Hospital-acquired infections among surgical patients in a Brazilian hospital.

A historical cohort study was conducted among surgical patients in a large general hospital in Porto Alegre, Brazil between March 1992 and May 1993. Data were collected by means of a retrospective chart review, which followed a standardized method based on the systematic review of all clinical and laboratory information available in the hospital records. The criteria for diagnosis of all hospital-acquired infections (HAIs) were based on those from the Centers for Disease Control, Atlanta. In total, 890 HAIs were detected among the 4199 patients included in the cohort. The incidence rate of HAIs for all sites combined was 21.20%. Incidence rates ranged from 2.95% for bloodstream infections to 8.65% for surgical wound infections. The overall incidence density was 16.32 HAIs per 1000 patient-days. Incidence densities ranged from 2.03 for bloodstream infections to 7.46 per 1000 patient-days for surgical wound infections. The median incubation period for surgical wound infections was seven days, and 29.4% of these infections were detected at post-discharge. Gram-negative bacteria were the most common organisms implicated in HAIs.