The U.S. Department of Agriculture’s Food Safety and Inspection Service (USDA’s FSIS) has published two reports on its foodborne illness outbreak investigations and sampling activities for fiscal year (FY) 2022 (spanning October 1, 2021–September 30, 2022).

Foodborne Illness Outbreak Investigations

For FSIS-regulated products suspected to be the vehicle of human illness, the agency collects and evaluates epidemiologic, laboratory, and traceback information to determine if there is an association. Most commonly, FSIS investigates foodborne illness outbreaks involving Salmonella, Shiga toxin-producing Escherichia coli (STEC), Listeria monocytogenes, and Campylobacter.

During FY 2022, FSIS investigated seven outbreaks in coordination with local, state, and federal public health partners. The outbreaks included approximately 120 illnesses and 30 hospitalizations. The U.S. Centers for Disease Control and Prevention (CDC) notified FSIS of six (86 percent) of these outbreaks, and FSIS became aware of the seventh outbreak by notification from a state public health agency. A total of five outbreaks (71.4 percent) were multi-state.

Of the seven outbreaks investigated by FSIS in FY 2022, Salmonella and STEC each caused three outbreaks. The seventh investigation involved a case of Clostridium botulinum infection where FSIS investigated commercially canned soup as a potential source. The three Salmonella outbreaks investigated involved chicken, beef, and pork products, as well as serotypes Enteritidis; Muenchen; and I 4,[5], 12: i-. The three STEC outbreaks were all caused by serogroup O157:H7, and beef was the most commonly implicated food product.

FSIS conducts after-action reports to assess foodborne illness outbreaks caused by FSIS-regulated products and identify lessons that can help improve response and prevent illnesses in the future. For example, the agency highlighted two Salmonella outbreaks linked to Italian-style meats revealing factors that may have caused contamination, such as the use of a reduced salt formulation and lack of validated scientific support to achieve a 5-log reduction in Salmonella. A 5-log reduction in Salmonella means that processing will result in a 99.999 percent reduction of the pathogen that may be present in the raw meat, spices, and other ingredients used to make salami. FSIS determined that a 5-log reduction of Salmonella in shelf-stable products like salami will result in a safe product, and the agency is working with research partners to fill data gaps and better identify support for the safety of Italian-style meats.

The report also underlines lessons learned from the investigation of a C. botulinum illness potentially associated with commercially canned soup. Due to the outbreak potential of C. botulinum and the severity of illness, FSIS investigates reports of one or more botulism illnesses that may be associated with FSIS-regulated products and includes those investigations in the annual outbreak report. Botulinum toxin type A was identified in both the patient and an empty soup can collected from the kitchen trash can in the patient’s home. FSIS’ investigation of the establishment where the soup was produced, including laboratory results of similar cans tested, did not confirm that the soup was the source of the illness. The botulism case appears to have been an isolated incident and emphasizes the importance of public awareness regarding hazards associated with eating food from damaged or dented cans. The investigation also highlights the importance of a quick response and good collaboration between state and federal public health partners involving uncommon bacteria like C. botulinum.

Annual Sampling Summary Report

FSIS inspects meat, poultry, and egg products to ensure that the food produced is safe, wholesome, and properly labeled. The Annual Sampling Summary Report summarizes the activities and provides an overview of results for the products FSIS sampled during FY 2022, following the agency’s Annual Sampling Plan, which describes FSIS’ overall strategy for directing its sampling resources. Types of sampling included in the report are domestic microbiological sampling, domestic chemical residue sampling, microbiological and chemical residue sampling for imports, and miscellaneous other kinds of sampling to determine food authenticity. The report also highlights FSIS’ whole genome sequencing (WGS) –related initiatives and sampling under the National Antimicrobial Resistance Monitoring System (NARMS).

FSIS laboratories perform WGS on all positive sample isolates for all pathogens from FSIS-regulated products, and in FY 2022, this equated to 16,193 bacterial isolate sequences, which were uploaded to the National Center for Biotechnology Information (NCBI). Additionally, in May 2022, FSIS updated its publicly available, establishment-specific datasets to include the FSIS number and date-stamped allele codes, thereby providing a way to link FSIS sequence metadata sequence data that is already publicly available on NCBI and enabling discrete reportable results for comparing FSIS isolates to each other.

NARMS is an interagency collaborative partnership with state and local public health departments, the U.S. Food and Drug Administration (FDA), CDC, and USDA. This national public health surveillance system tracks changes in antimicrobial susceptibility of select foodborne enteric bacteria found in ill people (CDC), retail meats (FDA), and food animals (FSIS).