The HSV-1 & HSV-2 IgM test is a serological assay used to detect IgM antibodies specific to Herpes Simplex Virus types 1 and 2 in the blood. IgM antibodies are typically the first antibodies produced by the immune system in response to a new or recent infection. Detection of HSV IgM indicates a recent or primary herpes infection rather than a past infection.

• HSV-1 primarily causes oral herpes (cold sores), but can also cause genital infections. 
• HSV-2 primarily causes genital herpes but can occasionally cause oral infections.