Acinetobacter baumannii infections in a surgical intensive care unit: predictors of multi-drug resistance.
ABSTRACT This study was designed to evaluate Acinetobacter baumannii infections incidence in our Surgical Intensive Care Unit, clinical features and outcome of these patients, and multi-resistance incidence to identify predictors of such a resistance.
Prospective study of all patients with ICU-acquired Acinetobacter baumannii infection from June 1, 2003 to May 31, 2005. Patients with multi-resistant infection, susceptible exclusively to colistin, were compared with those sustaining non-multi-drug resistant infection.
Among 411 patients, 52 (12.6%) developed Acinetobacter infection. Their mean age was 66.3 +/- 8.4 years and APACHE II 20.4 +/- 7.3 (men: 51.9%). Infection sites were: bloodstream (46.2%), respiratory tract (32.7%), central venous catheter (11.5%), surgical site (7.7%), and urinary tract (1.9%). High multi-resistance (44.2%), morbidity (63.4%), and mortality (44.2%) were identified. Colistin was the most effective antibiotic (100% susceptibility), whereas resistance against all other antibiotics was >60%. Previous septic shock (p = 0.04), previous adult respiratory distress syndrome (ARDS) (p = 0.01), number of previous antibiotics (p = 0.01), previous aminoglycoside use (p = 0.04), and reoperation (p = 0.01) were risk factors for multi-resistance in univariate analysis. Morbidity in the multi-resistant group was significantly higher than the non-multi-resistant group (82.6% vs. 48.2%, p = 0.02). Mortality in the multi-resistant group also was higher; however, this difference did not marginally reach statistical significance (60.8% vs. 31.1%, p = 0.06). Multivariate analysis identified previous septic shock (p = 0.04; odds ratio (OR), 9.83; 95% confidence interval (CI), 1.003-96.29) and reoperation (p = 0.01; OR, 8.45; 95% CI, 1.52-46.85) as independent predictors of multi-resistance.
Acinetobacter baumannii infections are frequent and associated with high morbidity, mortality, and multi-resistance. Avoidance of unnecessary antibiotics is a high priority, and specific attention should be paid to patients with previous ARDS and, particularly, previous septic shock and reoperation. When such risk factors are identified, colistin may be the only appropriate treatment.
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ABSTRACT: To determine epidemiology and risk factors for nosocomial infections in intensive care unit (ICU). DESIGN. Prospective incidence survey. An adult general ICU in a university hospital in western Turkey. All patients who stayed more than 48 h in ICU during a 2-year period (2000-2001). The study included 434 patients (7394 patient-days). A total of 225 infections were identified in 113 patients (26%). The incidence and infection rates were 56.8 in 1000-patient days and 51.8%, respectively. The infections were pneumonia (40.9%), bloodstream (30.2%), urinary tract (23.6%) and surgical site infections (5.3%). Pseudomonas aeruginosa (22.6%), methicillin-resistant Staphylococcus aureus (22.2%) and Acinetobacter spp. (11.9%) were frequently isolated micro-organisms. Median length of stay with nosocomial infection and without were 13 days (Interquartile range, IQR, 20) and 2 days (IQR, 2), respectively ( P<0.0001). In logistic regression analysis, mechanical ventilation [odds ratio (OR): 16.35; 95% confidence interval (CI): 8.26-32.34; P<0.0001), coma (OR: 15.04; 95% CI: 3.41-66.33; P=0.0003), trauma (OR: 10.27; 95% CI: 2.34-45.01; P=0.002), nasogastric tube (OR: 2.94; 95% CI: 1.47-5.90; P=0.002), tracheotomy (OR: 5.77; 95% CI: 1.10-30.20; P=0.04) and APACHE II scores 10-19 (OR: 10.80; 95% CI: 1.10-106.01; P=0.04) were found to be significant risk factors for nosocomial infection. Rate of nosocomial infection increased with the number of risk factors (P<0.0001). Mortality rates were higher in infected patients than in non-infected patients (60.9 vs 22.1%; P<0.0001). These data suggest that, in addition to underlying clinical conditions, some invasive procedures can be independent risk factors for nosocomial infection in ICU.Intensive Care Medicine 10/2003; 29(9):1482-8. · 5.26 Impact Factor
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ABSTRACT: Acinetobacter baumannii has become an increasingly important nosocomial pathogen, particularly in intensive care units (ICUs). The aim of this investigation was to study the molecular epidemiology of A baumanii in a university hospital in Italy. All A baumanii isolates were collected and typed with phenotypic and genotypic methods during a 7-month period. A 1-year prospective surveillance of ICU-acquired infections was performed by using the National Nosocomial Infections Surveillance methodology. A baumanni accounted for 28.4% of all infections and 46.7% of all pneumonia acquired in the ICU, with a nosocomial infection rate of 12.4% or 8 infections per 1000 patient-days. Risk factors for A baumannii acquisition in the ICU were mechanical ventilation and previous use of broad-spectrum antibiotics, whereas administration of carbapenems showed a significant protective effect. Pulsed-field gel electrophoresis of genomic Apa I digests identified at least 5 outbreaks in the ICU caused by 5 different clones, one replacing the other in a well-defined temporal order. Whereas the sequential temporal cluster of epidemic clones in the ICU is intriguing and requires further research, the clear evidence of cross-contamination of A baumannii isolates involved with infections in the ICU demands extensive preventive efforts.American Journal of Infection Control 07/1999; 27(3):247-53. · 2.73 Impact Factor
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ABSTRACT: A nosocomial outbreak of infections due to imipenem-resistant Acinetobacter baumannii occurred in a New York hospital after increased use of imipenem for cephalosporin-resistant klebsiella infections. We identified all A baumannii isolates over 12 months, reviewed corresponding patient records, and compared strains with different antibiotic susceptibility patterns by restriction endonuclease analysis. Environmental surveillance cultures were done before and after institution of control measures. 59 patients harboured imipenem-resistant A baumannii, and 18 were infected. Isolates from patients were resistant to all routinely tested antibiotics, including imipenem. Further studies showed susceptibility to polymyxin B and sulbactam. These isolates were identical by restriction endonuclease analysis to A baumannii isolates susceptible to imipenem alone, or to imipenem and amikacin, but differed from broadly susceptible isolates. Surveillance cultures showed hand and environmental colonisation by imipenem-resistant strains. Infection and colonisation were eliminated by intensive infection control measures, and irrigation of wounds with polymyxin B. Increased use of imipenem against cephalosporin-resistant klebsiella may lead to imipenem resistance among other species, particularly acinetobacter. Such resistance appears to derive from a prior multi-resistant clone, in contrast to one which retains susceptibility to several antibiotics.The Lancet 12/1994; 344(8933):1329-32. · 39.06 Impact Factor