Neonatal cross-infection due to Listeria monocytogenes

Neonatal listeriosis is rare and detecting more than one case together would be unlikely without a causal link. Thirty-five instances of neonatal listeriosis where cross-infection occurred in the UK and Ireland were reviewed together with 29 other similar episodes reported elsewhere. All instances comprised an infant who was ill at or within one day of delivery and who had direct or indirect contact with a second infant, or in the minority, two or more infants, who then usually developed meningitis 6 to 12 days later. In most instances, the infants were nursed on the same day in obstetric units or new-born nurseries and consequently, staff and equipment were common: hence, the likely route of transmission was via direct or indirect neonate to neonate contact. In one instance, a stethoscope was used on both infants nursed in different parts of the same hospital. In a further incident, the mother of the early-onset infant cuddled a baby from an adjacent bed who developed meningitis 12 days later. The largest outbreak occurred in Costa Rica where nine neonatal listeriosis cases resulted after bathing in mineral-oil shortly after birth which had been contaminated from the early-onset index case.

Automated summary

Neonatal listeriosis is a rare infection, and the likelihood of detecting multiple cases without a causal link is low. This study reviewed 35 cases of neonatal listeriosis with cross-infection in the UK and Ireland, as well as 29 similar episodes reported elsewhere. Most cases involved infants who became ill on the day of delivery or within one day and had contact with another infant, leading to the development of meningitis in the second infant after 6 to 12 days. The likely route of transmission was through direct or indirect contact between neonates.