Epidemiological risk factors for nosocomial bloodstream infections: A four-year retrospective study in China.

PURPOSE: The objective of this study was to retrospectively research the clinical characteristics, pathogen distribution, prognosis of nosocomial bloodstream infection (nBSI), and the associated risk factors for nBSI. MATERIALS AND METHODS: The clinical and microbiological data of patients with nBSI were retrospectively studied. Patients were treated at the First Affiliated Hospital of Zhejiang Chinese Medical University (Zhejiang Hangzhou, China) between January 2013 and December 2016. RESULTS: Our study spanned a four-year period and included 704 episodes of nBSI. The incidence rate was 4.11 per 1000 admissions. Of these cases, 96.7% were monomicrobial: gram-negative bacteria (56.4%), gram-positive bacteria (33.4%), and fungal (7%). Of all the Escherichia coli isolates, 41.5% were extended-spectrum ß-lactamase-producing (ESBL)-positive. Of the Klebsiella pneumoniae isolates, 50.9% were resistant to imipenem. Of the Staphylococcus aureus isolates, 42.1% were methicillin-resistant. The overall 28-day mortality rate in all patients with nBSI was 24.4%. Parenteral nutrition (PN) and sequential organ failure assessment (SOFA) scores (≥5) were closely related to the 28-day mortality rate of nBSI, while removal of venous catheters and appropriate empirical therapy were protective factors of 28-day mortality. CONCLUSIONS: Gram-negative bacteria predominantly developed in nBSI. Timely removal of venous catheters (catheter retention time ≥ 7 days) and implementation of appropriate empirical therapy improved the nBSI outcomes.