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Cause:
Shiga toxin-producing E. coli strains (STEC) including E. coli O157:H7.
Illness and treatment:
Symptoms include abdominal cramping and severe or
bloody diarrhea, usually without fever. Serious
complications include hemolytic uremic syndrome (HUS) or
thrombotic thrombocytopenic purpura (TTP). Most persons will
recover without treatment. Treating EHEC diarrhea with
antibiotics may increase the risk of developing HUS.
Sources:
Cattle are the most important source, although other herbivores may also carry EHEC.
Other known sources are unpasteurized milk, undercooked ground beef and contaminated
raw produce. There can be person-to-person and animal-to-person transmission, but most
cases are due to ingesting contaminated food or water.
Additional risks:
Children under 5 years of age are diagnosed most frequently and are at the greatest
risk of developing HUS.
Prevention:
Wash hands thoroughly after contact with farm animals, visiting farm environments, and
handling raw meat. Thoroughly cook ground beef and venison and wash preparation areas
to avoid contaminating other foods. Wash produce thoroughly before eating.
Recent Washington trends:
For the past several years there have been about 130 - 200 reports
each year. EHEC has a seasonal pattern. Most cases occur during summer and fall months.
2010:
A total of 226 EHEC cases were reported (rate 3.4 cases/100,000 population);
12 reported HUS as a complication. Among 186 confirmed cases only 110 (59%)
were serogroup O157. A recent substantial rate increase for non-O157 EHEC
(1.1 in 2010 vs. 0.5 in 2009) reflects new laboratory testing practices. The 76
non-O157 EHEC infections included 45 serogroup O26, 12 O103, 6 O121, and 3
each O111 and O45, and ≤ 2 cases each included O118, O145, O126, O174, and O178.
Purpose of Reporting and Surveillance
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To determine if there is a source of infection of public health concern (e.g.,
contaminated ground beef) and to stop transmission from such a source.
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When the source of infection appears to pose a risk to only a few individuals
(e.g., a private water supply), to inform those individuals how they can
reduce their risk of exposure.
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To assess the risk of the case transmitting infection to others, and to prevent such transmission.
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To identify outbreaks and other undiagnosed cases.
Legal Reporting Requirements
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Health care providers:
immediately notifiable to local health jurisdiction
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Health care facilities:
immediately notifiable to local health jurisdiction
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Laboratories:
Shiga toxin-producing E. coli (enterohemorrhagic E. coli including,
but not limited to, E. coli O157:H7) and Shiga-toxin positive stool assays
immediately notifiable to local health jurisdiction; submission of stool specimen
or isolate to the Washington State Department of Health (DOH) Public Health Laboratories
(PHL) is required (2 business days)
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Veterinarians:
Suspected human cases immediately notifiable to the local health jurisdiction;
animal cases may be notifiable to Washington State Department of Agriculture (see:
http://apps.leg.wa.gov/WAC/default.aspx?cite=16-70.)
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Local health jurisdictions:
notifiable to DOH Communicable Disease Epidemiology (CDE) within 7 days of case
investigation completion or summary information required within 21 days
Last update
December 2011 |
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