Background:
Bloodstream infection is one of the important causes of mortality, and morbidity in pediatric patients with hemato-oncologic disease. The purpose of this study was to identify the risk factors related to mortality in patients who suffered from a bloodstream infection.

Methods: We retrospectively reviewed and analyzed the medical records of 133 pediatric patients with hemato-oncologic diseases who had episodes of bloodstream infection documented at Asan Medical Center from June 2002 through May 2005.
Results: A total of 288 pathogens were isolated, and there were 17 episodes of polymicrobial infections. Among the episodes of bloodstream infection, 93.4% were caused by bacteria of which 60.1% were gram-positive bacteria, and 33.3% were gram-negative bacteria. Fungal infections accounted for 6.6% of the infections. The main pathogens included Staphylococcus epidermidis (31.3%), Pseudomonas aeruginosa (8.3%), and Klebsiella pneumoniae (7.3%). Gram-positive organisms were isolated more frequently than gram-negative organisms, and non-albicans Candida species were documented more frequently than C. albicans in our study. Infection related mortality was 8.3% (11 of 133 patients). The pulmonary infiltration on chest X-ray (CXR) (P=0.001), and a low absolute neutrophil count (≤500/ՌL) (P=0.017) at the time of blood culture were significantly associated with mortality. Gram-negative bacterial infection (especially with Stenotrophomonas maltophilia) and fungal infection often progressed to the septic shock or death.
Conclusion: This study revealed that the presence of pulmonary infiltration on a CXR, neutropenia (≤500/ՌL), and gram-negative bacterial infection might be important risk factors of mortality in pediatric patients with hemato-oncologic diseases necessitating more aggressive and vigilant supportive care.

Keywords: Bloodstream infection, Childhood cancer, Risk factors, Mortality