Evaluation of suspected neonatal herpes simplex virus infection in preterm versus term newborns in the neonatal intensive care unit.

BACKGROUND: While national guidelines are available for the evaluation and management of term infants at risk for herpes simplex virus (HSV) infection, such guidelines are lacking for preterm infants. We sought to determine the risk factors and clinical characteristics of preterm vs. term infants who were evaluated and treated empirically for HSV infection in the neonatal intensive care unit (NICU).

METHODS: In a retrospective cohort study, medical records of all infants who were admitted to our NICU (2009-2016) and who were evaluated and empirically treated for HSV were reviewed for mothers' and infants' demographics, clinical characteristics, and laboratory findings.

RESULTS: During the study period 4.2% (103/2,471) of all preterm infants, and 6.0% (112/1,865) of all term infants were evaluated and treated empirically for neonatal HSV. Among all infants who were evaluated and treated for HSV, 5.5% (12/215) had neonatal HSV disease, of whom 83.3% (10/12) were preterm infants. In comparison to term, preterm infants were more likely to be evaluated and treated, if they had a maternal history of HSV [OR 2.51 (95% CI: 1.41-4.48)], prolonged rupture of membranes [2.64 (1.221-5.73)], leukopenia [3.65 (1.94-6.87)] and thrombocytopenia [2.25 (0.85-5.89)]. HSV disease was associated with a higher mortality compared to those without disease [25% (3/12) vs. 4.4% (9/203) respectively; p = <0.05].

CONCLUSION: Preterm infants evaluated and empirically treated for HSV have a higher burden of HSV infection than term infants. HSV should be considered in the management of preterm infant with a maternal history of HSV, prolonged rupture of membranes, and thrombocytopenia.