Characteristics of neonatal herpes simplex virus infections in Germany: results of a 2-year prospective nationwide surveillance study

OBJECTIVE: To assess incidence and burden of neonatal herpes simplex virus (HSV) infections and to explore possible transmission routes. METHODS: A 2-year prospective nationwide surveillance study performed in 2017 and 2018. All German paediatric departments (n=464 in 2017, n=441 in 2018) were contacted on a monthly basis to report potential cases of neonatal HSV infections. Infants with a postnatal age of ≤60 days and a positive HSV PCR or HSV culture from skin, mucous membrane, vesicles or conjunctival smear, blood or cerebrospinal fluid were included in the study. RESULTS: 37 cases were analysed. 29 patients who exhibited no or only mild clinical symptoms were discharged home without organ damage or neurological abnormalities. Four patients showed significant neurological impairment, one patient required liver transplantation and two patients died during in-patient treatment. The 2-year incidence of neonatal HSV infections was 2.35 per 100 000 live births (95% CI 1.69 to 3.02) and disease-specific mortality was 0.13 per 100 000 live births (95% CI 0.04 to 0.21). Data on possible transmission routes were available in 23 cases. In 20 cases, an orofacial HSV infection was present in one or more family members. An active maternal genital HSV infection was reported in 3 cases. CONCLUSION: Neonatal HSV infections are rare in Germany. Most infants have a benign clinical course, but some infants are severely affected. Postnatal HSV exposure may account for a considerable number of neonatal HSV infections.