Helicobacter pylori – Antibody

Consistent with O. Reg. 671/92 of the French Language Services Act, laboratory testing information on this page is only available in English because it is scientific or technical in nature and is for use only by qualified health care providers and not by members of the public.

Background
This page provides antibody (serology) testing information for Helicobacter pylori at Public Health Ontario (PHO).

Alternative noninvasive H. pylori testing methods such as urea breath test, stool antigen, or stool PCR are not available at PHO, but may be available at other community or hospital laboratories. Invasive biopsy testing methods such as histology, rapid urease, or direct culture are also not available at PHO.

Updates

Effective July 22, 2026, PHO will update the routine acceptance criteria for all H. pylori serology requests as per the Testing Indications below.

*Uncontrolled print copy. Valid only on day of print: 23 June 2026.

Testing Indications

Testing for H. pylori should only be considered if there is planned follow-up for treatment. The main established testing and treatment indications for H. pylori are^1-9:

Peptic ulcer disease
Gastric cancer risk (e.g., MALT, premalignancy, dysplasia, gastritis, first degree family history)
Unexplained dyspepsia in adults* (i.e. epigastric pain lasting at least 1 month in the absence of predominant reflux-like symptoms)

Other indications with limited or conflicting evidence include:

Refractory iron deficiency anemia after appropriate evaluation and iron supplementation
Long-term nonsteroidal anti-inflammatory drug (NSAID) use in adults*
Idiopathic (autoimmune) thrombocytopenic purpura in adults*
Bariatric surgery pre-operative screening in adults*
Household member diagnosed with H. pylori by non-serological testing in adults*

The indications with an asterisk (*) are not currently supported in pediatric populations.

As per Choosing Wisely, serology is no longer a recommended primary testing method for diagnosis of active H. pylori infection. Instead, alternative non-invasive methods such as stool antigen or urea breath tests should be preferentially used in adults with no alarming signs. Although these alternative methods are not available at PHO, such tests may be offered at other community laboratories (e.g. private or hospital laboratories). Individuals with alarming signs, as well as some pediatric populations, may warrant endoscopic evaluation as opposed to non-invasive testing.^3,10

Acceptance/Rejection Criteria

H. pylori serum samples will be rejected at PHO if:

Received without clinical information compatible with the testing indications stated above
Stored refrigerated (e.g. 2-8°C) for more than 48 hours from time of collection (H. pylori serum samples should be frozen if delays of greater than 48 hours are expected)
Received without date of collection specified on the requisition

Specimen Collection and Handling

Specimen Requirements

Test Requested	Required Requisition(s)	Specimen Type	Minimum Volume	Collection Kit
H. pylori IgG and/or antibody and/or serology	General Test Requisition	Serum	5 mL of clotted whole blood or 0.5 mL serum	Blood, clotted – serum separator tube (SST)

Submission and Collection Notes

Complete all fields of the General Test Requisition form.

Include required clinical information (e.g. ulcer, cancer, dyspepsia, anemia, NSAID, purpura, bariatric, or household exposure).

Label the specimen container(s) with the patient’s first and last name, date of collection, and one other unique identifier such as the patient’s date of birth or Health Card Number. Failure to provide the information indicated above will be cancelled. Cancelled submissions will require a new sample submission with an appropriate indication if testing is clinically indicated.

Limitations

Grossly haemolysed, lipemic, contaminated specimens and specimens containing anticoagulant are unsuitable for testing.

Storage and Transport

Centrifuge if using SST. To prevent erroneous results due to the presence of fibrin, ensure that complete clot formation has taken place prior to centrifugation of samples.
Specimens should be stored at 2-8°C and shipped within 48 hours of collection on ice packs.
If delays of more than 48 hours are anticipated, serum specimens may be stored frozen (-20°C) and shipped on dry ice.
All clinical specimens must be shipped in accordance with the Transportation of Dangerous Goods Act.

Requisitions and Kit Ordering

Test Frequency and Turnaround Time (TAT)

H. pylori serology is performed Monday to Friday at PHO’s laboratory. Turnaround time is up to 7 days from receipt at PHO’s laboratory..

Test Methods

Method: Helicobacter pylori serology is performed using the Diasorin LIAISON H. pylori IgG assay. The assay is an indirect chemiluminescence immunoassay (CLIA) that provides qualitative detection of IgG antibodies to H. pylori antigens in serum.

Performance: Approximate sensitivity of H. pylori serology has traditionally been estimated between 85% and 95%, and specificity has been estimated between 70% and 90%.^11-13

Limitations: Due to the lower test specificity, false positives may occur in low prevalence settings. Seropositivity alone does not distinguish active from resolved infection. Clinical assessment and additional testing with a stool antigen or urea breath test should be considered if clinically indicated. Serological follow-up testing of individuals after primary diagnosis is not advised, since serology may remain positive for years despite successful eradication.

Interpretation

The following table provides possible test results with associated interpretations:

H. pylori IgG CLIA Result	Interpretation
Positive	A positive result indicates the presence of detectable IgG antibody to H. pylori. False positives may occur therefore clinical correlation is required. A positive result does not distinguish active from resolved infection.
Equivocal	Results are inconclusive. Repeat testing may be indicated if there is ongoing clinical suspicion of H. pylori infection.
Negative	A negative result generally indicates that the patient has not been infected, but does not always rule out recent H. pylori infection.

Reporting

Results are reported to the physician, authorized health care provider (General O. Reg 45/22, s.18) or submitter as indicated on the requisition.

References

Chey WD, Howden CW, Moss SF, Morgan DR, Greer KB, Grover S, Shah SC. ACG Clinical Guideline: Treatment of Helicobacter pylori Infection. Am J Gastroenterol. 2024 Sep 1;119(9):1730-1753. doi: 10.14309/ajg.0000000000002968. Epub 2024 Sep 4. PMID: 39626064.
Moayyedi P, Lacy BE, Andrews CN, Enns RA, Howden CW, Vakil N. ACG and CAG Clinical Guideline: Management of Dyspepsia. Am J Gastroenterol. 2017 Jul;112(7):988-1013. doi: 10.1038/ajg.2017.154. Epub 2017 Jun 20. Erratum in: Am J Gastroenterol. 2017 Sep;112(9):1484. doi: 10.1038/ajg.2017.238. PMID: 28631728.
Homan M, Jones NL, Bontems P, Carroll MW, Czinn SJ, Gold BD, Goodman K, Harris PR, Jerris R, Kalach N, Kori M, Megraud F, Rowland M, Tavares M; on behalf of ESPGHAN/NASPGHAN. Updated joint ESPGHAN/NASPGHAN guidelines for management of Helicobacter pylori infection in children and adolescents (2023). J Pediatr Gastroenterol Nutr. 2024 Sep;79(3):758-785. doi: 10.1002/jpn3.12314. Epub 2024 Aug 15. PMID: 39148213.
Katelaris P, Hunt R, Bazzoli F, Cohen H, Fock KM, Gemilyan M, Malfertheiner P, Megraud F, Piscoya A, Quach D, Vakil N, Vaz Coelho LG, LeMair A. World Gastroenterology Organisation Global Guidelines on Helicobacter pylori. 2021 May. Available online at: https://www.worldgastroenterology.org/guidelines/helicobacter-pylori
Malfertheiner P, Megraud F, Rokkas T, Gisbert JP, Liou JM, Schulz C, Gasbarrini A, Hunt RH, Leja M, O'Morain C, Rugge M, Suerbaum S, Tilg H, Sugano K, El-Omar EM; European Helicobacter and Microbiota Study group. Management of Helicobacter pylori infection: the Maastricht VI/Florence consensus report. Gut. 2022 Aug 8:gutjnl-2022-327745. doi: 10.1136/gutjnl-2022-327745. Epub ahead of print. PMID: 35944925.
El-Serag HB, Kao JY, Kanwal F, Gilger M, LoVecchio F, Moss SF, Crowe SE, Elfant A, Haas T, Hapke RJ, Graham DY. Houston Consensus Conference on Testing for Helicobacter pylori Infection in the United States. Clin Gastroenterol Hepatol. 2018 Jul;16(7):992-1002.e6. doi: 10.1016/j.cgh.2018.03.013. Epub 2018 Mar 17. Erratum in: Clin Gastroenterol Hepatol. 2019 Mar;17(4):801. doi: 10.1016/j.cgh.2019.01.006.. Crowe, Sheila [corrected to Crowe, Sheila E]. PMID: 29559361; PMCID: PMC6913173.
Liou JM, Malfertheiner P, Hong TC, Cheng HC, Sugano K, Shah S, Sheu BS, Chen MJ, Chiang TH, Chen YC, Yamaoka Y, Wong SH, Chen CC, Lee YY, Quach DT, Wu DC, Hsu PI, Wu CY, Wu JY, Luo JC, Chang WL, Lu H, Suzuki H, Jung HY, Mahachai V, Vilaichone RK, Mégraud F, Lin JT, Yeoh KG, Leung WK, El-Omar EM, Lee YC, Wu MS; Asian Pacific Alliance on Helicobacter and Microbiota (APAHAM). Screening and eradication of Helicobacter pylori for gastric cancer prevention: Taipei Global Consensus II. Gut. 2025 Oct 8;74(11):1767-1791. doi: 10.1136/gutjnl-2025-336027. PMID: 40912906.
International Agency for Research on Cancer (IARC).
Population-Based Helicobacter pylori Screen-and-Treat Strategies for Gastric Cancer Prevention: Guidance on Implementation. World Health Organization. 2025. Available online at: IARC Publications Website - Population-Based Helicobacter pylori Screen-and-Treat Strategies for Gastric Cancer Prevention: Guidance on Implementation
Vosburg RW, Nimeri A, Azagury D, Grover B, Noria S, Papasavas P, Carter J. American Society for Metabolic and Bariatric Surgery literature review on risk factors, screening recommendations, and prophylaxis for marginal ulcers after metabolic and bariatric surgery. Surg Obes Relat Dis. 2025 Feb;21(2):101-108. doi: 10.1016/j.soard.2024.10.013. Epub 2024 Oct 15. PMID: 39521634.
American Academy of Family Physicians. Don’t request serology for Helicobacter pylori. American Family Physician Choosing Wisely Collection, 318. Available online at: https://www.aafp.org/pubs/afp/collections/choosing-wisely/318.html
Xie F, O'Reilly D, Ferrusi IL, Blackhouse G, Bowen JM, Tarride JE, Goeree R. Illustrating economic evaluation of diagnostic technologies: comparing Helicobacter pylori screening strategies in prevention of gastric cancer in Canada. J Am Coll Radiol. 2009 May;6(5):317-23. doi: 10.1016/j.jacr.2009.01.022.
Elwyn G, Taubert M, Davies S, Brown G, Allison M, Phillips C. Which test is best for Helicobacter pylori? A cost-effectiveness model using decision analysis. Br J Gen Pract. 2007 May;57(538):401-3.
Pak K, Junga Z, Mertz A, Singla M. The Patterns and Associated Cost of Serologic Testing for Helicobacter pylori in the U.S. Military Health System. Mil Med. 2020 Sep 18;185(9-10):e1417-e1419. doi: 10.1093/milmed/usaa141.