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Test ID: HAIGM Hepatitis A IgM Antibody, Serum

Necessary Information

Date of collection is required.

Specimen Required

Collection Container/Tube:

Preferred: Serum gel

Acceptable: Red top

Submission Container/Tube: Plastic vial

Specimen Volume: 1 mL

Collection Instructions:

1. Centrifuge blood collection tube per collection tube manufacturer's instructions (eg, centrifuge and aliquot within 2 hours of collection for BD Vacutainer tubes).

2. Aliquot serum into plastic vial.

Useful For

Diagnosis of acute or recent hepatitis A infection

Special Instructions

Method Name

Chemiluminescent Microparticle Immunoassay (CMIA)

Reporting Name

Hepatitis A IgM Ab, S

Specimen Type


Specimen Minimum Volume

0.4 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Serum Refrigerated (preferred) 7 days
  Ambient  72 hours

Clinical Information

Hepatitis A virus (HAV) is endemic throughout the world, occurring most commonly in areas of poor hygiene and low socioeconomic conditions. The virus is transmitted primarily by the fecal-oral route and spread by close person-to-person contact and by food and waterborne epidemics. Outbreaks frequently occur in overcrowded situations and high-density institutions and centers, such as prisons and healthcare or daycare centers. Viral spread by parenteral routes (eg, exposure to blood) is possible, but rare, because infected individuals are viremic for a short period of time (usually <3 weeks). There is little or no evidence of transplacental transmission from mother to fetus or transmission to newborn during delivery.


Serological diagnosis of acute viral hepatitis A depends on the detection of specific anti-HAV IgM. Its presence in the patient's serum indicates a recent exposure to HAV. HAV-specific IgM antibody level becomes detectable in the blood by 4 weeks after infection, persisting at elevated levels for about 2 months before declining to undetectable levels by 6 months. They rarely persist beyond 12 months after infection.

Reference Values


See Viral Hepatitis Serologic Profiles.


This assay detects the presence of hepatitis A virus (HAV)-specific IgM antibody in serum.


Negative results indicate either inadequate or delayed anti-HAV IgM response after known exposure to HAV or absence of acute or recent hepatitis A.


Equivocal results may be seen in early acute hepatitis A associated with rising anti-HAV IgM levels or recent hepatitis A infection associated with declining anti-HAV IgM levels. Retesting for both anti-HAV IgM (HAIGM / Hepatitis A IgM Antibody, Serum) and anti-HAV IgG (HAIGG / Hepatitis A IgG Antibody, Serum) in 2 to 4 weeks is recommended to determine the definitive HAV infection status.


Positive results indicate acute or recent (<6 months) hepatitis A infection. As required by laws in almost all states, positive anti-HAV IgM test results must be urgently reported to state health departments for epidemiologic investigations of possible outbreak transmission.

Clinical Reference

1. Nelson NP, Weng MK, Hofmeister MG, et al: Prevention of hepatitis A infection in the United States: Recommendations of the Advisory Committee on Immunization Practices, 2020. MMWR Morb Mortal Wkly Rep. 2020 Jul 3;69(5):1-38. Erratum in MMWR Morb Mortal Wkly Rep. 2021 Feb 26;70(8):294

2. de Paula VS: Laboratory diagnosis of hepatitis A. Future Virology. 2012;7(5):461-472

3. Webb GW, Kelly S, Dalton HR: Hepatitis A and hepatitis E: clinical and epidemiological features, diagnosis, treatment, and prevention. Clin Microbiol Newsl. 2020 Nov 1;42(21):171-179

Day(s) Performed

Monday through Saturday

Report Available

1 to 2 days

Test Classification

This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.

CPT Code Information


LOINC Code Information

Test ID Test Order Name Order LOINC Value
HAIGM Hepatitis A IgM Ab, S 13950-1


Result ID Test Result Name Result LOINC Value
HAIGM Hepatitis A IgM Ab, S 13950-1


If not ordering electronically, complete, print, and send 1 of the following:

-Gastroenterology and Hepatology Client Test Request (T728)

-Infectious Disease Serology Test Request (T916)

Mayo Clinic Laboratories | Microbiology and Infectious Disease Catalog Additional Information: