Colonization or infection? Why are premature infants and neonates so susceptible?

Incidence of sepsis. Out of 650,000 newborn infants per year in Germany approximately 7,000 (1.1%) of term born infants suffer from neonatal sepsis. Approximately 1.3% of neonates belong to the group of very low birth weight (VLBW) infants with a birth weight <1,500 g who have a 10-fold higher risk of sepsis compared to term infants. Discussion. The complex interplay of intrinsic factors (e. g. adaptation of fetal and maternal immune systems, functional immaturity, small anatomical size and loss of protective measures) and exogenous influences (e.g. intensive care measures) is decisive for the vulnerability of preterm and term infants. This review article focuses on these pathophysiological aspects.