Food Safety and Inspection Service

U.S. DEPARTMENT OF AGRICULTURE

FSIS Foodborne Illness 

Outbreak Investigations, 

Fiscal Year 2023 

Introduction

The U.S. Department of Agriculture’s Food Safety and Inspection Service (FSIS), Office of 

Public Health Science, Applied Epidemiology Staff, coordinates the FSIS response to 

foodborne illness outbreaks that may involve FSIS-regulated products. This includes outbreaks 

that involve four foodborne pathogens that most frequently contaminate FSIS-regulated 

products: Salmonella, Shiga toxin-producing Escherichia coli (STEC), Listeria monocytogenes, 

and Campylobacter. A foodborne outbreak occurs when two or more persons experience a 

similar illness after ingestion of a common food, and epidemiologic analysis implicates the 

food as the source of the illness. FSIS may investigate illnesses associated with other, less 

common, foodborne pathogens (e.g., Clostridium botulinum) if they are potentially associated 

with FSIS-regulated products. 

FSIS collects and evaluates epidemiologic, laboratory, and traceback information to determine 

if there is an association between an FSIS-regulated product and human illnesses.

Epidemiologic information can include details like which foods ill people ate, where they 

purchased these foods, and where they live. Laboratory information can include comparing 

bacteria from FSIS samples and ill people to see if they are genetically similar or have similar 

characteristics. Traceback activities may include determining the location where the product 

was sold (e.g., grocery store, deli counter, or restaurant) or the source of a product (e.g., the 

federally inspected slaughter or processing facility). Depending on the evidence collected 

during an investigation, FSIS may have enough detailed exposure and product information to 

take one or more actions to prevent additional illnesses. These actions may include 

requesting that a company remove product from commerce and FSIS issuing a press release 

announcing that a firm is recalling meat, poultry, or egg products linked to human illnesses or

FSIS notifying the public of potential food safety concerns through the issuance of a Public 

Health Alert (PHA). 

This report summarizes outbreaks that FSIS investigated from October 1, 2022, to September 

30, 2023, Fiscal Year 2023 (FY 2023). This report also highlights key lessons learned from 

outbreak investigations in FY 2023. 
Fiscal Year 2023 in Review

During FY 2023, FSIS investigated six outbreaks in coordination with local, state, and federal 

public health partners. These outbreaks involved more than 100 illnesses and 30 

hospitalizations. The Centers for Disease Control and Prevention notified FSIS of five (83%) of 

these outbreaks. FSIS became aware of the sixth outbreak by notification from a state public 

health agency. Five (83%) outbreaks involved illnesses in more than one state. 

Of the six outbreaks investigated by FSIS in FY 2023, three were caused by Salmonella

(serotypes Newport, Saintpaul, and Typhimurium) and two by STEC (serogroup O157:H7). The 

sixth investigation involved a report of botulism that included commercially canned potted 

meat (containing chicken and pork) as a potential source (Figure 1). Given botulinum toxin’s 

potential to cause severe illness, FSIS investigates reports of one or more botulism cases that 

may be associated with FSIS-regulated products and includes those investigations in the 

Agency’s annual outbreak report. Beef products were the food product of interest for the five 

Salmonella and STEC outbreaks investigated in FY 2023 (Figure 2).

In FY 2023, outbreak investigations did not lead to any recalls of FSIS-regulated products or 

PHAs. FSIS may ask an establishment to voluntarily recall product from commerce to protect 

public health when the product is found to be associated with an outbreak. A recall is a firm’s 

removal of distributed meat, poultry, or egg products from commerce when there is a reason 

to believe that such products are adulterated or misbranded under the provisions of the 

Federal Meat Inspection Act, the Poultry Products Inspection Act, or Egg Products Inspection 

Act. FSIS may issue a PHA when the Agency determines that a meat, poultry, or egg product 

may be associated with human illness, but no adulterated product remains in commerce. FSIS 

may also issue a PHA when the Agency is unable to determine what specific regulated product 

is implicated by the illnesses and thus adulterated. 

* FSIS investigated a case of suspected foodborne 

botulismthat was later determined to not be caused

by a food source

0

1

2

3

4

5

Salmonella STEC Clostridium

botulinum*

Number of Outbreaks

Pathogen

Figure 1. FY 2023 Outbreaks by 

Pathogen (N = 6)

+ Product investigated was canned potted meat 

(containing chicken and pork)

0

1

2

3

4

5

6

Number of Outbreaks

Beef Multi-ingredient+

Commodity

Figure 2. FY 2023 Outbreaks by 

Product of Interest (N = 6)
Table 1 depicts characteristics of outbreaks investigated in FY 2023, including information on 

the serotype/serogroup, product of interest, and whether FSIS or non-FSIS samples were 

genetically related to human illnesses. While investigating outbreaks is crucial to protect 

public health, it is important to note that outbreak-associated illnesses represent a very small 

proportion of all foodborne illnesses. Consumers who are sick with a foodborne illness may 

not seek medical care or be tested for foodborne pathogens. Those that are tested may not 

be linked to other similar illnesses to initiate an outbreak investigation.

Table 1. FY 2023 Outbreak Characteristics 

Pathogen Serotype/

Serogroup CommodityA FSIS IsolatesB

Non-FSIS 

IsolatesC RecallD PHAE 

Salmonella

Newport Beef No Yes No No

Saintpaul Beef Yes No No No

Typhimurium Beef Yes Yes No No

STEC

O157:H7 Beef No No No No

O157:H7 Beef No No No No

Clostridium 

botulinum+

Multiingredient++ No No No No

A) Product investigated by FSIS as possible, likely, or confirmed cause of illnesses during investigation.

B) Isolates recovered from FSIS testing (product, cecal, or environmental) found to be related by whole genome 

sequencing or another testing method to outbreak clinical isolates.

C) Isolates recovered from non-FSIS testing (product, live animal, or environmental) found to be related by 

whole genome sequencing to outbreak clinical isolates.

D) Based on available evidence, FSIS-regulated product was determined to be the cause of human illnesses and 

an FSIS-regulated establishment recalled product from commerce.

E) Based on available evidence, FSIS-regulated product poses a public health risk; however, the product is no 

longer available for sale in commerce or FSIS is unable to determine which specific product is adulterated or 

misbranded and FSIS issued a PHA to notify the public. 

+) Investigation of a case of suspected foodborne botulism; illness was later determined to not be associated 

with a food source. 

++) The product investigated was canned potted meat (containing chicken and pork). 

Learning from Outbreaks

Analysis of outbreaks associated with FSIS-regulated products is crucial to FSIS’ mission to 

prevent foodborne illness and to protect public health. FSIS conducts after action reviews 

(AAR) at the conclusion of foodborne outbreak investigations to identify lessons learned 

that can help improve response and prevent future illnesses. Applying and sharing outbreak 

lessons learned may lead to improved food safety policies and can strengthen collaborative 

investigations with public health partners. Below are highlights from AARs conducted during 

FY 2023. 

In FY 2023, FSIS investigated several outbreaks potentially associated with ground beef, 

including beef ground and packaged at retail stores. Ground beef produced in retail stores can 
complicate investigations if retail records do not clearly identify the specific suppliers of beef 

that were ground and later purchased by ill people. Retailers that grind are required to keep 

records for all ground beef produced in-store. These records are crucial for investigators to 

identify potentially contaminated product(s) that may be linked to an outbreak and for FSIS to 

take action to prevent additional illnesses.

FSIS investigated a Clostridium botulinum illness potentially associated with canned potted

meat (containing chicken and pork). FSIS’ investigation of the establishment where the canned 

potted meat was produced, and laboratory testing of similar cans, did not determine that the 

canned potted meat was the source of the illness. The illness was later determined to not be 

associated with a food source. This investigation highlights the importance of a quick response 

and good collaboration between state and federal public health partners involving an 

uncommon bacterium (C. botulinum). Continuing to foster relationships with public health 

partners will enable FSIS to continue to quickly respond to potential outbreaks in the future. 

To learn more about outbreaks and see examples of how FSIS has applied outbreak lessons 

learned toward illness prevention, visit the FSIS Outbreaks webpage.