Varicella Zoster IgM Antibodies Blood Test

Varicella zoster virus (VZV) IgM antibodies are produced early in the immune response to VZV infection. They typically appear within the first week of symptom onset and may remain detectable for several weeks to months. Their presence indicates current or recent VZV infection. What Positive Means: A positive VZV IgM result indicates current or recent infection with varicella zoster virus. This may represent primary infection (chickenpox) or viral reactivation (shingles). In pregnant women, a positive result requires urgent medical assessment as VZV can cause fetal abnormalities, particularly in early pregnancy, and neonatal varicella if infection occurs around the time of delivery. What Negative Means: A negative VZV IgM result suggests no current or recent VZV infection. However, if tested very early after exposure or symptom onset, antibodies may not yet have developed. A negative result does not indicate immunity—for immunity assessment, an IgG test is required. Chickenpox (Varicella): Primary VZV infection causes chickenpox, characterised by an itchy, blistering rash that progresses through stages (macules, papules, vesicles, crusts), fever, and general malaise. It is highly contagious and spreads through respiratory droplets and direct contact with lesions. Shingles (Herpes Zoster): After primary infection, VZV remains dormant in nerve ganglia and can reactivate later in life to cause shingles. This presents as a painful, blistering rash typically affecting a single dermatome (band of skin supplied by one nerve). Shingles can occur at any age but is more common in older adults and immunocompromised individuals.