HERPES SIMPLEX VIRUS I (HSV)-IgM Detail

The HSV IgM test is a blood test used to detect Immunoglobulin M (IgM) antibodies produced in response to a recent or primary infection with the Herpes Simplex Virus (HSV), which includes HSV-1 and HSV-2.

• HSV-1 typically causes oral herpes (cold sores),

• HSV-2 usually causes genital herpes.

A positive HSV IgM result suggests recent exposure or reactivation of a latent infection. However, IgM tests may sometimes give false positives due to cross-reactivity, and they cannot reliably differentiate between HSV-1 and HSV-2 infections.

The HSV IgM test is commonly used:

• To support the diagnosis of early-stage HSV infections

• In patients presenting with new onset of herpetic sores or blisters

• In certain prenatal screenings to assess infection risks to the fetus

Due to limitations of the IgM test, confirmation with HSV IgG testing, viral culture, or HSV PCR testing may be recommended for accurate diagnosis and typing.