Optimal guidelines needed for preventing neonatal herpes simplex virus

The incidence of neonatal herpes simplex virus ranges from as low as eight cases to as high as 60 cases per 100,000 live births in the United States, and only about 40% of untreated infants with the infection survive — yet evidence-based guidelines for preventing the disease do not exist.

“Current guidelines issued by the American College of Obstetrics and Gynecology provide useful treatment tools but are not directed at the prevention of neonatal HSV infection, and they appear not to have altered the epidemiologic patterns of neonatal HSV infection in the United States in the past decade,” researchers wrote.

Mothers who acquire genital HSV type 1 or 2 during pregnancy are more likely to pass the virus on to their child (25%-50%) than those with longstanding infections that have reactivated at term (<1%), and these differences contribute to “divergent patient care and public health strategies,” according to the researchers.

They advocated that the following proposed strategies be evaluated further to determine their efficacy:

Counseling all women to avoid unprotected sexual intercourse and oral–genital contact during late pregnancy.
Performing serologic testing among pregnant women to determine those at risk for HSV.
Performing serological testing in pregnant women and their partners to determine discordant results that may put an uninfected mother at risk.
Treating pregnant women with recently acquired HSV with an antiviral to reduce the risk for morbidity. Proposed regimens include a 400-mg dose of oral acyclovir (Zovirax, GlaxoSmithKline) three times daily or 500 mg of oral valacyclovir (Valtrex, GlaxoSmithKline) twice a day for seven to 10 days.
Using rapid polymerase chain reaction assays to detect viral shedding at delivery, followed by early antiviral therapy for at-risk infants.

Several potentially problematic areas include the impracticality for busy physicians to provide counseling for patients with previously existing but newly recognized infections; lack of data to determine whether antiviral therapy actually reduces rates of neonatal infection; the large number of patients who would need to be assigned to antiviral therapy to prevent a single case of HSV; and potential adverse events that could result when treating infants with an antiviral.

“A concentrated effort to conduct studies that may provide guidance for effectively reducing the incidence of neonatal HSV infection is needed and will require an alliance between practitioners and academicians,” the researchers wrote.

Corey L. N Engl J Med. 2009;361:1376-1385.

Corey and Wald are among the top herpes virologists in the world, and this review concisely illustrates the ongoing challenges that we face in the prevention and management of neonatal HSV disease. I hope that articles such as this will help put perinatal HSV in the forefront of unmet medical needs in people’s minds. Their call for guidance from professional societies is being answered by the American Academy of Pediatrics, which currently is discussing a suggested approach to the management of neonates delivered to women with active herpetic lesions.

– David W. Kimberlin, MD

Infectious Diseases in Children Editorial Board