Herpes Simplex Type-Specific Serology
Genital herpes simplex virus (HSV) infections are reportedly the most common sexually transmitted disease among women. The seroprevalence of HSV-2 has increased substantially over the last decade, and genital infections due to HSV-1 are becoming more frequent. Differentiation of HSV-1 from HSV-2 is important prognostically, since genital HSV-2 infection is twice as likely to reactivate and recurs 8-10 times more frequently than genital HSV-1 infections. Recurrence of genital HSV-1 is rare after the first year of infection. Acquisition of new HSV-1 infection in an individual with HSV-2 antibodies is unusual, however women with genital HSV-1 infection are still at risk for HSV-2 acquisition.
The American College of Obstetrics and Gynecology recently released Clinical Management Guidelines for Herpes Simplex Infections (ACOG Practice Bulletin #57, 11/04). In women with new or recurrent genital ulcers, PCR testing is 1.5 to 4 times more sensitive than culture for diagnosis. In the absence of lesions, or when PCR is negative despite high clinical suspicion, type-specific antibody testing is recommended. IgG antibody to HSV is detectable 2-12 weeks after infection and persists indefinitely. Only tests based on detection of antibody to HSV glycoprotein G-2 are type-specific due to cross-reactivity between viruses. Compared to Western blot, the sensitivity of type-specific HSV antibodies is 96-100%, with a specificity of 97-98%. It is also recommended that women who have partners with genital herpes should be tested with type-specific serology to assess risk of infection.
