Nosocomial bloodstream infection in Songklanagarind Hospital: outcome and factors influencing prognosis.

OBJECTIVE To determine epidemiology, microbiology, outcome, and factor influencing mortality in nosocomial bloodstream infection in Songklanagarind Hospital. MATERIAL AND METHOD Retrospective study in adult patients who were hospitalized at Songklanagarind Hospital with positive blood culture after 48 hours of admission was conducted. The present study duration was between 1 August and 30 November 2008. RESULTS There were 138 episodes of nosocomial blood stream infection in 117 patients, the prevalence of 11.6/1,000 admissions. The mean age of patients was 54.8 years (range 12 to 88 years) and males comprised of 60.9%. Hematologic malignancy was the most common underlying condition of the patients (27.5%) while 30.4% of patients had no underlying disease. The three common primary infections were lower respiratory tract (13.9%), urinary tract (12.4%) and skin and soft tissue (6.5%), whereas the unknown site of infection had accounted for 80 episodes (62.0%). The leading pathogens of nosocomial bacteremia were E. coli 17.4%, S. aureus 15.2%, K. pneumoniae 12.3% and P. aeruginosa 10.3%. Vanocomycin was dominantly sensitive to gram positive cocci, while about half (52.4%) of S. aureus had methicillin resistance. The variety of resistance had encountered for example P. aeruginosa (7.1%) to imipenem and majority of A. baumannii to aminoglycosides, fluoroquinolones and carbapenems. Overall mortality was 28.3% but mortality due directly to bacteremia was 13.8%. Univariate and multivariate analyses showed liver cirrhosis and lower respiratory tract infection to be associated with increased mortality. CONCLUSION The prevalence of nosocomial blood stream infection had slightly sideway down, while the mortality was stable, compared with several reports in the last two decades. The gram negative bacteria had a high proportion of antibiotic resistance.