| Clinical
Features |
Watery or bloody diarrhea, abdominal
cramps, with or without fever. |
| Etiologic
Agent |
Escherichia coli of many
different serotypes, categorized into four major groups according
to virulence mechanisms: enterotoxigenic (ETEC); enteropathogenic
(EPEC); enteroinvasive (EIEC); and enteroaggregative (EAgg
EC). Other groups (e.g., diffusely adherent E. coli)
are less well established as pathogens. |
| Incidence |
Unknown; very few laboratories
can identify these organisms. Enterotoxigenic E. coli are
the most common cause of travelers’ diarrhea and have caused
several foodborne outbreaks in the United States. There are
an estimated 79,420 cases of ETEC in the United States each
year. EPEC and EIEC primarily infect children in the developing
world. Enteroaggregative E. coli probably cause chronic
diarrhea in HIV-infected patients. |
| Sequelae |
Sequelae of ETEC, EPEC, and EIEC
infection are not well described. Enteroaggregative E.
coli may cause chronic diarrhea. |
| Transmission |
Through food or water contaminated
with human or animal feces. Person-to-person transmission
may also occur, but is likely to be less common. |
| Risk
Groups |
International travelers are at
greatest risk for ETEC infection, while EPEC and EIEC are
most common among young children in the developing world.
EAggEC are most common among immunocompromised persons. |
| Surveillance |
There is no formal surveillance
system for diarrheogenic E. coli and most laboratories
are unable to identify them. |
| Trends |
Apparent steady increase in domestic
ETEC outbreaks. ETEC are increasingly resistant to available
antimicrobial agents, and this is likely true for EPEC, EIEC,
and EAggEC as well. |
| Challenges |
Improve surveillance by transferring
the techniques for identification and serotyping diarrheogenic
E. coli to public health and clinical laboratories.
Better understand the molecular genetics of the diverse virulence
mechanisms of these organisms and thereby develop tools to
enable more rapid detection of emerging diarrheogenic E.
coli strains. |
| Opportunities |
Improve surveillance of new and
emerging diarrheogenic E. coli strains through studies
of sporadic or outbreak-associated cases of diarrhea of unknown
etiology. Measure the effect of non-vaccine interventions
to prevent diarrheal disease on the incidence of infections
caused by diarrheogenic E. coli through collaborative
intervention studies. |
|
December 2003
|
