers were high, it is interesting to note that the contamination rates for the avocado skin samples with Listeria monocytogenes were significantly higher than any of the others – nearly 18% with the next highest being just under 3%. This not only makes the note FDA included in the report quite applicable: “FoodSaftey.gov advises consumers to wash all produce before cutting into it or eating,” it proves, again, why the Jensen Farms case on the Listeria-contaminated cantaloupe outbreak provides such a cautionary tale for produce processors.
In addition to the sampling reports, the agency posted an FDA Voices blog, “Sampling Program Provides Scientific Foundation to Better Protect Consumers from Foodborne Pathogens” by CFSAN’s Director Susan Mayne and Director of the Office of Compliance William Correll. The blog discussed the purpose and objectives of the surveillance approach to sampling, which is different from “for-cause” sampling conducted in response to known contamination or an outbreak.
By analyzing 1,600+ selected samples, the agency is getting a sense of the levels of contamination on a targeted commodity, and can look for trends in produce subgroups in which there may be a higher prevalence of contamination. From that, if indices point to positive samples from a specific geographic region, FDA can initiate separate, targeted sampling activities to help clarify the extent to which contamination may be a concern for the sampled food or enable other investigation when applicable.
When sampling and analysis is completed, FDA determines if additional studies or mitigation efforts are needed.
When findings, combined with other data, indicate a relatively low risk, FDA may focus fewer future resources on that commodity.
When findings help the FDA better understand potential risks associated with a commodity, it may develop interventions to help address the risks, such as education and outreach, updated policies, more testing in specific areas, or targeted compliance activities.
If key knowledge gaps remain after analysis, FDA may encourage or initiate additional activities to fill the gaps, including additional sampling assignments or research studies.
As an example of this, when positive samples of domestic hot peppers and avocados were found, FDA worked with the responsible firms to conduct recalls as indicated, and followed up with inspections of growers and packinghouses to ascertain their adherence to recommended good agricultural and manufacturing practices. When FDA found positive results in imported product, it refused entry to all product in lots associated with the positive(s), and placed the firms on import alert to stop additional product from entering the U.S.
A key question is whether any of these results are surprising and if these data should change behaviors? As I already noted, it is certainly a strong recommendation to wash all produce before using it, but should you do more? The only surprise I had was he high level of Listeria monocytogenes on avocado skins. Which should emphasize the need for overall control of Listeria monocytogenes in the retail and restaurant environment when preparing, storing and serving ready-to-eat food such as avocado.
I am sure there are many that will come up with costly options to further reduce pathogens on the surface of avocados and other fresh produce items. Recognizing that one can never 100% mitigate the microbiological risk in a fresh produce item without some type of kill step, and in the interest of balancing economics and reducing exposure to any type of chemical, I don’t think the data support going beyond a good rinse under cold running water as the most economical and effective way to reduce risks.
About The Acheson Group (TAG)
Led by Former FDA Associate Commissioner for Foods Dr. David Acheson, TAG is a food safety consulting group that provides guidance and expertise worldwide for companies throughout the food supply chain. With in-depth industry knowledge combined with real-world experience, TAG's team of food safety experts help companies more effectively mitigate risk, improve operational efficiencies, and ensure regulatory and standards compliance. www.AchesonGroup.com