E coli and Food Safety: It's a Jungle Out There

William F. Balistreri, MD


April 23, 2018

In This Article

Foodborne illnesses are a substantial yet largely preventable health burden worldwide. We previously reviewed food safety in the United States[1] and harked back to the classic book, The Jungle, which portrayed the unsanitary conditions and practices prevalent in industrialized American cities in the early 1900s.[2] While this had a significant impact on reformation of the meatpacking industry, how far have we come since the conditions reported by Upton Sinclair? One indicator of progress is whether we have adequately responded to the lessons learned. In this context, we will focus specifically on foodborne Escherichia coli infections.

E coli Outbreaks and Renewed Efforts for Safety

In 1993, an E coli outbreak in four states affected more than 700 people and was associated with 171 hospitalizations, including four deaths in children, attributed to hemolytic-uremic syndrome (HUS); the common source of their illnesses was traced to Shiga toxin–producing E coli (STEC) serogroup O157–contaminated hamburgers sold at Jack in the Box restaurants.[3,4]

This dramatic, widely publicized case series served to increase public awareness and concern about unsanitary practices in the fast-food industry.[5] That outbreak, in part, spurred significant improvements in efforts to ensure safe food, including enhanced federal food safety regulations, more stringent industry practices, and intensified policies by the Centers for Disease Control and Prevention (CDC), the US Department of Agriculture (USDA), and the US Food and Drug Administration (FDA).[6] This has been accompanied by advances in food science and by more rapid and precise pathogen detection, food monitoring, and surveillance.[7,8,9]

Key efforts to improve food safety have included the following[6]:

  • E coli O157:H7 was declared an adulterant in ground beef, and other non-O157 STECs have been added to the list of adulterants;

  • E coli O157:H7 was raised to reportable disease status at all state health departments;

  • The CDC developed pulsed-field gel electrophoresis (PFGE) to detect and track bacterial isolates; PulseNet became the national molecular subtyping network for foodborne disease surveillance[8,10];

  • Research was undertaken to determine ways to reduce E coli in cattle and slaughterhouses;

  • Testing for E coli O157:H7 in ground beef was initiated;

  • Consumer education programs about potential dangers in ground beef and instructions for safe handling and optimal cooking were created;

  • The recommended temperature for cooking ground beef was increased by the FDA; and

  • Safe production facilities via the USDA Food Safety and Inspection Service (FSIS) and the Hazard Analysis and Critical Control Point (HACCP) were ensured.[11]

Infections caused by E coli serogroup O157 declined after targeted interventions to reduce contamination of ground beef were implemented.[8] So, where do we stand in regard to food safety policy and in the detection and prevention of illness due to E coli in the United States?

We will specifically review the history of infection due to STEC O157:H7; however, we will also discuss serogroups of STEC other than serogroup O157 (eg, STEC O26:H11), which are highly pathogenic, capable of causing HUS, and have been associated with foodborne bacterial gastrointestinal illnesses and outbreaks in the United States.[9,12,13,14]

Food Safety Policy: Where Do We Stand?

The Foodborne Diseases Active Surveillance Network (FoodNet) conducts active, population-based surveillance at 10 US geographic areas sites for laboratory-confirmed infections commonly transmitted through food and monitors trends in enteric illnesses and identifies their sources. According to FoodNet, the incidence of STEC O157 declined in 2014 compared with previous survey years.[13,15,16] However, despite ongoing food safety efforts, the incidence of infection remains high, indicating that further prevention measures are needed to make food safer and to achieve national health objectives.


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