Epidemiology of Escherichia coli O157:H7 Outbreaks, United States, 1982-2002

Josefa M. Rangel; Phyllis H. Sparling; Collen Crowe; Patricia M. Griffin; David L. Swerdlow


Emerging Infectious Diseases. 2005;11(4):603-609. 

In This Article

Abstract and Introduction

Escherichia coli O157:H7 causes 73,000 illnesses in the United States annually. We reviewed E. coli O157 outbreaks reported to Centers for Disease Control and Prevention (CDC) to better understand the epidemiology of E. coli O157. E. coli O157 outbreaks (≥2 cases of E. coli O157 infection with a common epidemiologic exposure) reported to CDC from 1982 to 2002 were reviewed. In that period, 49 states reported 350 outbreaks, representing 8,598 cases, 1,493 (17%) hospitalizations, 354 (4%) hemolytic uremic syndrome cases, and 40 (0.5%) deaths. Transmission route for 183 (52%) was foodborne, 74 (21%) unknown, 50 (14%) person-to-person, 31 (9%) waterborne, 11 (3%) animal contact, and 1 (0.3%) laboratory-related. The food vehicle for 75 (41%) foodborne outbreaks was ground beef, and for 38 (21%) outbreaks, produce.

Escherichia coli O157:H7 was first recognized as a pathogen in 1982 during an outbreak investigation of hemorrhagic colitis.[1]E. coli O157 infection can lead to hemolytic uremic syndrome (HUS), characterized by hemolytic anemia, thrombocytopenia, and renal injury.[2] Still, it was not until 1993, after a large multistate E. coli O157 outbreak linked to undercooked ground beef patties sold from a fast-food restaurant chain,[3] that E. coli O157 became broadly recognized as an important and threatening pathogen. Clinical laboratories began examining more stool specimens for E. coli O157.[4] In 1994, E. coli O157 became a nationally notifiable infection, and by 2000, reporting was mandatory in 48 states. An estimated 73,480 illnesses due to E. coli O157 infection occur each year in the United States, leading to an estimated 2,168 hospitalizations and 61 deaths annually,[5] and it is an important cause of acute renal failure in children.[6,7]

Although reported outbreaks account for only a minority of E. coli O157 cases, outbreak investigations contribute greatly to understanding E. coli O157 epidemiology by identifying transmission routes, vehicles, and mechanisms of contamination.[8] Outbreak findings oblige regulatory and public health agencies and industry to evaluate prevention and control measures so similar outbreaks can be prevented. Knowledge of transmission routes and vehicles allows consumers to be educated on reducing risky behavior that can decrease their risk for infection. We report here surveillance results for E. coli O157 outbreaks reported to the Centers for Disease Control and Prevention (CDC) from 1982 through 2002, to highlight the epidemiology of this emerging pathogen.