What is the purpose of this test?
Order this Varicella-Zoster Virus (VZV) Antibodies, IgG test to detect and measure antibodies to VZV to confirm previous infection or vaccination. VZV, a member of the herpes virus family, causes chickenpox and shingles. While most people previously infected with chickenpox will develop antibodies, making them immune for the remainder of their lives, the virus remains inactive in the nerve tissue. As a result of a weakened immune system, the virus may reactivate later in life, causing shingles. You can be infected with shingles more than once, though rare, unlike chickenpox.
Chickenpox is a highly contagious disease that causes red, itchy sores (pox) all over the body. It was a prevalent childhood disease, infecting nearly all children in the United States. However, since the development of the chickenpox vaccine in 1995, cases have continued to decline. Chickenpox usually causes mild symptoms in healthy children. In comparison, it can be severe for adults, pregnant women and newborns, and people with weakened immune systems (i.e., those with HIV/AIDS, cancer, and transplant patients).
Shingles is a disease that targets people previously infected with chickenpox. This disease may cause a painful, burning rash on one area of the body or spread to various body parts. Medical experts have estimated that nearly one-third of Americans will get shingles at some point in their lifetime, most often after age 50. The average recovery time for shingles is three to five weeks, but it sometimes causes long-term pain and other health problems.
What is the difference between VZV IgM and IgG antibody tests?
IgM antibody testing is typically the first test used to diagnose VZV infection. Individuals who are newly infected with VZV develop IgM antibodies to the virus. Most individuals will develop IgM antibodies as soon as one to two weeks after exposure. Eventually, the VZV IgM antibody levels decline below detectable levels. However, additional IgM may be produced when latent VZV is reactivated.
IgG antibody testing is another antibody test that may be used to diagnose VZV and establish immunity. The body produces IgG antibodies several weeks after the initial VZV infection, providing long-term protection. IgG levels increase during the active infection, stabilize as the VZV infection resolves, and the virus becomes inactive.
When should I order a Varicella-Zoster Virus (VZV) Antibodies Blood Test, IgG?
Individuals interested in determining their immunity to VZV may order this test. Individuals should also note that this test cannot distinguish between a past or current infection; therefore, a positive result may indicate active infection and not immunity. However, suppose an active infection is not suspected based on the individual’s history, clinical signs, and other laboratory results. In that case, a positive IgG result is likely due to past infection, and the individual is assumed to be immune to the disease. Individuals are advised to follow up with their doctor or healthcare provider if they have significant concerns or questions about their results.
Common signs or symptoms associated with chickenpox and shingles include:
- Itchy, red, blistering pox all over the body (Chickenpox)
- Painful, red, blistering rash on one side of the body (Shingles)
- Fever
- Headaches
- Sore throat
