What test is used to confirm rubella infection?

What test is used to confirm rubella infection?

• A. Complete blood count
• B. Rubella-specific IgM antibodies by enzyme immunoassay
• C. PCR of nasopharyngeal swab
• D. Chest X-ray

Answer: (B)

Detecting a recent rubella infection hinges on identifying the body’s acute immune response to the virus. The most informative confirmatory test is rubella-specific IgM antibodies measured by an enzyme immunoassay (ELISA). IgM appears soon after infection and indicates a recent or active infection, whereas IgG reflects past immunity and does not confirm current illness. If IgM results are inconclusive or there’s ongoing suspicion, repeat testing or an IgG avidity study can help distinguish recent from past infection. While PCR can detect rubella RNA in early disease, serology for IgM is the standard confirmatory test in most clinical settings.

Detecting a recent rubella infection hinges on identifying the body’s acute immune response to the virus. The most informative confirmatory test is rubella-specific IgM antibodies measured by an enzyme immunoassay (ELISA). IgM appears soon after infection and indicates a recent or active infection, whereas IgG reflects past immunity and does not confirm current illness. If IgM results are inconclusive or there’s ongoing suspicion, repeat testing or an IgG avidity study can help distinguish recent from past infection. While PCR can detect rubella RNA in early disease, serology for IgM is the standard confirmatory test in most clinical settings.