Antibody to *Escherichia coli* O157:H7 (IgG) in serum/plasma
This test measures the level of antibodies your immune system produces in response to *Escherichia coli* O157:H7, a type of harmful bacteria often linked to foodborne illness.
["It helps identify past exposure to this bacteria, which can cause severe infections like hemolytic uremic syndrome (HUS)."]
Key facts at a glance
- LOINC
- 63402-2
- Short code
- ENA SS-A Ab CSF Ql IA
- Synonyms
- ENA SS-A Ab CSF Ql IA
- Category
- chemistry
- Sample
- csf
- Container
- Sterile tube
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- ia
- Specimen volume
- 1-2 mL
- Stability
- Immediate analysis required, Refrigerated: 1h
- Hemolysis max
- 200
- TAT
- 4–24 hours
- Order
- routine
Why This Test Might Be Ordered
Your healthcare provider may recommend this test if you’ve had symptoms like severe diarrhea, vomiting, or blood in your stool that could suggest an infection from *E. coli* O157:H7. They might also order it for people who’ve been exposed to contaminated food or water or have risk factors like traveling to areas with poor sanitation.
What to Expect Before the Test
No special preparation is usually needed. You may provide a blood sample during a routine office visit or at a lab. If you’re tested for urine or other specimens, follow any instructions given by your provider.
What the Test Results Mean
Positive results indicate your body has produced antibodies against *E. coli* O157:H7, suggesting past infection. Negative results mean no detectable antibodies were found. Results alone don’t confirm current infection; they show exposure history.
Possible Side Effects or Risks
Blood tests are generally safe with minimal risks. You might experience mild bruising or soreness at the needle site, but these are uncommon. Rarely, allergic reactions can occur, though they’re very uncommon with standard procedures.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
E. coli O157:H7 Antibody Test (IgG)
Frequently asked questions
This test is primarily used to diagnose or confirm past infections by *E. coli* O157:H7, which can cause serious illnesses. It’s not typically used for active infection detection, as other tests (like stool cultures) are preferred for that purpose. Antibody testing helps track exposure in outbreaks or for research purposes.
Results are usually available within 24 to 72 hours, depending on your lab’s processing times. Your healthcare provider will contact you once they have the results.
For blood tests, you can eat and drink normally unless your provider specifies otherwise. No fasting is required for this antibody test.
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy