Rubella Virus

Rubella is a contagious viral illness, which, prior to vaccination, was responsible for a significant number of fetal losses and congenital abnormalities. The reported number of rubella cases in the U.S. is low enough that the CDC considers it eliminated in 2004.


Indications for Testing

  • Prenatal screening for evidence of immunity (presence of maternal antibodies)
  • Typical symptoms  in unvaccinated patient – rash, fever, headache, pink eye, malaise, lymphadenopathy, cough, rhinitis

Criteria for Diagnosis

  • World Health Organization (WHO) case definition for congenital rubella syndrome (CRS)
    • Suspected case – any infant <1 year in whom a health worker suspects CRS
      • Infant presents with heart disease and/or suspicion of deafness and/or ≥1 of the following eye signs – white pupil (cataract), diminished vision, pendular movement of the eyes (nystagmus), squint, smaller eye ball (microphthalmos), or larger eye ball (congenital glaucoma)
      • Infant’s mother has a history of suspected or confirmed rubella during pregnancy, even when the infant shows no signs of CRS
    • Clinically confirmed case – an infant in whom a qualified physician detects 2 of the complications in section A or 1 from section A and 1 from section B
      • Section A – cataracts, congenital glaucoma, congenital heart disease, hearing impairment, pigmentary retinopathy
      • Section B – purpura, splenomegaly, microcephaly, developmental delay, meningoencephalitis, radiolucent bone disease, jaundice with onset within 24 hours of birth
    • Laboratory-confirmed case – infant with rubella IgM antibody who has clinically confirmed CRS
    • Congenital rubella infection – infant with rubella IgM antibody who does not have clinically confirmed CRS
  • Rubella/German measles case definition (CDC, 2013)

Laboratory Testing

Differential Diagnosis



  • Incidence – <10 cases per year in the U.S. (all contracted outside the country since 2012)
    • CRS – <2/100,000 births
  • Age – usually children who are unvaccinated
  • Transmission
    • Via droplets, aerosol particles – close contact required


  • 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 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
      • 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


  • 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

ARUP Laboratory Tests


Additional Resources

Medical Experts



Marc Roger Couturier, PhD, D(ABMM)
Professor of Pathology (Clinical), University of Utah
Medical Director, Emerging Public Health Crises, Parasitology/Fecal Testing, and Infectious Disease Antigen Testing, ARUP Laboratories