From the Guidelines
The sensitivity of Herpes Simplex Virus (HSV) serology is estimated to be around 70.2% for HSV-1 and 92% for HSV-2, with false-negative tests potentially occurring during the window period of up to 12 weeks after acquisition of the virus. When considering the diagnosis of HSV infection, it's crucial to understand the limitations and characteristics of different testing methods.
- Type-specific HSV serologic assays, such as those targeting glycoprotein G-1 or G-2, are used to differentiate between HSV-1 and HSV-2 infection 1.
- The sensitivity of these assays can vary, with HSV-1 assays lacking sensitivity, which can result in false-negative diagnoses, as seen in a study where the sensitivity for detecting HSV-1 antibodies was 70.2% 1.
- On the other hand, HSV-2 serologic tests have high sensitivity, estimated at 92%, but may lack specificity, particularly with low index values 1.
- Western blot/immunoblot assays are considered the gold standard for HSV serologic testing, targeting antibodies to several HSV antigens, but their availability might be limited in routine clinical settings 1.
- It's essential to consider the timing of the test, as antibodies take time to develop, and false negatives can occur, especially in early infection or in immunocompromised patients 1.
- For optimal diagnosis, serologic testing should be combined with other methods, such as PCR testing of lesions, which has superior sensitivity for detecting virus during outbreaks 1.
From the Research
Sensitivity of Herpes Simplex Virus (HSV) Serology
- The sensitivity of HSV-2 serology was found to be 13.33% and 73.33% in primary and recurrent genital herpes, respectively 2.
- A study comparing commercial methods for detecting type-specific HSV-1 and HSV-2 IgG reported sensitivity values of 98.47% for immunoblot, 99.24% for chemiluminescent immunoassay, and 99.62% for ELISA for HSV-1 3.
- For HSV-2, the sensitivity values were 98.11% for immunoblot, 99.06% for chemiluminescent immunoassay, and 99.06% for ELISA 3.
- Another study reported sensitivity values of 94% for BioPlex HSV-1 IgG and 92% for BioPlex HSV-2 IgG 4.
- However, a study on the limits of reliability of glycoprotein G-based type-specific serologic assays for HSV types 1 and 2 found that the serostatus of some individuals changed from positive to negative over time, with positive-to-negative shifts occurring in every assay tested 5.
- The frequency of these shifts ranged from 6.1% to 21.2% of the specimen sets tested, highlighting the potential for inaccuracy in HSV serology 5.
- Type-specific serology can distinguish between anti-HSV-1 and anti-HSV-2 antibodies, with currently available kits having a sensitivity and specificity of 90 to 100%, depending on the population studied 6.