Attributable Mortality of Imipenem-Resistant Nosocomial Acinetobacter baumannii Bloodstream Infection
Silom Jamulitrat MD*, Pranee Arunpan RN**, Parichart Phainuphong RN**
Affiliation : * Department of Community Medicine, Faculty of Medicine, Prince of Songkla University, Hat Yai, Songkhla, Thailand ** Infection Control Unit, Songklanagarind Hospital, Songkhla, Thailand
Background : Uncertainty remains concerning the mortality attributable to infections caused by imipenem-
resistant acinetobacter baumannii (IRAB). The authors have sought to examine the impact of this resistance
on patient mortality.
Objective : To evaluate the effects of imipenem resistance on the mortality of patients with Acinetobacter
baumannii bloodstream infection.
Material and Method: A cohort study was conducted to compare the survival rates between patients with
IRAB and imipenem-susceptible A. baumannii (ISAB) bacteremia.
Results : The present study shows 35 patients (52.2%) in an IRAB group died in hospital compared to 26
patients (19.9%) in an ISAB group (p < 0.001). Multivariate analysis using Cox’s proportional hazard model
for controlling the confounding effects due to the severity of underlying diseases, inappropriate antibiotic
treatment, and primary source of bacteremia show no statistically significant difference in mortality rates
between the two groups.
Conclusion : The observed higher mortality rate among patients with an IRAB bloodstream infection may not
be attributable to imipenem resistance but may in some part be due to a more severe illness, inappropriate
antimicrobial therapy, and primary source of infection.
Keywords : Acinetobacter baumannii, Imipenem, Carbapenems, Drug resistance, Cross infection, Bacteremia, Epidemic, Disease outbreaks, Hospital mortality, Virulence factors
