Varicella-Zoster Antibody, IgG, Serum
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Varicella-zoster virus (VZV), a herpes virus, causes 2 exanthematous (rash-associated) diseases, chickenpox and herpes zoster (shingles). Chickenpox is a highly contagious disease usually contracted during childhood and is characterized by a dermal vesiculopustular rash that develops in successive crops. Although primary infection results in immunity to subsequently contracting chickenpox, the virus remains latent in the body, localized to the dorsal root or cranial nerve ganglia. Reactivation of latent infection manifests as herpes zoster. On reactivation, the virus migrates along neural pathways to the skin, producing a unilateral rash usually limited to a single dermatome. Reactivation occurs in older adults and in patients with impaired cellular immunity.
Several populations are at risk of suffering unusually severe reactions to VZV infections. The infection in pregnant women may spread through the placenta to the fetus, causing congenital disease in the infant. Immunosuppressed patients in hospitals may contract severe nosocomial infections from others who have active VZV infections. Therefore, serologic screening of direct health care providers (physicians, allied health care personnel) and individuals in high-risk groups is necessary to avoid uncontrolled spread of infection.
Determining the immune status of individuals to varicella-zoster virus
A negative IgG result indicates absence of prior exposure to varicella-zoster virus (VZV) and nonimmunity.
A positive IgG result indicates prior exposure to VZV and immunity.
Equivocal results should be followed up by repeat testing on a new specimen.
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
No significant cautionary statements
Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
Negative (reported as positive or negative)
A negative result indicates nonimmunity.
Clinical References Provides recommendations for further in-depth reading of a clinical nature
1. Gallagher J, Quaid B, Cryan B: Susceptibility to varicella zoster virus infection in health care workers. Occup Med (Oxf) 1996;46:289-292
2. Arvin AM: Varicella-zoster virus. Clin Microbiol Rev 1996;9:361-381