Incidence of nosocomial infections at a neonatal intensive care unit: a six-year surveillance study

Nosocomial infection is a frequent complication in neonatal intensive care units (NICUs) attending patients who require lengthy hospitalization and frequent invasive techniques. This study is part of a prospective surveillance program for nosocomial infection in Spain. All patients admitted to NICUs between June 1999 and March 2005 were observed. CDC criteria were used as the standard definition for nosocomial infection. A total of 1236 neonates (58% male) were admitted during the surveillance period, involving 19,420 days in the NICU. The average birth weight was 1947.6 +/- 1009.5 g and average gestational age was 32.9 +/- 5.4 weeks. The most frequent associated pathology was respiratory distress (23.06%). A total of 316 nosocomial infections were diagnosed in 226 neonates, 76.7% affecting premature neonates (< 1500 g). The most frequent location was bacteremia (56.3%), and there was a predominance of coagulase-negative staphylococci (46.05%). Gram-negative microorganisms were isolated in 32.1% of the cases (Escherichia coli and Pseudomonas aeruginosa were the most frequent pathogens). Overall incidence of nosocomial infection was 25.6%. Overall mortality was 6.6%, with higher mortality in the group with nosocomial infections (8.7%). Nosocomial infection rates are acceptable, with a typical epidemiological pattern for these units. Presence of a central catheter increased the risk. A program to promote proper hand washing should be considered. We do not recommend a continuing surveillance strategy in these units.