TABLE 94.6 USUAL RANGES FOR CEREBROSPINAL FLUID PARAMETERS Herpes Simplex Virus, Neonatal CLINICAL PEARLS AND PITFALLS Most mothers of infants with HSV infection not provide a history of HSV, as primary infection can be asymptomatic and vesicular lesions deep in the female genitourinary tract cannot be visualized by the mothers Thus, a “negative” maternal history of herpes does not rule out herpes in an infant HSV has substantial overlap with bacterial causes of sepsis and meningitis The three main forms of neonatal disease are skin, eye, and mouth (SEM) disease, CNS disease, and disseminated disease HSV should be considered in the differential diagnosis of any febrile neonate with a CSF pleocytosis and in infants with elevated hepatic transaminases or coagulopathy Early recognition of HSV disease and prompt initiation of acyclovir can decrease the substantial morbidity and mortality in infants Current Evidence HSV has three major manifestations in the neonatal period HSV genital lesions will be described in the section on sexually transmitted infections (STIs) It is estimated that 45% of adults in the United States are seropositive for HSV-1 and 16% for HSV-2 Both viruses can cause oral or genitourinary infection, but approximately 75% of neonatal HSV disease is caused by HSV-2 In one study, 0.4% of 0- to 60-day-old infants in whom lumbar punctures were performed had HSV infection, with a peak in the 2nd and 3rd weeks of life Neonatal HSV is thought to complicate in 3,200 deliveries, resulting in approximately 1,500 cases/yr in the United States Risk factors for transmission to neonates include primary maternal infection; vaginal delivery; prolonged rupture of membranes; HSV-2; and use of fetal scalp electrodes The risk of neonatal HSV is highest during the primary infection in the mother, as viremia is often higher than with recurrent infections, and an effective immune response has yet to be mounted However, 75% of mothers of HSV-infected neonates did not report a history of herpes, as primary infection can be asymptomatic As such, the lack of maternal history of HSV should not provide false reassurance to the PEM clinician