Examining the Evidence
Q Is screening all gravidas for genital herpes cost-effective?
A Yes. Until now, serologic screening of all gravidas unaware of their HSV-2 status was thought to be prohibitively expensive and not suitable for routine obstetric practice. This study indicates otherwise. Serologic screening of women in early pregnancy—with or without screening their partners—and treating those who test positive is the most efficient way to prevent neonatal herpes.
In this carefully constructed decision analysis, Baker and colleagues compared 3 testing scenarios:
- Standard care. No herpes simplex virus type 2 (HSV-2) testing is performed and antiviral therapy is offered only to women who know they have genital herpes.
- Screening all gravidas. All women unaware of their HSV-2 serologic status are screened at 15 weeks’ gestation. Those who test positive are offered antiviral suppressive therapy from 36 weeks’ gestation to the time of labor. Those who test negative are counseled about safe sex in the third trimester.
- Screening all gravidas and their par tners. Gravidas unaware of their HSV-2 status are tested, and their partners are offered screening. Women who test positive are given antiviral therapy from 36 weeks to labor. If their partners test positive, they are offered antiviral therapy.
The second scenario had an incremental cost of $18,680 per infant quality-adjusted life-year gained (QALY), while the third scenario cost $48,956 per QALY gained. Since cost-effectiveness is usually defined as an incremental expense of less than $50,000 per QALY gained, both scenarios met the criterion.
Most people don’t know they’re infected
About 25% of adults in the United States are infected with HSV-2.1 Prevalence of genital herpes is even higher if HSV-1 infection is included. However, less than 10% of persons infected are aware they have the virus. The rest are mildly symptomatic, and usually are treated for recurrent genital complaints attributed to conditions other than genital herpes.2
Unfortunately, neonatal herpes is increasing with the rising prevalence among adults. Women at greatest risk of infecting their newborns are HSV-2 seronegative in early pregnancy, have an HSV-2 seropositive partner, and acquire new HSV-2 infection in the third trimester.
Since 75% to 90% of primary infections are unrecognized by patient and doctor, labor may begin without any external evidence of primary genital HSV infection and result in neonatal infection.
1. Leone P, Fleming DT, Gilsenan AW, et al. Seroprevalence of herpes simplex virus 2 in suburban primary care offices in the United States. Sex Trans Dis. 2004;31:311-316.
2. Wald A, Zeh J, Selke S, et al. Reactivation of genital herpes simplex virus type 2 infection in asymptomatic seropositive persons. N Engl J Med. 2000;342:844-850.