When perinatal asphyxia is not the whole story: neonatal listeriosis masquerading as hypoxic-ischemic encephalopathy

Neonatal listeriosis is an uncommon but potentially life-threatening cause of early-onset sepsis that can closely resemble hypoxic-ischemic encephalopathy. We present a term male infant delivered by cesarean section for nonreassuring fetal heart rate tracing who required resuscitation with positive pressure ventilation. Severe metabolic acidosis and low Apgar scores initially suggested perinatal asphyxia; however, a structured neurologic examination at 1 and 3 hours of life did not meet criteria for therapeutic hypothermia, and the infant subsequently developed fever, thrombocytopenia, persistent shock, and marked transaminitis. Blood and placental cultures grew Listeria monocytogenes, a gram-positive bacillus. The infant improved with ampicillin monotherapy and was discharged with a normal neurologic examination. This case illustrates the importance of maintaining a broad differential diagnosis, including infection, in neonates with a presumed diagnosis of perinatal asphyxia.