Genital herpes simplex infections: effect of asymptomatic shedding and latency on management of infections in pregnant women and neonates.

Asymptomatic shedding of herpes simplex virus (HSV) at delivery occurred in 2.4% of women with a past history of recurrent genital infections; using current methods, this could not be predicted in advance. In addition, only 22% of the mothers of infected infants had an elicitable history of recurrent genital infections. Passively derived neutralizing antibody titers of 1:106 to HSV-1 and 1:67 to HSV-2 were found in 22 exposed infants who remained asymptomatic as compared with 1:8 and 1:8, respectively, in ill infants, suggesting that transfer of antibody from the mother may be an important host defense. Among treated infants, a more rapid rise in antibody titer was seen in infants receiving adenine arabinoside than in those receiving acyclovir; two of the latter infants developed a severe infection in a second organ following cessation of the drug. Exposure of infants to HSV appears inevitable at this time. The extreme variability in outcome is probably related to host factors that are poorly understood at present.