[Epidemiology of hospital-acquired infections in an adult intensive care unit: results of a prospective cohort study].

OBJECTIVE: We aimed to describe the pattern of nosocomial infections in an adult medical-surgical intensive care unit (ICU).

METHODS: A 2-year prospective cohort study of nosocomial infection surveillance in a 12 - bed adult medical and surgical ICU of the Federico II University Hospital in Naples, was carried out. Data were collected between January 2009 and December 2010 using the standard surveillance protocols and nosocomial infection site definitions of the National Healthcare Safety Network's ICU surveillance component.

RESULTS: Out of 768 patients hospitalized during this period, 434 with an ICU stay longer than 48 h were included in the study. Fifty-three patients acquired a total of 71 nosocomial infections; 55 (77,5%) ventilatorassociated pneumonia (VAP), 10 (14,1%), central-line-associated bloodstream infection (CLA-BSI) and 6 (8,4%) catheter-associated urinary tract infection (CA-UTI). The overall patient day rate was 12,9 patient days. The patient infection rate was 16,3 patients at risk. The mean VAP rate was 15,0/1.000 ventilator days, the CLA-BSI rate 2,9/1.000 central line days and the CA-UTI rate 1,2/1.000 catheter days. Of the nosocomial infections, 65 were Gram-negative, 6 Gram-positive and 5 fungal. The most frequent organism was Acinetobacter baumannii (61,9%), followed by Pseudomonas aeruginosa (22,5%), Enterococcus fecalis (4,2%) and Candida albicans (4,2%). The crude mortality was 35% among ICU-infected patients.

CONCLUSIONS: VAP was the most common nosocomial infection in our ICU. Gram-negative organisms were more commonly reported as etiologic agents of ICU infections.