Jun 28, 2017




Clinical Hub,Tools & Resources,UWHC Lab Test Directory,Microbiology

Escherichia coli (Shiga) Toxin

Escherichia coli (Shiga) Toxin (HCSTEC or as part of Stool Culture Order Panel (HCSTOCEC)) Microbiology Lab Test

Name: Escherichia coli (Shiga) Toxin

Test Name: Escherichia coli (Shiga) Toxin

Health Link Test Code: HCSTEC or as part of Stool Culture Order Panel (HCSTOCEC)

LIS Test Code: STEC

CPT Code(s): 87427

Methodology: Enzyme Immunoassay

Clinical Information:

Qualitative detection of Shiga toxins present in fecal specimens. Should be used as an aid in diagnosis of enterohemorrhagic E. coli infections. Routine ordering with Stool Culture is highly recommended.

Days Performed: Mon, Wed, and Fri.

In-Lab Turnaround Time: 1 - 3 days.

Stat In-Lab Turnaround Time: Not available stat.

Specimen: Stool

Collection Container: Para-PakĀ® Culture & Sensitivity (C & S) kit (orange cap)

Also Acceptable: Sterile screw cap container

Collection Instructions:

Pass stool into a clean, dry bedpan. Do not use toilet paper to collect stool. It may be impregnated with barium salts which may be inhibitory. Transfer stool to Para-Pak Culture & Sensitivity (C&S) kit (orange cap) or sterile screw cap container.

Collection Volume: 1 mL

Pediatric Collection Volume: 1 mL

Stability Ambient:

Preserved: 2 hours

Unpreserved: 2 hours

Stability Refridgerated:

Preserved: 7 days

Unpreserved: 48 hours

Stability Frozen:

Preserved: 7 days

Unpreserved: 48 hours

Sample Analyzed: Stool

Testing Volume: 0.3 mL

Pediatric Testing Volume: 0.3 mL

Specimen Transport:

Transport specimen to UWHC Microbiology Laboratory within 2 hours of collection. Refrigerate specimen if transport time will exceed 2 hours.

Unacceptable Criteria:

Unrefrigerated fresh stool greater than 48 hours old, unrefrigerated preserved stool specimens greater than 7 days old, and stool collected into O&P Para-pak® containers (pink and gray caps) are not acceptable. Specimens on patients hospitalized more than 3 days are not accepted.


LIMIT: One specimen every 24 hours.



Interpretation Type: Expected Results

Test Limitations:

Toxin level may be below the detection level of the test. Correlation between the amount of toxin in a sample and clinical presentation has not been established.

Additional Information:

Results should be interpreted by the clinician in conjunction with clinical findings and/or other laboratory results. Optimal results are obtained from specimens tested as soon after collection as possible.


Minimal degradation of toxins occurs in specimens that have been refrigerated for up to 48 hours or frozen at -20 degrees Celsius or lower immediately after collection.



For an Indeterminate result, another specimen should be obtained and retested.


Positive results are called to a health care provider.


Because these agents do not cause hospital acquired infection, specimens on patients who have been hospitalized greater than 3 days will require approval of the Director of Microbiology or Pathology Resident.