An Investigation of a Multistate Outbreak of Shiga Toxin-Producing Escherichia coli O121:H19 Infections Linked to Frozen Falafel – United States, 2022

In 2022, an outbreak of Shiga toxin-producing Escherichia coli (STEC) O121:H19 infections was identified, including 24 ill people in six states. Illnesses were identified through PulseNet, and food histories were collected by state public health partners. Among those interviewed, 18 (86%) reported purchasing food from Grocery Chain A, and fourteen (78%) of those shoppers reported consuming frozen falafel prior to becoming ill. The manufacturing firm issued a recall on December 7, 2022, within 24 hours of learning about the outbreak. State partners in Michigan and Ohio collected product samples from ill patients’ homes. An open product sample collected by Michigan partners yielded the outbreak strain. Food and Drug Administration (FDA) collected 14 samples: three ingredients (ground coriander, dill, and red pepper) and 11 finished product samples; all were negative for STEC. The product was par-fried for functionality, was not sold as ready-to-eat, and included cooking instructions to heat to 165°F. This was the first STEC outbreak linked to frozen falafel in the United States. Despite the instructions, consumers may deem such a vegan product as safe to consume undercooked. It is important for food manufacturers to assess their products and processing to implement controls that adequately mitigate microbial hazards.