MICHIGAN DEPARTMENT OF HEALTH & HUMAN SERVICES

BUREAU OF LABORATORIES

Rubella IgM Antibody Determination

Rev. 8/20/2018

Rubella IgM Antibody Determination

ANALYTES TESTED: Rubella IgMantibody. PRIOR APPROVAL REQUIRED, see note 1 below.

USE OF TEST: Determination of the presence of Rubella IgM antibody by Capture Enzyme Immunoassay (EIA).

SPECIMEN COLLECTION AND SUBMISSION GUIDELINES:

Test Request Form DCH-0583

Specimen Submission Guidelines

Serum Specimen Collection DCH-0811

Transport Temperature: Frozen, wet ice or ambient temperature.

SPECIMEN TYPE:

Specimen Required: Serum

Minimum Acceptable Volume:1 ml

Container: 3 or 5 ml plastic tube with skirted cap.

Shipping Unit: Unit 8

SPECIMEN REJECTION CRITERIA:

Specimens lacking two unique patient identifiers (i.e., full name, date of birth) will not be tested.

Plasma is unacceptable for testing by this method.

TEST PERFORMED:

Methodology: IgM Capture Enzyme Immunoassay (EIA).

Turn Around Time:1 – 2 weeks (results usually available within 1 week).

Where/When Performed:Lansing, weekly.

RESULT INTERPRETATION:

Reference Range: ABSENT (No antibody detected).

  1. Antibody Present:

The presence of Rubella IgM antibody in a single serum specimen suggests a recent exposure, most likely within the preceding month.

Antibody Absent:

The absence of Rubella IgM antibody does not exclude the possibility of active infection. Timing of sample collection must be considered.

  1. Equivocal Result:

Equivocal Rubella IgM results have been observed in patients who are in the process of seroconversion. Collection of a convalescent serum specimen drawn 10-14 days later for repeat IgM testing is recommended.

FEES:N/A

NOTES:

  1. Rubella IgM testing is only performed upon prior approval by the Bureau of Epidemiology 517-335-8165or the Virology Section Manager 517-335-8099.
  1. False positive IgM results are possible. When uncertain, paired IgG serum analysis and/or PCR testing should be performed. The demonstration of a four-fold increase in IgG antibody between the acute and convalescent sera confirms the diagnosis. The acute specimen should be obtained as soon as possible after onset of symptoms and the convalescent specimen should be obtained 10-14 days later.
  1. IgM antibodies are usually detectable within a few days after onset of symptoms (i.e., fever, rash). However, in specimens collected less than 5 days after rash onset false negative IgM results may occur. Repeat testing on serum collected 10-14 days later is recommended.
  1. IgM antibody wanes rapidly after recovery and is usually undetectable after one month. However, IgM antibodies to rubella virus may occasionally persist at low levels for up to one year after acute infection and post vaccination.
  1. In newborns the presence of IgM antibody is diagnostically significant for congenital infection.

ALIASES: Rubella IgM, German Measles

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