Risk factors and clinical outcomes of multidrug-resistant Acinetobacter baumannii bacteremia at a university hospital in Thailand

Multidrug-resistant (MDR) Acinetobacter baumannii has become a major cause of hospital-acquired infection worldwide. There are few papers regarding this particular subject. Our aim was to assess the incidence of bacteremia due to MDR Acinetobacter baumannii, factors associated with the infection, and clinical outcomes. We studied 49 cases of A. baumannii bacteremia in adult patients admitted to a university hospital in Northeast Thailand between 2005 and 2007. The incidence of MDR A. baumannii bacteremia was 3.6 episodes per 10,000 hospital admissions. Significantly independent factors associated with MDR A. baumannii bacteremia were previous: 1) ICU admission odds ratio (OR) 10.01; 95% confidence interval (CI) 1.39-72.20]; 2) use of beta-lactam/beta-lactamase inhibitor antibiotics (OR 8.06; 95%CI 1.39-46.64); and 3) use of a carbapenem antibiotics (OR 11.40; 95%CI 1.44-89.98). The overall mortality rate was significantly higher in the MDR group than in the susceptible group (91.7% vs 48%, respectively) (p=0.001). The significantly independent factors related to mortality were: 1) APACHE II score (OR 1.25; 95%CI 1.03-1.52) and 2) secondary bacteremia (OR 14.86; 95%CI 1.37-161.90). This study revealed the significantly independent factors associated with MDR A. baumannii bacteremia were prior ICU admission and prior use of broad spectrum antibiotics. This infection has a high mortality rate. Emphasis needs to be on prevention, strict application of infection control and appropriate use of antibiotics.