Clinical features, risk factors, and outcome of carbapenem-resistant Acinetobacter baumannii bacteremia in a Thai neonatal intensive care unit

Abstract

Background: Carbapenem-resistant Acinetobacter baumannii (CRAB) infection have been increasingly observed and are associated with mortality in neonatal population. Objective: We determined risk factors for and outcome of bacteremia caused by CRAB in neonates. Methods: The clinical data of neonates who developed A. baumannii bacteremia from January 2005 to December 2010 were retrospectively reviewed. Results: During the study period, 22 neonates developed A. baumannii bacteremia, 13 were CRAB at an incidence of 0.5 case/1000 patients-day. Compared with carbapenem-sensitive A. baumannii (CSAB), patients with CRAB bacteremia had lower birth weight, lower gestational age and were more often receiving mechanical ventilation at the onset of bacteremia. Most of the CSAB isolates were susceptible to cefoperazone/sulbactam (89%) and aminoglycosides (50-75%). In contrast, CRAB strains were all resistant to cephalosporins, carbapenems, quinolones, with 39% susceptible to cefoperazone/sulbactam and 8% susceptible to amikacin. Most cases of CRAB bacteremia were treated with cefoperazone/sulbactam or meropenem and in some cases, with the addition of colistin. The all cause morality rates were 54% in CRAB and 11% in CSAB bacteremia, respectively (p = 0.07). Conclusions: Neonatal bacteremia caused by A. baumannii was not common but caused high mortality, particularly from CRAB. Lack of effective antibiotics was the major challenge in treating these patients. Keywords: Acinetobacter baumannii, bacteremia, carbapenem-resistant Acinetobacter baumannii, colistin, neonates