Background

Neonatal Herpes Simplex Virus (HSV) infection may cause severe morbidity and mortality. With cases increasing, optimising short and long-term management for infants is important to minimise complications.

Aciclovir prophylaxis reduces recurrence of central nervous system (CNS) disease, which may occur in up to 8% of cases. Daily prophylaxis over a 6-month period has been shown to improve neurodevelopmental outcomes. We present outcomes and recurrence rates for this treatment course.

Methods

We reviewed neonates under the care of three tertiary centres with HSV disease, who presented at less than 90 days of age. Demographics, including neonatal history, clinical presentation, initial investigations and treatment were reviewed (Table 1). Follow-up, including recurrence rate on and after prophylactic aciclovir or valaciclovir and management were recorded.

Results

Of 21 patients, six (28%) had HSV-1, 14 (66%) HSV-2 and one unknown. 13 infants were born at term, eight preterm (<37 weeks). 57% presented with central nervous system (CNS) disease. Seven (33%) had recurrences on prophylaxis, despite good adherence to treatment, and 13 (61%) after stopping prophylaxis. All recurrences were skin eruptions. Premature babies were more likely to have recurrences than term babies. 50% of preterms versus 23% of term babies had recurrences on prophylaxis. After discontinuing prophylaxis, 75% of preterms versus 53% term babies had recurrences.

Conclusions

In this small cohort of infants with neonatal HSV disease, after a course of prophylaxis there was still frequent recurrence of skin lesions, but reassuringly there was no CNS recurrence. Of note, recurrence appeared more common in babies born prematurely, implying a less effective immune response to HSV. Further research is needed to investigate the ontogeny of the immune response to HSV in infants of different gestations.