[Evaluation of a program for monitoring of nosocomial infections]

The results of two nosocomial infection surveillance programs are presented. They were conducted sequentially during a period of eight months, in a general hospital in Mexico City. The purpose of the study was to evaluate the results of a previously installed program based on the investigation of the incidence of episodes of nosocomial infections through the results of the investigation of the prevalence of these episodes. The observed prevalence and incidence rates and the calculated incidence rate were 23 percent, (127 episodes in 547 patients); 4.52 percent (134 episodes in 2,963 discharges) and 4 percent. The commonest problems detected by both studies were surgical wound and urinary tract infections. Pseudomonas and coagulase negative Staphylococcus were isolated most frequently during each period. It is concluded the system based on the investigation of the incidence of nosocomial infections works adequately in this hospital. The advantages of the design of the prevalence system are discussed, since it permitted the analysis of the infection risk associated to different invasive procedures. The odds ratio for acquiring respiratory infection was 152 (C.I. 95%: 31,732) in patients that underwent tracheostomy, 20 (C.I. 95%: 4 90) in patients with respirator, 34 (C.I. 95%: 8,142) in patients with endotracheal tube and 33 (C.I. 95%: 8,137) in patients with nasogastric tubes.