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NC Department of Health and Human Services
State Laboratory of Public Health
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Virology / Serology: Serology


Two HIV serologic assays are utilized as part of an HIV testing algorithm. Initial screening for HIV-1 p24 antigen and antibodies to HIV-1 (including Group O and subtypes) and HIV-2 is performed using an immunoassay (IA). All reactive IAs are repeated in duplicate to verify the initially reactive test result. All repeatedly reactive IA tests (two or more reactive) are tested by the Geenius HIV-1/HIV-2 discriminatory assay that differentiates HIV-1 and HIV-2. Patients who test HIV-1 positive on the Geenius assay should be considered HIV infected. If the test result indicates HIV-2 reactivity, the sample is referred to CDC for HIV-2 confirmation.

Patients who test nonreactive for HIV p24 antigen and HIV-1/HIV-2 antibodies by the IA screening assay can be considered negative for both acute and established HIV infection. Samples that test repeatedly reactive on the screening assay but test as either HIV negative, HIV positive-untypable (undifferentiated), HIV-2 positive with HIV-1 cross-reactivity, HIV indeterminate, HIV-1 indeterminate, HIV-2 indeterminate, or invalid by Geenius are further tested for HIV-1 RNA by nucleic acid amplification (NAAT). Patients with detectable HIV-1 RNA should be considered as likely acute HIV infections.

For specimen submission and shipping guidance, refer to our SCOPE.

Hepatitis C

Hepatitis C is part of a testing algorithm. Initial screening is for anti-HCV antibodies using an immunoassay, with reactives reflexed to NAAT testing. This testing uses the same DHHS 1111 form as HIV and can be tested using the same tube of serum.

For specimen submission and shipping guidance, refer to our SCOPE.

Hepatitis A and B

Hepatitis B serologies are available for diagnosis of acute and chronic disease, for monitoring the course of disease and the effectiveness of therapy, and for screening select patient populations. Hepatitis A IgM testing is available on a limited basis for the diagnosis of acute disease.

Three types of testing panels are available: diagnostic, screening, and monitoring.

For specimen submission and shipping guidance, refer to our SCOPE.


Immune status testing for rubella antibody is available only to local health departments for prenatal patients with no documentation of vaccination or previous immune status testing. Immune status testing for rubella is also available for both clients and health department employees when vaccination is contraindicated (e.g., pregnancy, immunosuppression, or allergy to vaccine components). Reason for contraindication must be noted on the test request.

Please note that all suspect or probable rubella cases must be reported to the Communicable Disease Branch at (919)733-3419 for prior approval of Rubella IgM laboratory testing. Specimens approved for Rubella diagnosis will be forwarded to a reference laboratory for Rubella IgM or PCR testing.

For specimen submission and shipping guidance, refer to our SCOPE.

Virology/Serology Information