Sudden unexpected neonatal death due to late onset group B streptococcal sepsis--a case report.

We report a case of sudden unexpected death due to late onset neonatal group B streptococcal sepsis. A male neonate weighing 2731g was born at 35week gestational age, and discharged at the age of 4days after the birth. At 6days after the discharge (10days after the birth), because of consciousness loss and hypothermia, the neonate was conveyed to an emergency hospital, eventually followed by his death. Forensic autopsy revealed neither severe trauma nor cardiac anomaly. Both lungs were edematous. Histopathologically, a lot of bacterial clusters were found in the lungs and intracerebral vessels. Cerebrospinal fluid contained a lot of leukocytes. Streptococcus agalactiae was detected in the specimens from the feces and the blood. Collectively, we diagnosed that the cause of the neonate's death was late onset group B streptococcal sepsis. In autopsy cases of neonates, careful macroscopic and microscopic observations and bacteriological/virological examination should be performed.