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Should Universal Type-Specific HSV Screening in Pregnancy Be Implemented?

YES David A. Baker, MD   Current ACOG guidelines recommend relying on history to screen for the risk of herpes simplex virus (HSV) transmission to the neonate. However, history alone misses up to 80% of women with genital HSV infections.1 These outdated guidelines must be revised. The only way to determine risk is to screen both partners with type-specific serologic testing during early pregnancy. This will identify both infected and susceptible pregnant women. Such tests are now readily available, and are more accurate and convenient than ever—offering sensitivity of 92% to 100% and specificity of 87% to 98% for HSV-2. Why use serologic screening for HSV in pregnancy? As with history, demographic and clinical factors are likewise not reliable surrogates. In addition, there is a high incidence of asymptomatic genital HSV; approximately 70% of infected infants are born to women who are asymptomatic at delivery and have no history of HSV.1 Serologic screening will identify the pregnant women most at risk of transmission—ie, the serodiscordant women who acquire HSV-1 or-2 from their partners during pregnancy. Since the publication of ACOG's guidelines in 1999, it has been found that 22% of pregnant women are seropositive for HSV-2, and more than 2% of women acquire HSV during pregnancy.1 The annual incidence is estimated at 1,500 cases in the United States—rising to 1 in 3,200 live births in some areas.1 Serologic testing can confirm clinical diagnoses, detect asymptomatic infection, and help manage partners of infected patients. And finally, it also addresses the high false-negative rate for cultures. With testing to identify at-risk and infected pregnant women, preventive strategies can be initiated. If a mother is identified as susceptible, condom use with pharmacologic suppression can be implemented for her partner. If an infected mother is identified, the hospital staff can be alerted to the potential for neonatal infection. Furthermore, preliminary studies suggest that antiviral suppression in infected women during the last weeks of pregnancy is a safe, practical, and cost-effective preventive intervention, decreasing clinical recurrences, viral shedding at delivery, and need for cesarean delivery.2 It is time to address neonatal HSV infection in the United States. The best tool available to accomplish this is accurate, reliable serologic testing for all pregnant women. David A. Baker, MD, is Professor, Obstetrics, Gynecology, and Reproductive Medicine, and Director, Division of Infectious Diseases, Health Sciences Center, Stony Brook University Medical Center. Stony Brook, N Y. References Brown ZA, Gardella C, Wald A, Morrow RA, Corey L. Genital herpes complicating pregnancy. Obstet Gynecol. 2005;106(4):845-856. Sheffield J, Hill JB, Hollier LM, Laibl VR, Roberts SW, Sanchez, PJ, Wendel GD. Valacyclovir Prophylaxis to Prevent Recurrent Herpes at Delivery: A Randomized Clinical Trial. Obstet Gynecol 2006;108(1):141-147.

NO Alan T. N. Tita, MD, PhD   Neonatal herpes is a devastating consequence of genital herpes simplex virus (HSV) infection. Both types 1 and 2 are highly prevalent, with 20% to 30% of pregnant women in the United States testing positive for HSV-2. Current preventive interventions against neonatal herpes include antivirals to prevent peripartum outbreaks in women with known infection, and cesarean delivery for those with active lesions in labor. However, most cases of neonatal herpes occur in mothers with no history of infection or active lesions—ie, new peripartum genital HSV. As type-specific serology can more reliably determine existing infection or susceptibility, proponents argue that universal antenatal HSV screening can effectively prevent neonatal herpes by identifying both women with existing infection, and susceptible (seronegative) women (and their partners) who require preventive counseling. Nevertheless, ACOG, the American Academy of Pediatricians, and the Centers for Disease Control and Prevention do not recommend universal HSV screening during pregnancy. The US Preventive Services Task Force actively recommends against routine serologic screening of asymptomatic pregnant women.1 Indeed, universal screening is problematic from the perspectives of both the individual patient and the general public.2 Principles of good screening require that effective interventions be available for those found to be at risk. However, proposed HSV interventions—including counseling of susceptible women to practice celibacy or safe sex during the third trimester—are not proven effective in preventing neonatal herpes. On the contrary, data suggest that many susceptible women do not abstain, and few partners submit to HSV testing. Therefore, confirmation of effective preventive interventions must precede routine screening. In addition, although neonatal HSV reportedly occurs in 1/3,200 live births in one regional population in the United States, the actual incidence may be as low as 1/20,000—which is more consistent with rates in other developed countries (eg, 1/18,000 in Canada, 1/60,000 in the United Kingdom). These data suggest that neonatal herpes is indeed a rare event—ie, as low as 300 US cases per year—for which routine screening is not warranted. Finally, it is not known what impact (if any) routine screening has on health outcomes such as cesarean delivery, psychosocial well-being, and invasive newborn testing. Screening would identify millions of women infected with HSV, including asymptomatic women who are at very low risk of recurrence and vertical transmission. Labeling these women as HSV-positive could lead to unnecessary treatment, cesarean delivery, anxiety, and conflict with partners for little discernible benefit. Finally, 4 out of 5 studies have concluded that routine screening is not cost-effective; the only favorable study was industry-funded. Universal testing for HSV in pregnancy does not meet the key criteria for effective screening, and should not be undertaken simply because improved serologic testing is available. Alan T. N. Tita, MD, PhD, is Instructor and Fellow, Division of Maternal-Fetal Medicine & Center for Women’s Reproductive Health, Department of Obstetrics and Gynecology, School of Medicine, University of Alabama at Birmingham. References US Preventive Services Task Force. Screening for Genital Herpes: Recommendation Statement. AHRQ Publication No. 05-0573-A, March 2005. Agency for Healthcare Research and Quality, Rockville, MD. www.ahrq.gov/clinic/ uspstf05/herpes/herpesrs.htm. Accessed September 18, 2007. Tita AT, Grobman WA, Rouse DJ. Antenatal herpes serologic screening: an appraisal of the evidence. Obstet Gynecol. 2006;108(5):1247-1253.