E. coli Outbreak: What Have We Learned Since 1993?

They say, “Those who cannot remember the past are condemned to repeat it.”

And that is the very thing the Centers for Disease Control and Prevention (CDC) is hoping to remind public health specialists—and, likely, state and federal legislators as well as the media—through its “We Were There” series, which includes events featuring speakers and multimedia presentations highlighting the agency’s role during several key disease outbreaks in the 20th and 21st centuries. The CDC launched the series in 2016.

The latest “We Were There” program, held at the CDC’s Atlanta headquarters on May 25th, focused on the agency’s work on the infamous Escherichia coli (E. coli) outbreak of 1993. The outbreak, which was traced to hamburgers sold by the fast-food chain Jack-in-the-Box, yielded 744 cases, most of them children. Of these, 193 were hospitalized as a result of their illnesses; 56 developed kidney failure as a result of hemolytic uremic syndrome (HUS)—linked with the specific E. coli strain implicated in the outbreak; and 4 deaths.

Speakers at the event included Rima Khabbaz, MD, CDC Deputy Director for Infectious Diseases; Beth P. Bell, MD, MPH, former director, National Center for Emerging and Zoonotic Infectious Diseases; Bala Swaminathan, PhD, Executive Vice-President, IHRC and a former CDC lab scientist; Robert Tauxe, MD, Director, Division of Foodborne, Waterborne and Environmental Diseases, National Center for Emerging and Zoonotic Infectious Diseases; and Patricia M. Griffin, MD, Chief, CDC Enteric Diseases Epidemiology Branch. These and other clinicians and researchers working for the CDC at the time were involved in the publication of several landmark studies associated with the outbreak, including the case-control study published in the Journal of the American Medical Association and the article that highlighted the need for improved lab testing, published in the American Journal of Public Health.

What made the 1993 initially difficult to identify and control, of course, was the fact that its cause was a relatively little known strain of E. coli called 0157. At the time of the outbreak, which was first reported in Seattle on January 12, 1993, Dr. Griffin noted that only 6% of US labs were able to test for, and identify, 0157, and food safety standards governing both production and preparation were insufficient to protect the public from illness.

“The outbreak drove a shift in food safety that the CDC had been working toward for years,” noted Dr. Griffin during the event. This shift included new standards for proper handling and cooking of food eventually enacted by the US Food and Drug Administration (FDA) and the US Department of Agriculture (USDA) in the aftermath of the outbreak, as well as several CDC initiatives. “And it was a mandate for improved [food-borne disease] surveillance throughout the United States,” she added.

As cases related to 0157 were identified in San Diego County, California and Las Vegas, Nevada later in January 1993, CDC scientists were able to trace the source of the pathogen to a single lot of 255,000 pounds of beef produced in November 1992. The subsequent voluntary recall of beef supplies initiated by Jack-in-the-Box at the CDC’s urging on January 18, 1993 prevented more than 800 additional cases, the agency’s research suggests. It is worth noting that the CDC believes that the fast-food chain was “cooperative” in the aftermath of the outbreak, and that it was recognized with the Black Pearl Award for food safety, as a result of changes it instituted at the time, in 2004.

As tragic as the outbreak was for those who were affected, it did lead to important innovations in food safety and outbreak response. In addition to the new standards imposed by the FDA and USDA, the CDC launched 2 new programs as a result of the outbreak: FoodNet, the Food-Borne Diseases Active Surveillance Network launched in 1995 to assist in the identification of outbreaks of Campylobacter, Cryptosporidium, Cyclospora, Listeria, Salmonella, Shiga toxin-producing E. coli (STEC) O157 and non-O157, Shigella, Vibrio, and Yersinia infections, and PulseNet, a lab network designed to detect food-borne illnesses and link them to possible outbreaks, which was launched in 1996. However, despite the importance of these “big picture” projects, Dr. Bell told the audience that the 1993 outbreak also served as a reminder of the importance of vigilance and proactive response at the grassroots level.

“All public health is local,” she said. “All of us at CDC know that we need strong state and local public health [departments] to do our work.”

Brian P. Dunleavy is a medical writer and editor based in New York. His work has appeared in numerous healthcare-related publications. He is the former editor of Infectious Disease Special Edition.