Background:
An estimated one in five Americans (45 million) over the age of 14 years are infected with HSV-2; 90% of these are unaware of their diagnosis, either because they have no symptoms or because symptoms are unrecognized (Xu, 2004; Fleming, 1997). Asymptomatic viral shedding is considered to be the primary means of transmitting genital herpes to sexual partners and neonates (Mertz, 1992; Brown, 1992). Thus, the management of HSV-2 infection has shifted to treating those infected with HSV-2, rather than those with recognizable symptoms only. We conducted a randomized, placebo controlled, crossover study to investigate the effect of VALTREX® 1g once daily for 60 days on viral shedding in HSV-2 seropositive subjects with no previous history of symptomatic genital herpes infection.
Anecdotal information suggested more than 50% of patients with a “low-positive” result (index value >1.1 and ≤ 3.5) via the Focus Diagnostics HerpeSelect® -2 ELISA glycoprotein G-based assays, test negative for HSV-2 via Western Blot.

Objective:
Because of concern for false positive results in this asymptomatic population and the impact an inaccurate diagnosis may have on a patient's psychosocial status, the Focus Diagnostics HSV-2 IgG Inhibition Assay (IA) was evaluated as a confirmatory test for low-positive HSV-2 results via HerpeSelect-2 ELISA.

Method:
Of the 73 subjects randomized into the study, 25 (34%) subjects had a low positive result via the HerpeSelect HSV-2 ELISA. Twenty-nine (29) samples were reflex tested via IA.

Result:
Positive results were confirmed in 22 (76%) samples; 2 (7%) samples were negative, 4 (14%) were unevaluable, and one sample was not tested.

Conclusion:
In this small study of asymptomatic subjects, the Focus Diagnostics HSV-2 IgG Inhibition Assay was an effective, supplemental tool to confirm the presence or absence of genital herpes infection.

Implications:
Confirmatory testing for HSV-2 via the IA increases accuracy in the diagnosis of genital herpes.