HSV-1 IgM 1. This assay is used for qualitative detection of specific IgM antibodies to Herpes Simplex virus 1 in serum samples. 2. Positive result for Herpes Simplex virus 1 IgM may indicate acute infection, reinfection or reactivation of latent virus. Persistence of low level HSV 1 IgM antibodies following post infection over a long period is not uncommon. False positive reaction may occur due to high levels of rheumatoid factor or cross reactivity with HSV 2 & during the course of other viral illnesses. 3. Negative result for Herpes Simplex virus 1 IgM indicates no Herpes Simplex virus 1 infection. False negative reaction may be due to processing of sample collected early in the course of disease or absence of immune response. HSV-1 IgG 1. This assay is used for qualitative detection of specific IgG antibodies to Herpes Simplex virus 1 in serum samples. 2. Positive result indicates past infection with Herpes Simplex virus 1 or administration of HSV 1 immunoglobulins. Pregnant females with positive HSV 1 specific IgG antibodies are considered to be immune and hence risk of transmission of infection to fetus is minimal. 3. Negative result indicates person has not been exposed to Herpes Simplex virus 1 in the past. Patients with negative results in suspected disease should be re-tested after 10-14 days. False negative results can be due to immunosuppression or due to low/undetectable level of IgG antibodies.