This study objective was to perform an epidemiologic analysis of bacterial hospital infections (HI) in inborn newborn infants (NB) admitted to an university hospital NICU from May/94 to May/96.

174 NB with HI in any site were studied. HI were defined by the National Infections Surveillance System (CDC-Atlanta), as any infection presented by the NB during the hospital stay, but the transplacentally infections. Patients were divided by birthweight (BW) in 4 groups: < 1000g (29 RN), 1000-1500g(71 NB), 1501-2500g (23NB), > 2500g (21NB). HI rates were expressed by cumulated incidence of HI (infected NB/100 admissions) and by infections incidence density (HI/1000 pacients-day). Outbreaks were defined when average HI rates during study period exceeded 1.96 standard-deviation. Association of risk factors (mechanical ventilation, umbilical artery, parenteral nutrition, and blood product use) with sepsis, pneumonia, necrotizing enterocolitis(NEC), and meningitis were tested by χ-square test.

Among the 174 infected NB, 304 HI were noted: 53 early infections (≤48h of life) and 251 late infections. The cumulated incidence of HI was 26 in the general NB population, 57 in < 1000g NB, 59 in NB with BW of 1000-1500g, 20 in NB with BW of 1501-2500g, and 9 in >2500g NB. The infections incidence density was 23 in the general population, 25 in < 1000g NB, 26 in NB with BW of 1000-1500g, 22 in NB with BW of 1501-2500g, and 15 in > 2500g NB. Outbreaks of HI were noted during Feb & Dec/94 and Feb/95. Sepsis, omphalitis, skin infections and NEC were the most frequent infections during the study period. The main bacteria responsible for those infections were:S. epidermidis, S. aureus and Enterobacter spp. Pneumonia was associated with mechanical ventilation in NB with BW of 1000-1500g. NEC was less frequent in the study population and in NB with BW 1000-1500g during parenteral nutrition support, and it was more frequent in these groups 48h and 7 days after parenteral nutrition interruption.

NICU continuous epidemiologic analysis in developing countries is important to determine target areas for HI surveillance and prevention.