It is a herpes family virus, which is known to cause 2 diseases namely chickenpox (varicella) & shingles (herpes zoster). Chicken pox is known as a highly contagious disease, though it is typically benign & contracted during childhood. It is passed from person to person via coughing, sneezing or touching fluid from blisters. It is characterized by an itchy rash followed by pimple-like papule formation that turn into small, fluid-filled blisters (vesicles). The vesicles break forms a crust & then heal.
What is VZV (chicken pox) IgM Abs Lab Test?
This lab test is used to determine a person’s immune system against varicella zoster virus. Initially when the body is infected with VZV, body’s immune system defends by producing two types of antibodies i.e. first IgM appears 1 to 2 weeks after contracting the infection & stays for a few weeks before disappearing. Next IgG antibodies appear which lasts for the rest of the person’s life.
This test detects IgM antibodies specific for VZV, if present, they help confirm the diagnosis of acute or recent VZV infection. IgM response to VZV can be detected at 7 days post-infection, and its results should be correlated with clinical presentation.
Why is VZV (chicken pox) IgM Abs Lab Test done?
Most of the time, testing is considered not necessary for diagnosis of active chicken pox infection, as it can be made from the clinical signs & symptoms. However, it becomes necessary in people with atypical skin lesions, to confirm chickenpox infection. This lab test is done:
To diagnose a current infection in organ transplant recipients & pregnant females
In HIV/AIDS patient
Distinguish between active or prior infection
Determines if someone with severe or atypical symptoms has got an active VZV infection or has another condition with similar symptoms
What does the test measure?
This test looks for antibodies in the blood that the body makes against the varicella-zoster virus.
The varicella-zoster virus is very contagious. It can cause two health problems:
When the body becomes infected with the virus for the first time, it causes 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 the body. Later in life, the virus can become active again. It causes a painful rash called shingles, or herpes zoster.
Q1. How is the test performed?
A blood sample is obtained from the vein.
Q2. Is there any risk associated with the test?
There is no significant risk associated with this test, however, in rare cases, a patient may develop a clot or hematoma around the site of the needle prick. Other complications include nausea, vomiting, and diarrhea.
Q3. What might affect the test results?
A history of chickenpox or vaccine against the disease can affect the results.
When someone is exposed to the Varciella-zoster virus, the person's immune system responds by producing antibodies to the virus. Laboratory tests can detect and measure the level of VZV lgM antibodies in the blood.
lgM antibodies are the first to be produced by the body in response to a VZV infection. They are present in most individuals within a week or two after the initial exposure. lgM antibody production rises for a short period and declines. Eventually, the level lgM antibody usually falls below detectable levels.