Serum varicella immunoglobulin G antibody level
This test looks for antibodies in your blood that your body makes against the varicella-zoster virus.
The varicella-zoster virus is very contagious. It can cause two health problems: chickenpox and shingles. When you become infected with the virus for the first time, it causes chickenpox. After having chickenpox, most people become immune to the virus for the rest of their life. They can't get chickenpox again.
But after the first illness, the virus becomes dormant and "hides" in nerves in your body. Later in your life, the virus can become active again. It causes a painful rash called shingles, or herpes zoster.
You might have this test if your healthcare provider needs to find out whether you are likely to get a varicella infection. This information can help healthcare workers who may work with patients who have the virus.
This test can also help your provider find out whether you have chickenpox if the diagnosis isn't clear. Symptoms of chickenpox include:
Distinctive rash around the body a day or two after other symptoms begin
The rash lasts for about 2 weeks. It can spread until all the spots on the skin have crusted over.
You aren't likely to need any other tests.
Many things may affect your lab test results. These include the method each lab uses to do the test. Even if your test results are different from the normal value, you may not have a problem. To learn what the results mean for you, talk with your healthcare provider.
If testing is done to see if you are at risk of developing an infection and it finds varicella-related immunoglobulin G (IgG) antibodies in your blood, it means you are immune. You have had a chickenpox infection or having been immunized successfully.
If your healthcare provider suspects that you have chickenpox, your IgG levels can mean you have an infection if they rise over several weeks. In these cases, this test is usually needed only if your provider is unsure about the diagnosis after examining you.
The test requires a blood sample, which is drawn through a needle from a vein in your arm.
Taking a blood sample with a needle carries risks that include bleeding, infection, bruising, or feeling dizzy. When the needle pricks your arm, you may feel a slight stinging sensation or pain. Afterward, the site may be slightly sore.
Having a history of chickenpox or vaccination against the disease can affect your results.
You don't need to prepare for this test. But be sure your healthcare provider knows about all medicines, herbs, vitamins, and supplements you are taking. This includes medicines that don't need a prescription and any illicit drugs you may use.