Aim: The objective of this study was to investigate the incidence, causes, the risk factors, etiologic agents and the outcomes of early-onset infections (EOIs) in very-low-birth-weight newborns in Polish neonatal intensive care units.
Methods: Continuous prospective infection surveillance conducted during 2009 at 6 Polish neonatal intensive care units and included 910 newborns whose birth weight was lower than 1500 g. Infections were defined according to the Gastmeier's criteria. EOIs were diagnosed <3 days after delivery.
Results: The frequency of early-onset septicemia (EOS) was 7.0% and of early-onset pneumonia (EO-pneumonia) 8.6%. The factors significantly increasing the risk of EOS were low gestational age, small birth weight, low score in the Clinical Risk Index for Babies and Apgar score as well as maternal chorioamnionitis. The perinatal prophylaxis did not have an influence on the occurrence of EOS. The factors considerably increasing the risk of EO-pneumonia were low scores in the Clinical Risk Index for Babies and Apgar scores, a low gestational age and bacterial vaginosis in the child's mother during pregnancy. The most important etiologic organisms were Gram-positive cocci (39.7% of all the infections, 47.8% in EOS), Streptococcus agalactiae (20% of the EOS), Gram-negative bacilli (33.3% isolates), yeast-like fungi (isolated in 7.9% of cases) and atypical bacteria (22% of the cases of EO-pneumonia).
Conclusions: The observed frequency of EOS did not differ from the one described in the literature, whereas the frequency of EO-pneumonia was higher. The bacterial etiologies suggest the vertical transmission of the pathogens and a close relationship between the observed EOIs with maternal environment. The applied perinatal antibiotic prophylaxis was ineffective.