Bacteremia due to Acinetobacter baumannii epidemiology, clinical findings, and prognostic features

The number of nosocomial infections caused by Acinetobacter baumannii has increased in recent years. During a 12-month study, there were 1.8 episodes of A. baumannii bacteremia per 1,000 adults admitted to a hospital in Seville, Spain. Seventy-nine patients were included in the study. A. baumannii bacteremia occurred after a mean (+/- SD) hospitalization of 18 +/- 20 days. In all cases the infections were acquired nosocomially; 71% were acquired in intensive care units. Ampicillin/sulbactam was found to be the most active agent against A. baumannii. The most common source of the bacteremia was the respiratory tract (32 cases [71%]). Twenty patients (25%) had septic shock, and 24 (30%) had disseminated intravascular coagulation (DIC). Treatment with imipenem or ampicillin/sulbactam was most effective (cure rates, 87.5% and 83%, respectively). The deaths of 27 patients (34%) were related to A. baumannii bacteremia. The presence of DIC (odds ratio [OR] = 116.4; P < .0001) and inappropriate antimicrobial treatment (OR = 15.2; P < .01) were independently associated with mortality. We conclude that most A. baumannii isolates are multiresistant and that nosocomial A. baumannii bacteremia may cause severe clinical disease that is associated with a high mortality.