Relapse of neonatal herpes simplex virus infection

Background: Neonatal herpes simplex virus (HSV) infection is a severe disease with high mortality and morbidity. Recurrence of skin vesicles is common. Objective: To determine the features of relapse and identify the factors related to relapse. Design: Thirty two surviving patients with neonatal herpes virus infections were enrolled. All patients received acyclovir treatment. Clinical and virological data were analysed and compared between relapsed and non-relapsed cases. Results: Thirteen (41%) had either local skin or central nervous system relapse between 4 and 63 days after completing the initial antiviral treatment. Nine patients exhibited local skin relapses, and four developed central nervous system relapses. In one skin and two central nervous system relapse cases, neurological impairment later developed. Type 2 virus infection was significantly related to relapse (odds ratio 10.4, 95% confidence interval 1.1 to 99.0). Patients with relapse had worse outcomes than those without relapse. Conclusion: Neonates with HSV type 2 infections have a greater risk of relapse. Relapsed patients have poorer prognoses.