Rubella Diagnosis

Useful For

Diagnosis of rubella infection in nonimmune individuals.

 

Indications for Testing

Pregnant woman who is exposed to rubella or who develops signs and symptoms of rubella infection.

For those without documented immunization, serological screening is not recommended.

Serological testing before or after immunization is unnecessary and not indicated.

Woman without a prior record of immunization who are tested and found to be non-immune serologically should be vaccinated with one dose of rubella-containing vaccine (MMR) in the immediate post-partum period and before discharge from hospital. They need not be screened for rubella antibodies either after immunization or in subsequent pregnancies, since they are likely protected against congenital rubella syndrome.

 

Method Name

IgM, IgG Enzyme-Linked
Immunosorbent Assay (ELISA)

Reporting Name

Rubella IgM

Rubella IgG

 

Aliases

German Measles

Prenatal

TORCH

Rubella

Specimen Required

Human sera or EDTA/heparinized/citrated plasma

 

Container/Tube: Plain, red-top tube(s) or serum gel tube(s)/ Serum
separator tubes

Specimen Volume: 0.5 mL of serum

Specimen Minimum Volume: 0.5 mL serum

 

Transport Temperature

Specimen Room temperature Refrigerated Frozen
Serum NO YES* YES**

*The samples should be stored for not more than 14 days at 2-8°C.

**For longer delay remove from clot. Red blood cells or separator gel and freeze at < -10°C and transport on dry ice.

 

Reject Due To

Specimens other than Serum (EDTA, Heparin, Citrate) or plasma
Anticoagulants OK
Hemolysis OK, gross REJECT
Lipemia OK
Icteric OK

Useful For

Diagnosis of rubella infection in nonimmune individuals.

 

Clinical Information

Rubella, or German measles, is an acute exanthematous viral infection of children and adults. The clinical illness is characterized by rash, fever, and lymphadenopathy and resembles a mild case of measles. Although many infections with the agent are subclinical, this virus has the potential to cause fetal infection, with resultant birth defects like congenital heart disease and mental retardation, and (uncommonly, but especially in adults) various forms of arthritis.

 

Antibody levels developed in response to earlier generations of rubella vaccines declined over time but this may not have clinical significance since any detectable antibody generally protects against viremic infection, thereby protecting the fetus. Rarely, transient viremia can occur in people who have natural disease or prior immunization, but transmission to the fetus in this circumstance is believed to be rare. Subsequent to the introduction of two-dose MMR vaccine, failure is predicted to be less than for earlier monovalent rubella vaccines. Infection in a previously immune mother (secondary vaccine failure) is rare.

 

Since introduction of the rubella vaccine in 1969 and the measles, mumps, and rubella (MMR) vaccine in 1972, rubella incidence is rare. A total of 9 cases of rubella were reported to the CDC in 2004, and only 4 cases of congenital rubella syndrome were reported between 2001 and 2004. Due to the success of the national vaccination program, rubella is no longer considered endemic in the US. Despite the possibility of worldwide rubella eradication, rubella remains endemic in many countries.

 

Rubella was first described in the 18th century and was accepted as a disease independent of measles and scarlet fever in 1881. A number of small, enveloped viruses having the same overall genetic organization and replication strategy as rubella virus exist, and they are grouped into the Togaviridae family. The Togaviridae family consists of the Rubivirus genus, containing only rubella virus, and the Alphavirus genus, containing about 25 other viruses, all of which are transmitted by arthropods (e.g., western equine encephalitis virus). Rubella virus has a restricted host range and appears to infect only humans.

 

Reference Values

Non-immuneindividuals: NONREACTIVE

Immuneindividuals: REACTIVE

The Rubella IgG test is standardized to the World Health Organization (WHO) 1st International Standard (RUBI-1-94) for anti-rubella immunoglobulin.

 

Interpretation

Rubella IgM Reactive: A reactive result may occur with rubella infection or after vaccination. Possible cross-reactivity with primary EBV, CMV or hepatitis A cannot be excluded.

Non-reactive: A non-reactive result does not exclude early active infection. If clinically indicated submit a follow-up specimen.
Anti-rubella IgM may not be detected in previously vaccinated infected individuals. To confirm active infection virus detection is recommended.

Indeterminate: Specimen produced results near the cut-off (indeterminate), please submit a follow up specimen 1 – 2 weeks to resolve.

 

Rubella IgG

  • ≥ 10 IU/ml is REACTIVE/considered protective for rubella infection.
  • NOTE: Any rubella IgG titer, if previously vaccinated, is sufficient for preventing CRS. There is no need for further evaluation.
  • < 10 IU/ml is NEGATIVE/considered not protective for Rubella

 

Reference

Abbott. 2009. Architect System Rubella IgG: package insert. Abbott Laboratories, Wiesbaden.

 

Bellini, W. J., and Icenogle, J. P. 2007. Measles and Rubella Viruses, p. 1378-1391. In Murray, P. R., Baron, E. J., Jorgensen, J. H., Landry, M. L., and Pfaller, M. A. Manual of Clinical Microbiology, 9th ed., vol. 2. ASM Press, American Society for Microbiology, Washington, DC.

 

Canadian Paediatric Society. Prevention of congenital rubella syndrome. Paediatr Child Health 2007;12(9):795-797.

 

Clinical Practice Obstetrics Committee. Rubella in Pregnancy. J Obstet Gynaecol Can 2008;30(2):152-158.

 

Gershon, A. A. 2010. Rubella Virus (German Measles), p. 2127-2132. In Mandell, D., Bennett, J. E., and Dolin, R. Principles and practice of infectious diseases, 7th ed., vol. 2. Churchill Livingstone, Elsevier, Philadelphia, PA.

 

National Advisory Committee on Immunization. 2006. Canadian Immunization Guide, 7th Ed. Public Health Agency of Canada.

 

Status Days Analytic
Time
Maximum
Laboratory Time
Specimen
Retention
Routine Mon, Wed, Fri 24h 72h 1 month

 

Method Description

Quantitative chemiluminescent microparticle immunoassay (CMIA)

 

Performing Laboratory Location

Newfoundland & Labrador Public Health Laboratory

St. John’s

 

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