Chapter 14: Rubella Figure 1

Manual for the Surveillance of Vaccine-Preventable Diseases

Figure 1

Figure 1. Algorithm for serologic evaluation of pregnant women exposed to rubella

Text version

IgM and IgG at the time of first visit (Save sera)

• IgM+/IgG+
  • Acute infection or false IgM positive
    • Collect 2nd serum 5-10 days later. IgM, IgG and avidity testing to be conducted
      • High avidity, no rise in IgG titers (tested together with first serum) Likely false-positive
      • Low avidity, rise in IgG titers (tested together with first serum) Acute Infection
        • Discuss options for pregnancy outcome
• IgM+/IgG-
  • Acute infection or false IgM positive
    • Collect 2nd serum 5-10 days later. IgM, IgG and avidity testing to be conducted
      • High avidity, no rise in IgG titers (tested together with first serum) Likely false-positive
      • Low avidity, rise in IgG titers (tested together with first serum) Acute Infection
        • Discuss options for pregnancy outcome
• IgM-/IgG-
  • Susceptible
    • Repeat IgM/IgG 3-4 weeks from suspected exposure (Test concurrently with first specimen)
      • Positive IgM+, IgG+
        • Acute Infection
          • Discuss options for pregnancy outcome
      • Negative
        • Repeat IgM/IgG in 6 weeks if risk of exposure continues to exist (Test concurrently with first specimen)
          • Positive IgM+, IgG+
            • Acute Infection
              • Discuss options for pregnancy outcome
          • Negative
            • Infection Discarded
• IgM-/IgG+
  • Immune

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