| Clinical
Features |
Acute bloody diarrhea and abdominal
cramps with little or no fever; usually lasts 1 week. |
| Etiologic
Agent |
Escherichia coli serotype
O157:H7. Gram-negative rod-shaped bacterium producing Shiga
toxin(s). |
| Incidence |
An estimated 73,000 cases occur
annually in the United States. Uncommonly reported in patients
in less industrialized countries. |
| Sequelae |
Hemolytic uremic syndrome (HUS):
Persons with this illness have kidney failure and often require
dialysis and transfusions. Some develop chronic kidney failure
or neurologic impairment (e.g., seizures or stroke). Some
have surgery to remove part of the bowel. Estimated 61 fatal
cases annually; 3-5% with HUS die. |
| Costs |
Estimated 2,100 hospitalizations
annually in the United States. The illness is often misdiagnosed;
therefore, expensive and invasive diagnostic procedures may
be performed. Patients who develop HUS often require prolonged
hospitalization, dialysis, and long-term follow-up. |
| Transmission |
Major source is ground beef; other
sources include consumption of unpasteurized milk and juice,
sprouts, lettuce, and salami, and contact with cattle. Waterborne
transmission occurs through swimming in contaminated lakes,
pools, or drinking inadequately chlorinated water. Organism
is easily transmitted from person to person and has been difficult
to control in child day-care centers. |
| Risk
Groups |
All persons. Children <5 years old
and the elderly are more likely to develop serious complications.
|
| Surveillance |
E. coli O157:H7 infection
is nationally reportable and is reportable in most U.S. states.
HUS is also reportable in most states. |
| Trends |
Since the first description of
this illness in 1982, infections have been reported from >30
countries on six continents. The use of subtyping by pulsed-field
gel electrophoresis and comparison of patterns by PulseNet
has increased the ability to identify outbreaks. |
| Challenges |
Developing farm and slaughterhouse-based
methods to decrease contamination of meat; encouraging use
of irradiation to increase the safety of ground beef; identifying
ways to prevent contamination of foods eaten raw (e.g., produce);
educating the U.S. public to cook ground beef thoroughly,
preferably using a digital instant-read thermometer; convincing
clinical laboratories to screen for E. coli O157:H7
in stools from persons with bloody diarrhea; conducting population-based
surveillance for HUS and determining which serotype of Shiga
toxin-producing E. coli was responsible for illness;
identifying other vehicles of transmission; developing an
international network for subtyping and communicating about
outbreaks. |
| Opportunities |
Learning more about the ecology
of this organism in cattle and other ruminants may help in
devising methods to decrease its prevalence in food animals.
Learning how this pathogen contaminates produce items could
lead to measures that would increase their safety. Decreasing
the incidence of these infections would decrease HUS, the
major cause of kidney failure in children in the United States.
Transmission in day-care centers highlights need for better
infection-control practices. |
|
December 2000
|
