Clinical features and epidemiology of Acinectobacter baumannii colonization and infection in Spanish hospitals

OBJECTIVE: To investigate the clinical features and the epidemiology of Acinetobacter baumannii in Spanish hospitals. DESIGN: Prospective multicenter cohort study. SETTING: Twenty-seven general hospitals and one paraplegic center in Spain. METHODS: All cases of A. baumannii colonization or infection detected by clinical samples during November 2000 were included. Isolates were identified using phenotypic and genotypic methods. The molecular relatedness of the isolates was assessed by pulsed-field gel electrophoresis. RESULTS: Twenty-five (89%) of the hospitals had 221 cases (pooled rate in general hospitals, 0.39 case per 1,000 patient-days; range, 0 to 1.17). The rate was highest in intensive care units (ICUs). Only 3 cases were pediatric. The mean age of the patients in the general hospitals was 63 years; 69% had a chronic underlying disease and 80% had previously received antimicrobial treatment. Fifty-three percent of the patients had an infection (respiratory tract, 51%; surgical site, 16%; and urinary tract, 11%). Crude mortality was higher in infected than in colonized patients (27% vs 10%; relative risk, 1.56; 95% confidence interval, 1.2 to 2.0; P =.003). Molecular analysis disclosed 79 different clones. In most hospitals, a predominant epidemic clone coexisted with other sporadic clones. Imipenem resistance was present in 39% of the hospitals. CONCLUSIONS: A. baumannii was present in most participating Spanish hospitals (particularly in ICUs) with different rates among them. The organisms mainly affected predisposed patients; half of them were only colonized. Epidemic and sporadic clones coexisted in many centers.