Newborn Listeriosis

Contrary to the mild symptoms of maternal listeriosis, neonatal infection caused by L. monocytogenes is a serious, often fatal disease. Neonatal listeriosis is divided into two clinical forms, early and late onset.

• Early onset: it occurs in newborns infected in utero within the first week of birth, often within the first 24 to 48 hours. 45-70% of neonatal listeriosis is early onset. The transmission route is transplacental, with miliary dissemination of L. monocytogenes in the various organs and systems, causing sepsis rather than meningitis. Less common is infantiseptic granulomatosis, a syndrome characterized by disseminated abscesses or granulomas in internal organs (liver, spleen, lungs, kidneys, brain). In this syndrome, the amniotic fluid is brown and infants usually present with low birth weight, show signs of sepsis with circulatory, respiratory failure, or both. Early onset neonatal listeriosis can be complicated by meconium aspiration resulting in respiratory complication, including cyanosis, apnea, and pneumonia

• Late onset: occurs one or more weeks after birth

Newborns are born healthy and full-term, to mothers with uncomplicated pregnancies. Like late onset neonatal disease caused by group B streptococci, listeriosis in these newborns manifests as meningitis. The route of transmission is not known; A route of transmission through the birth canal has been hypothesized, although some cases of late-onset neonatal listeriosis occurred after a caesarean section.

The mortality rate in both types of neonatal listeriosis is approximately 25% (15-50% in the case of early-onset listeriosis, and 10-20% in late-onset listeriosis), and hydrocephalus or motor disabilities may occur in both cases.