Rubella Virus

  • Diagnosis
  • Background
  • Lab Tests
  • References
  • Related Topics

Indications for Testing

  • Prenatal screening for presence of maternal antibodies
  • Typical rash in unvaccinated patient

Criteria for Diagnosis

  • Rubella/German measles case definition (CDC, 2013)

Laboratory Testing

  • CDC – testing recommendations
  • Rubella laboratory testing (CDC, 2016)
  • Serology
    • In primary rubella infection, the appearance of clinical symptoms is associated with the appearance of both IgG and IgM antibodies
      • IgM antibodies – detectable a few days after onset of symptoms; peak 7-10 days later
      • May consider fetal IgM serology if fetal infection suspected indicating previous infection and immunity
    • Prenatal screening – test women prior to pregnancy to confirm presence of IgG antibodies indicating previous infection and immunity
    • Serologic testing for rubella and CRS in low prevalence setting
  • PCR
    • Usually throat or urine samples
    • Amniotic fluid when fetus is at least 2 weeks of age to identify fetal infection
  • Congenital – see CDC testing recommendations above

Differential Diagnosis

The reported number of rubella cases in the U.S. over the last 5 years is low enough for the Centers for Disease Control (CDC) to state that the endemic disease has been eliminated.

Epidemiology

  • Incidence – <25 cases a year in the U.S.
    • Congenital rubella syndrome – <2/100,000 births
  • Age – usually young children who are unvaccinated
  • Transmission
    • Via droplets, aerosol particles – close contact required

Organism

  • Rubella, an RNA virus, is a member of the Togaviridae family
  • Virus infects cells in the upper respiratory tract and replicates in the lymphoid system; virus then spreads to other organs

Clinical Presentation

  • Transmission can occur up to 7 days before and 7 days after onset of the rash
  • In children and adults, infection usually results in mild, exanthematous disease
    • Adults are more likely to experience prodromal phase – fever, headache, sore throat, cough, conjunctivitis
    • Rare complications – arthralgias and arthritis, thrombocytopenia, hemorrhage, and encephalitis
  • In pregnant women, particularly during first trimester, infection can result in fetal death or congenital abnormalities
    • Disease can be asymptomatic
    • Congenital abnormalities include the following
      • Ophthalmologic – cataracts, glaucoma, iris hypoplasia, retinopathy
      • Otorhinolaryngologic – sensorineural or central deafness
      • Cardiac – patent ductus arteriosus, pulmonary stenosis, pulmonary arterial hypoplasias, myocarditis
      • Central nervous system – developmental delay with central nervous system calcifications, microcephaly
      • Dermatologic – petechia, purpura
    • 10-20% of newborns infected in utero will die during the first year of life
    • Because complications in utero are so severe, diagnosis during first trimester may result in decision to terminate pregnancy
    • Delayed manifestations

Prevention

  • Vaccination programs have resulted in marked decrease in infections
    • Estimated >95% of children in U.S. are vaccinated (recommended between ages 12-15 months)
    • Vaccine is live, attenuated virus and contraindicated in pregnant women
Tests generally appear in the order most useful for common clinical situations. Click on number for test-specific information in the ARUP Laboratory Test Directory.

Rubella Antibodies, IgG and IgM 0050552
Method: Semi-Quantitative Chemiluminescent Immunoassay

Follow-up 

If test results are equivocal, repeat testing in 10-14 days 

Rubella Antibody, IgG 0050771
Method: Semi-quantitative Chemiluminescent Immunoassay

Guidelines

Adult Immunization Schedule. Center for Disease Control and Prevention. [Last updated Oct 2016; Accessed: Jan 2017]

Centers for Disease Control and Prevention (CDC). Recommendations from an ad hoc Meeting of the WHO Measles and Rubella Laboratory Network (LabNet) on use of alternative diagnostic samples for measles and rubella surveillance. MMWR Morb Mortal Wkly Rep. 2008; 57(24): 657-60. PubMed

Manual for the Surveillance of Vaccine-Preventable Diseases . Centers for Disease Control and Prevention. Atlanta, GA [Last updated Apr 2014; Accessed: Feb 2017]

U.S. Department of Health and Human Services, Centers for Disease Control and Prevention. Recommended Immunization Schedules for Persons Aged 0 Through 18 Years. United States, 2016. Centers for Disease Control and Prevention. Atlanta, GA [Last Updated Jan 2016; Accessed: Dec 2016]

General References

Neu N, Duchon J, Zachariah P. TORCH infections. Clin Perinatol. 2015 Mar;42(1):77-103, viii. PubMed

References from the ARUP Institute for Clinical and Experimental Pathology®

Owen WE, Martins TB, Litwin CM, Roberts WL. Performance characteristics of six IMMULITE 2000 TORCH assays. Am J Clin Pathol. 2006; 126(6): 900-5. PubMed

Shirts BH, Welch RJ, Couturier MR. Seropositivity rates for measles, mumps, and rubella IgG and costs associated with testing and revaccination. Clin Vaccine Immunol. 2013; 20(3): 443-5. PubMed

Medical Reviewers

Last Update: February 2017