This study objective was to perform an epidemiologic analysis of bacterial hospital infections (HI) in newborn infants (NB) admitted to an university hospital NICU from 01/05/94 to 31-05-96.

174 NB with any type of HI were studied. HI were defined by the National Infections Surveillance System (CDC-Atlanta), as any infection presented by the NB during the hospital stay, with exception of transplacental infections. Patients were divided by birthweight (BW) in 4 groups : <1000g (29 RN), 1000-1500g (71 NB), 1501-2500g (53 NB), >2500g (21 NB). HI rates were expressed by accumulated incidence of HI (infected NB/100 admissions) and by infection incidence density (HI/1000 patients- day). Epidemic outbreaks were defined when average HI rates during the study period exceeded 1.96 standard deviation. Association of risk factors (mechanical ventilation, umbilical artery lines, parenteral nutrition and blood products use) with sepsis, pneumonia, necrotizing enterocolitis (NCE), and meningitis were tested by X-square test. Among the 174 infected NB, 304 HI were noted : 53 early infections (≤ 48h of life) and 251 late infections. The acummulated incidence of HI were 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. Epidemic 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. epidermitis, 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 1000-1500g during perenteral nutrition support, and it was frequent in these groups 48h and 7 days after parenteral nutrition interruption.

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