Non-O157 Shiga toxin-producing Escherichia coli infections in the United States, 1983-2002.
BACKGROUND
Shiga toxin-producing Escherichia coli (STEC) O157:H7 is a well-recognized cause of bloody diarrhea and hemolytic-uremic syndrome (HUS). Non-O157 STEC contribute to this burden of illness but have been underrecognized as a result of diagnostic limitations and inadequate surveillance.


METHODS
Between 1983 and 2002, 43 state public health laboratories submitted 940 human non-O157 STEC isolates from persons with sporadic illnesses to the Centers for Diseases Control and Prevention reference laboratory for confirmation and serotyping.


RESULTS
The most common serogroups were O26 (22%), O111 (16%), O103 (12%), O121 (8%), O45 (7%), and O145 (5%). Non-O157 STEC infections were most frequent during the summer and among young persons (median age, 12 years; interquartile range, 3-37 years). Virulence gene profiles were as follows: 61% stx(1) but not stx(2); 22% stx(2) but not stx(1); 17% both stx(1) and stx(2); 84% intimin (eae); and 86% enterohemolysin (E-hly). stx(2) was strongly associated with an increased risk of HUS, and eae was strongly associated with an increased risk of bloody diarrhea. STEC O111 accounted for most cases of HUS and was also the cause of 3 of 7 non-O157 STEC outbreaks reported in the United States.


CONCLUSIONS
Non-O157 STEC can cause severe illness that is comparable to the illness caused by STEC O157. Strains that produce Shiga toxin 2 are much more likely to cause HUS than are those that produce Shiga toxin 1 alone. Improving surveillance will more fully elucidate the incidence and pathological spectrum of these emerging agents. These efforts require increased clinical suspicion, improved clinical laboratory isolation, and continued serotyping of isolates in public health laboratories.
Brooks
John T
JT
Foodborne and Diarrheal Diseases Branch, Division of Bacterial and Mycotic Diseases, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA. zud4@cdc.gov
Sowers
Evangeline G
EG
Wells
Joy G
JG
Greene
Katherine D
KD
Griffin
Patricia M
PM
Hoekstra
Robert M
RM
Strockbine
Nancy A
NA
D004196:Disease Outbreaks / Q000706:statistics & numerical data; D004926:Escherichia coli / Q000737:chemistry* / Q000145:classification / Q000472:pathogenicity; D004927:Escherichia coli Infections / Q000453:epidemiology*; D006801:Humans; D012703:Serotyping; D022603:Shiga Toxins / Q000096:biosynthesis* / Q000235:genetics; D013997:Time Factors; D014481:United States / Q000453:epidemiology; D014774:Virulence
D022603:Shiga Toxins