Laboratory Lab results are too important to go anywhere else.

Rubella IgG

German Measles, Rubella Antibody, IgG

Test Codes

EPIC: LAB6895, Beaker: RUBIG

Department

Special Chemistry

Specimen Collection Criteria

Collect: One Gold-top SST tube. (Minimum Whole Blood: 2.0 mL)

Physician Office/Draw Specimen Preparation

Preparation for Courier Transport

Transport: Centrifuged collection tube, refrigerated (2-8 °C or 36-46 °F). (Minimum Serum: 0.5 mL)

Rejection Criteria

• Plasma specimens.
• Severely lipemic, icteric, or grossly hemolyzed specimens. 

In-Lab Processing

Let specimen clot 30-60 minutes then immediately centrifuge to separate serum from cells. Room temperature is acceptable for a maximum of two hours. (Minimum Serum: 0.5 mL)

Storage

Specimen Stability for Testing:

Centrifuged SST Tubes and Microtainers^® with Separator Gels
Room Temperature (20-26°C or 68-78.8°F): 2 hours
Refrigerated (2-8°C or 36-46°F): 7 days
Frozen (-20°C/-4°F or below): Unacceptable

Red-top Tubes and Microtainers^® without Separator Gels
Room Temperature (20-26°C or 68-78.8°F): 2 hours
Refrigerated (2-8°C or 36-46°F): Unacceptable
Frozen (-20°C/-4°F or below): Unacceptable

Serum Specimens (Pour-Overs)
Room Temperature (20-26°C or 68-78.8°F): 2 hours
Refrigerated (2-8°C or 36-46°F): 7 days
Frozen (-20°C/-4°F or below): 6 months

Specimen Storage in Department Prior to Disposal:

Refrigerated (2-8°C or 36-46°F): 7 days

Laboratory

Royal Oak Special Chemistry Laboratory

Performed

Tuesday – Saturday.
Results available within 2 business days.

Reference Range

Negative:  ≤ 0.8 U
Equivocal:  0.9-1.0 U
Positive:  ≥ 1.1 U

Test Methodology

Multiplex Flow Assay.

Interpretation

• Patients with rubella IgG antibody levels greater than 1.0 IV are considered immune.
• A false negative result may occur if the specimen is drawn very early during the acute stage of infection.
• A negative rubella IgG result does not rule out a recent primary rubella infection.

Clinical Utility

Rubella IgG testing for the determination of rubella immune status. Rubella IgG is first detectable 1-3 days after the onset of symptoms. Antibody levels peak after 1-2 weeks and remain detectable throughout the lifetime of the patient. Demonstration of rubella IgG in a single serum specimen indicates the patient is immune to rubella (1).

Clinical Disease

• Children and adult patients with a rubella infection present with a mild self-limiting disease characterized by rash, fever, and lymphadenopathy. The rash initially appears on the face and rapidly spreads to the trunk, arms, and legs, and disappears in 1-3 days. Adults frequently develop transient polyarthralgia and arthritis after natural infection. Other complications such as thrombocytopenia and encephalopathy rarely occur.
• Rubella infections during pregnancy can frequently cause fetal death, premature delivery, and an array of congenital defects. The effects on the fetus depend upon the time of infection. Generally, the younger the fetus, the more severe the resulting disease. During the first 8 weeks of gestation, the fetus has a 40-60% chance of spontaneous abortion or of acquiring multiple congenital defects. At 12 weeks, the fetus has a 30-35% chance of developing a single defect such as deafness or congenital heart disease. Fetal infection during the 16th week carries a 10% risk of a single congenital defect. Occasionally, fetal damage (deafness) has been observed when rubella infections occur as late as the 20th week of gestation. Infants with congenital rubella may excrete high concentration of virus in nasopharyngeal and other secretions until they are nearly 2 years of age. Contact with these children poses a risk for susceptible pregnant women (1).

Epidemiology

Most rubella cases occur in the spring and early summer (February-May). Prior to 1965, rubella epidemics occurred every 6-9 years and major epidemics occurred at 30-year intervals. The incidence of epidemic rubella has been drastically reduced by immunization programs (1).

Incubation Period

The incubation period is 16-21 days with a mean of 18 days. Patients are infectious for 1 week before and 7-10 days after the rash appears (1).

Transmission

Rubella is mildly contagious. The disease is transmitted through inhalation of virus-laden aerosol droplets (1).

Reference

1. Wiedbrauk D, Johnston SLG. Manual of Clinical Virology, Raven Press, New York, NY, 1993.

CPT Codes

86762
LOINC: 5334-8

Contacts

Last Updated

2/10/2024