Herpes Simplex Virus 1 infection: misleading findings in an infant with disseminated disease.

Neonatal Herpes Simplex Virus (HSV) infection is a serious illness with significant mortality and morbidity for disseminated disease. Clinical diagnosis of neonatal HSV infection is often difficult without evidence of HSV exposure, for example, absence of a rash or the presence of non-specified manifestations in an infant. Early recognition and treatment with high-dose Acyclovir may dramatically improve the short and long-term outcomes. We describe an infant with disseminated disease due to HSV-1 infection, who first presented clinical and radiologic features of pneumonia. The diagnosis was performed post-mortem by Real-Time Polymerase Chain Reaction (PCR) analysis of blood, cerebrospinal fluid and pleural liquid of the infant. Tissue PCR revealed a disseminated HSV-1 infection, with a high viral load detected in liver, lungs, brain, heart, striated muscle, kidneys, and thymus tissues. This case report highlights the need for neonatologists to raise awareness about the different clinical manifestations of disseminated neonatal HSV infection. HSV infections should be prominent in the differential diagnosis of an infant under four weeks of age with fever, pneumonia, unexplained seizures or sepsis-like disease, particularly if unresponsive to antibiotics. Early initiation of appropriate antiviral therapy for high-risk infants undergoing testing for HSV infection can be essential to prevent significant morbidity and mortality.