Notice to Health Care Providers: Shiga Toxin-producing E. coli cases in Spartanburg County
The South Carolina Department of Health and Environmental Control (DHEC) is requesting heightened surveillance for persons presenting with symptoms consistent with Shiga toxin producing E. coli (i.e., enterohemorrhagic E. coli), including diarrhea that is often bloody, hemolytic uremic syndrome (HUS) in children or thrombocytopenia purpura in adults.
Summary
DHEC is investigating an outbreak of Shiga toxin-producing Escherichia coli (STEC) related to dining at a Spartanburg-area Mexican restaurant during the last week of April, 2012. Preliminary lab results indicate the E. coli serotype being O157:H7. Of the 3 cases interviewed thus far, two reported the infection has progressed to hemolytic uremic syndrome (HUS), a severe condition associated with STEC infection that can lead to kidney failure. Interviews with an additional 8 cases are in progress.
Guidance for Clinicians
Symptoms
DHEC recommends a high index of suspicion for STEC infection for patients presenting with STEC symptoms and a history of dining at a Spartanburg- area Mexican restaurant near the end of April, 2012.
Clinical syndromes associated with a Shiga toxin producing E. coli infection include
Gastroenteritis with diarrhea and abdominal cramps (fever and bloody stools may or may not be present), and/or Hemolytic uremic syndrome (HUS) with or without gastroenteritis, which typically develops a week after the onset of diarrhea. Hemolytic uremic syndrome (HUS) is characterized by the triad of acute onset of microangiopathic hemolytic anemia, renal injury, and low platelet count. Most cases of HUS occur after an acute gastrointestinal illness (usually diarrheal). Management Management of STEC is typically supportive, as most patients recover within 5-7 days. Antibiotics for gastroenteritis are generally not recommended, as there have been reports of increased incidence of post-diarrheal HUS when antibiotics are used to manage STEC infections. The CDC does not recommend the use of antibiotics for patients with suspected STEC infections until complete diagnostic testing can be performed and STEC infection is ruled out. However, clinical decision making must be tailored to each individual patient. There may be indications for antibiotics in patients with severe intestinal inflammation if perforation is of concern.
Testing
• All stools submitted for testing from patients with acute community-acquired diarrhea should be cultured for STEC O157:H7. These stools should be simultaneously assayed for non-O157 STEC with a test that detects the Shiga toxins or the genes encoding these toxins.
• Clinical laboratories should report and send E. coli O157:H7 isolates and Shiga toxin- positive samples to the SC DHEC Bureau of Laboratories (BOL) as soon as possible for additional characterization.
• Specimens or enrichment broths in which Shiga toxin or STEC are detected, but from which O157:H7 STEC isolates are not recovered should be forwarded as soon as possible to the SC DHEC BOL so that non-O157:H7 STEC can be isolated.
• It is often difficult to isolate STEC in stool by the time a patient presents with HUS. Immunomagnetic separation (IMS) has been shown to increase recovery of STEC from HUS patients. For any patient with HUS without a culture-confirmed STEC infection, stool can be sent to the SC DHEC BOL for IMS or to the CDC (through the BOL). In addition, serum can be sent to CDC (through the BOL) for serologic testing of common STEC serogroups. The benefits of adhering to the recommended testing strategy include early diagnosis, improved patient outcome, and detection of all STEC serotypes. Reporting of Cases Cases of bloody diarrhea or a clinical presentation consistent with STEC, coupled with the epidemiologic criteria described above, should be reported to your local health department via the phone numbers listed below. DHEC will arrange for collection of stool samples for testing, as appropriate. Any laboratory confirmed acute case associated with Shiga toxin producing E. coli or E. coli identified as serogroup O157:H7 should be reported within 24 hours to DHEC, as per the current DHEC List of Reportable Conditions.
Resources for Additional Information
• CDC E. coli Investigation updates (www.cdc.gov/ecoli/2011/ecoliO104/index.html)
• CDC E. coli Resources for Clinicians (www.cdc.gov/ecoli/clinicians.htm)
• CDC E. coli General Information (http://www.cdc.gov/nczved/divisions/dfbmd/diseases/ecoli_157h7/)
• MMWR – “Recommendations for Diagnosis of Shiga Toxin–Producing Escherichia coli Infections by Clinical Laboratories” (www.cdc.gov/mmwr/PDF/rr/rr5812.pdf)
• WHO E. coli Investigation updates (www.who.int/csr/don/en/index.html)
• FoodSafety.gov (www.foodsafety.gov/) DHEC contact information for reportable diseases and reporting requirements Reporting of confirmed and suspected Shiga Toxin-producing E. coli cases is consistent with South Carolina Law requiring the reporting of diseases and conditions to your state or local public health department. (State Law # 44-29-10 and Regulation # 61-20) as per the DHEC 2011 List of Reportable Conditions available at: http://www.scdhec.gov/administration/library/CR-009025.pdf Federal HIPAA legislation allows disclosure of protected health information, without consent of the individual, to public health authorities to collect and receive such information for the purpose of preventing or controlling disease. (HIPAA 45 CFR §164.512).