Herpes Simplex Virus IgG and IgM
Serologic testing for HSV antibody can detect primary or past HSV infections. If primary infection is suspected, blood samples from acute and convalescent phases should be compared. Evidence of past infection can be determined from a single blood sample. To document congenital infections, serum from both mother and infant should be tested. Recurrent HSV infections are not always accompanied by a significant rise in antibody titer. Therefore, serologic tests should not be used routinely to diagnose recurrent HSV infections.
IgM |
IgG |
Interpretation |
Negative |
Negative |
Seronegative |
Positive |
Negative |
Acute Infection |
Positive |
Positive |
Recent Infection or Reactivation |
Negative |
Positive |
Past Infection |
Paired acute and convalescent sera should be tested in parallel. A significant increase in antibody level is indicative of primary infection. The reference value is seronegative:
IgG <1:8 and IgM <1:10. Serologic tests for herpes antibodies do not reliably distinguish HSV1 from HSV2.
Specimen requirement is one SST tube of blood.