Herpes Simplex Virus 1 and 2 (IgG), with Reflex to HSV-2 Inhibition - Herpes Simplex Virus (HSV) is responsible for several clinically significant human viral diseases, with severity ranging from inapparent to fatal. Clinical manifestations include genital tract infections, neonatal herpes, meningoencephalitis, keratoconjunctivitis, and gingivostomatitis. There are two HSV serotypes that are closely related antigenically. HSV type 2 is more commonly associated with genital tract and neonatal infections, while HSV type 1 is more commonly associated with infections of non-genital sites. Specific typing is not usually required for diagnosis or treatment. The mean time to seroconversion using the type specific assay is 25 days. The performance of this assay has not been established for use in a pediatric population, for neonatal screening, or for testing of immunocompromised patients.
This assay utilizes recombinant type-specific antigens to differentiate HSV-1 from HSV-2 infections. A index positive result cannot distinguish between recent and past infection. If recent HSV infection is suspected but the results are negative or equivocal, the assay should be repeated in 4-6 weeks.
Confirmation testing with HSV-2 Inhibition on positive initial results vs the Western Blot:
The HSV-2 IgG Western blot assay has historically been considered the gold standard for identifying HSV-2 IgG reactivity. However, Ashley-Morrow et al have clearly demonstrated that the HSV-2 IgG Western blot is less sensitive than the HerpeSelect HSV-2 IgG assay for detecting IgG seroconversion following newly acquired HSV-2 infection: the median interval between symptom onset and IgG seroconversion is 21 days for the HerpeSelect assay versus 68 days for the Western blot assay.3 There is thus a window of approximately 47 days in which the Western blot assay may give false-negative confirmatory results. In contrast, true-positive specimens in this window are positive (>60% inhibition) in the HSV-2 IgG inhibition assay. In addition to increased sensitivity, the turnaround time for the inhibition assay is shorter than that of the Western blot assay.
HSV 1 IgG, Type Specific Ab
HSV 2 IgG, Type Specific Ab
If Herpes Simplex Virus 2 (IgG) is >1.09, then HSV-2 Inhibition Study will be performed
No fasting required.
Estimated turnaround for results is 3 business days. If confirmation testing is required, the estimated time may be extended.