Single Positive Commensal Blood Culture in hospital setting is associated with higher mortality after hematopoietic stem cell transplantation

Abstract

BackgroundSingle positive staphylococcal blood culture in a hematopoietic stem cell transplantation (HSCT) recipient is generally regarded as contamination. Such a blood culture (BC) does not fill the criteria for Laboratory-Confirmed Bloodstream Infection (LCBI) and could be described as Single Positive Commensal Blood Culture. The aim of this retrospective cohort analysis was to determine the clinical significance of SPCBC in HSCT recipients. Methods206 patients transplanted between 2007 and 2013 were followed until January 2015. ResultsThe 100-day survival for patients without positive BC was 99.6% compared with 83.9% for LCBI and 82.8% for SPCBC (p=0.0036). The 5-year overall survival (5yOS) was 67.1% for patients without positive BC, 44.9% for LCBI, 34.0% for SPCBC (p<0.0001). The per-day risk of developing SPCBC was identical in autologous and allogenic transplantation. SPCBC remained a significant factor for reduced 5yOS after HSCT in the univariate analysis (HR 2.52, 1.26–5.02, p=0.0001) as well as in the multivariate analysis (HR 2.21, 1.26–3.87, p=0.006). SPCBC consisted solely of different Staphylococcus species with dominance of Staphylococcus epidermidis (64% of SPCBC). ConclusionTo our knowledge this is the first report that specifically shows that short- and long-term survival after HSCT is significantly lower in patients who experience an episode of SPCBC with Staphylococcus spp. during HSCT hospitalization.