Serum

Red top tube

3 mL; red top tube

Hemolyzed, icteric or Lipemic specimens, plasma specimens.

Test performed on Monday, Wednesday and Friday.

3 days

See Interpretive Data

Negative - No significant level of detectable varicella-zoster IgG antibody
Equivocal - Repeat testing in 7-14 days may be helpful
Positive - IgG antibody to varicella-zoster detected, which may indicate a current or past varicella-zoster infection. Positive IgG antibody levels in the absence of current clinical symptoms may indicate immunity.

The results of the test are qualitative and should be considered as either positive or negative for the presence of antibodies against varicella-zoster virus. Patients with a current primary infection of varicella may not begin producing measurable concentrations of anti- varicella antibodies until several days after infection. The best evidence for current infection is a significant change of two appropriately timed specimens, where both tests are done in the same laboratory at the same time. The presence of anti-varicella IgG antibodies indicates prior exposure to the virus but does not exclude the possibility of an ongoing infection. Quantitative testing on acute and convalescent phase paired sera or an assay for the presence of IgM varicella antibodies may be helpful in diagnosing recent infection.

A positive test result in immunocompromised patients receiving prophylactic treatment with zoster immune serum globulin or zoster immune plasma may not be indicative of prior infection with VZV. Interference may be encountered with certain sera containing antibodies directed against reagent components. For this reason, assay results should be interpreted taking into consideration the patient's history, and the results of any other tests performed.

Enzyme Linked Fluorescent Immunoassay (ELFA)

86787