Not immune | Early Acute phase | Acute phase or primary infection | Chronic phase or reinfection | ||
---|---|---|---|---|---|
Description | No symptoms | Typical rash and flu-like symptoms or asymptomatic | Asymptomatic | ||
Rubella IgM | - | + | + | + | - |
Rubella IgG | - | - | + | + | + |
Rubella IgG Avidity and/or Immunoblot* | n.a. | Low | Low | High | n.a./High |
* performed only in specialized labs.
n.a. not applicable
Adapted from:
a) for use on the cobas® e 411 analyzer and the cobas® e 601 / 602 modules
b) for use on the cobas® e 402 and cobas® e 801 analytical units
Rubella IgM | Rubella IgG | Interpretation |
---|---|---|
- | - | Susceptible / No current or previous rubella infection; repeat IgM and IgG testing 2 – 3 weeks later; before pregnancy or post-partum vaccination is recommended. |
- | + | Immune; no further testing required. The presence of antibodies at any level is sufficient to confirm immunity6. |
+ | - | Acute or recent rubella infection or false positive/unspecific IgM. Best period for testing is in a serum collected within the first few days after rash onset. Test for other causes, e.g. rheumatoid factor, EBV, CMV, Parvovirus B19. Test a second sample 5 – 10 days later, if available, and perform IgG avidity. A significant rise of the rubella IgG titer from a first to a second sample supports the diagnosis of acute rubella infection. |
+ | + |
* except infants
Adapted from:
Immunity to rubella.
No further testing required.
Acute infection
Symptomatic treatment
Assessment of fetal infection with PCR in chorionic villous and amniotic fluid samples.
Discuss options for pregnancy outcome.
Acute or recent infection excluded.
Likely false IgM positive or persistent IgM.
Acute infection
Symptomatic treatment.
Assessment of fetal infection with PCR in chorionic villous and amniotic fluid samples.
Discuss options for pregnancy outcome.
Acute infection suspected due to IgG seroconversion or reinfection in case of history of vaccination.
Repeat testing and perform IgG avidity test. High IgG avidity confirms a reinfection, while low IgG avidity indicates a primary infection.
Make sure follow-up testing is always done with assays from the same manufacturer.
Symptomatic treatment.
Assessment of fetal infection with PCR in chorionic villous and amniotic fluid samples.
Discuss options for pregnancy outcome.
Acute infection suspected or false positive IgM.
Acute infection is highly suspected if IgM reactivity is confirmed.
If IgM reactivity is not confirmed, the result is considered to be false positive.
No acute infection, susceptible to infection.
Advice, monitoring, and vaccination before pregnancy or after delivery.
Acute infection.
Symptomatic treatment.
Assessment of fetal infection with PCR in chorionic villous and amniotic fluid samples.
Discuss options for pregnancy outcome.
Acute infection suspected or false positive IgM.
Repeat IgM testing and confirm with immunoblot if possible.
Acute infection suspected due to IgG seroconversion or reinfection in case of history of vaccination.
Make sure follow-up testing is always done with assays from the same manufacturer.
Acute or recent rubella infection or false positive/unspecific IgM.
Test a second sample 5 – 10 days later, if available, and perform IgG avidity in case of positive IgG.
Acute or recent infection is excluded. Likely a persistent or false positive IgM.
Susceptible to infection.
Repeat IgM and IgG tests in parallel.
Acute infection suspected due to IgG seroconversion or reinfection in case of history of vaccination.
Make sure follow-up testing is always done with assays from the same manufacturer.
Acute infection suspected or false positive IgM.
Repeat IgM testing and confirm with immunoblot if possible.
No acute infection, susceptible to infection.
Vaccination is recommended.
Acute infection suspected .
Acute infection suspected or false positive IgM.