Primary herpes simplex pneumonia in a neonate.

A 6-day-old male infant was treated for rapidly progressive pneumonia. The infection was not responsive to antibiotic and symptomatic treatment, and the infant died within 48 hours of admission. Herpes simplex type II grew from premortem respiratory and postmortem lung cultures, and immunoperoxidase staining confirmed the presence of this organism in lung tissue. Pathologic findings were limited to the lungs. A maternal origin for the virus was suspected but could not be proved. We believe this patient represents the first reported case of isolated herpes simplex type II pneumonia in a neonate.