Improved obstetrical management and evidence-based peripartum antimicrobial therapy in the last decades reduce the frequency of early-onset neonatal sepsis (EONS) and improve the outcome. The spectrum of the microrganisms is different according to regions, countries and periods of time. Appropriate diagnosis and treatment improve the outcome. However dissociation often occurs between clinical manifestation, laboratory and microbiological findings.
Aims: To determine the incidence of neonatal bacteremia in our hospital, to identify the spectrum of organisms from positive blood cultures (BC), to analyze the correlation between clinical manifestation of EOS and/or laboratory abnormalities.
Patients and methods: This study was carried out at the University Hospital of Obstetrics and Gynecology "Maichin dom"- Sofia for 2012. From all 4081 inborn babies 848 were at risk for maternal-fetal infection. In the first two hours after birth they were screened for EONS using a panel of microbiological probes and laboratory blood tests, followed up the next days. According the guidelines of the Neonatology clinic a standard antibiotic therapy was started. 43 of the screened infants (1.05% of all inborn babies) had positive BC and were enrolled in this study.
Results: Sixteen from the 43 babies with positive BC were with birthweight > 2500g (0.48% from all 3316 life born term infants), 27--with birthweight < 2500g (3.5% from all 765 low birthweight babies), 24 were patients of the NICU (3.8% of all 635 babies admitted at the NICU for 2012). No one died. The following groups of organisms in BC were isolated: 24 BC with coagulase-negative Staphylococci, Methicilline sensitive (MSCoNS)--11 of them without any clinical symptoms and laboratory abnormalities were interpreted as result of contamination, 1 BC with Staphylococcus aureus MS (MSSA), 8 with alpha-Streptococci, 5 with Enterococcus faecalis (1 in combination with MSCoNS), 2 with GBS, 2 with Aerococcus urinae and 2 BC with Listeria monocytogenes. Gram-negative organisms were not found in BC after birth. 30 from the infants with positive BC didn't show any clinical symptom of EONS. 20 of them were without laboratory criteria for infection and were discharged after negative BC control. 10 newborns were with transient elevation of CRP but without clinical symptoms. 13 babies showed clinical symptoms of EOS, 3 of them had transient respiratory failure, but negative laboratory criteria. 10 babies met the clinical and laboratory criteria for EONS; in 8 of them the CRP was significantly elevated. Most critically ill were 3 ELBW and ELGA babies: 2 twins with Listeria and 1 baby with MSSA-EONS.
Conclusions: In our study, CoNS were found to be the most common cause of EONS or bacteremia, low incidence of GBS sepsis was established. Almost the half of the babies with positive BC were asymptomatic and without laboratory data for infection. Elevation of the CRP-value was the most frequent laboratory abnormality in symptomatic infants.