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.

Keywords: Nosocomial bloodstream infection, Outcome, Factors influencing prognosis