Human Escherichia coli O121 Infections Linked to Multiple Frozen Snack Foods — United States, 2013

Bosch, Stacey

Tuesday, June 24, 2014: 10:40 AM

102, Nashville Convention Center

Stacey Bosch , Centers for Disease Control and Prevention, Atlanta, GA

Tara C Anderson , Centers for Disease Control and Prevention, Atlanta, GA

Jeshua Pringle , Centers for Disease Control and Prevention, Atlanta, GA

Sung Im , Centers for Disease Control and Prevention, Atlanta, GA

Madhu Anand , New York State Department of Health, Albany, NY

Timothy Root , New York State Department of Health, Albany, NY

Venessa Cantu , Texas Department of State Health Services, Austin, TX

Stelios Viazis , Food and Drug Administration, College Park, MD

Jennifer Beal , Food and Drug Administration, College Park, MD

Angela M. Hardin , Food and Drug Administration, College Park, MD

Alyssa Clendenin , Food and Drug Administration, College Park, MD

Susan Lance , Food and Drug Administration, Atlanta, GA

Alice Green , U.S. Department of Agriculture, Minneapolis, MN

Bonnie Kissler , U.S. Department of Agriculture, Atlanta, GA

Matthew Wise , Centers for Disease Control and Prevention, Atlanta, GA

BACKGROUND: Shiga toxin-producing Escherichia coli(STEC) infections cause an estimated 175,000 illnesses, 2,400 hospitalizations, and 20 deaths annually in the United States. In February 2013, PulseNet, the national bacterial subtyping network for foodborne disease surveillance, identified a cluster of human infections with a previously unreported strain of STEC O121.

METHODS: A case was defined as illness in a person infected with the STEC O121 outbreak strain determined by pulsed field-gel electrophoresis with illness onsets between December 1, 2012 and May 13, 2013. We collected information on patients’ exposures using questionnaires and open-ended iterative interviews. Public health and regulatory agencies collaborated to culture leftover foods and conduct traceback investigations.

RESULTS: We identified 35 cases in 19 states. Illness onsets ranged from December 30, 2012 through April 15, 2013. The median patient age was 17 years (range: 1–75 years); 60% were female. Among 29 patients with available information, 9 (31%) were hospitalized. Twenty-four (100%) of 24 patients reported eating multiple frozen foods in the week before illness; 13/19 (68%) ate Brand A frozen snack foods produced at a single facility. The outbreak strain was isolated from two leftover Brand A heat-treated, not-fully-cooked frozen foods collected from patients’ homes in New York and Texas, leading to product recalls totaling >10.5 million pounds of frozen snack foods. FDA investigated common product ingredients, including flour, but did not identify the outbreak strain at either the snack food or flour production facilities.

CONCLUSIONS: A novel vehicle for STEC O121, frozen snack foods, was identified using an open-ended iterative interviewing approach combined with targeted product testing. Collaborations between public health and regulatory officials were key to identifying the outbreak vehicle and resulted in multiple recalls, preventing further illness. Food manufacturers should consider flour as a potential STEC source.