The U.S. Food and Drug Administration (FDA) recently released the findings of a sampling assignment that collected and tested ready-to-eat (RTE) dips and spreads with the aim of determining the presence of Listeria monocytogenes and Salmonella. The findings will be reviewed to identify commonalities related to the contamination of RTE dips and spreads, which will inform FDA guidance and program priorities.
The sampling assignment was conducted in light of five recalls of hummus products and six recalls of multi-commodity dips caused by L. monocytogenes or Salmonella contamination that occurred in 2017–2020. The foodborne illness outbreaks that caused the recalls resulted in 43 confirmed cases, 27 hospitalizations, and three miscarriages.
Sampling for the assignment began in early March 2021 and sample collection and analysis was completed in January 2022. FDA collected and tested 747 samples for L. monocytogenes and Salmonella. Of these samples, the agency collected 743 domestic samples. The agency collected samples from as many different brands and manufacturers as possible, depending on inventory available at the time of sampling. Samples were collected nationwide from manufacturers and processors (9.9 percent), distributors and warehouses (16.5 percent), and retail operations (73.6 percent).
To increase the probability of detecting pathogens when their presence is low or not uniformly distributed, 10–30 subsamples were collected per sample, all from the same lot. Each subsample included one container weighing at least 8 ounces, and the agency collected a total of approximately 11,400 subsamples.
FDA detected Salmonella Havana in one sample of hummus collected from a retail establishment in California, and Listeria monocytogenes in three multi-commodity samples (two cheese samples and one cheese and pepper sample) collected from a retail establishment in Colorado. All three of the samples contaminated by L. monocytogenes were produced by the same manufacturer. Using whole genome sequencing (WGS), FDA determined that none of the Salmonella or L. monocytogenes isolated from the contaminated samples matched any clinical, product, or environmental samples.
FDA worked with manufacturers to remove contaminated products from the market. The agency also submitted the WGS findings for the pathogenic Salmonella and L. monocytogenes strains to the national GenomeTrakr database.
Based on its findings FDA, emphasizes the importance of food business operators adhering to Good Manufacturing Practices (GMPs), Hazards Analysis and Critical Control Points (HACCP), and the Risk-Based Preventive Controls for Human Food Rule. The agency warns that the risk of contamination persists, citing the 22 recalls of dips and spreads due to potential Salmonella or L. monocytogenes contamination in 2017–2022.