Objective To assess the value of serum procalcitonin(PCT)in differential diagnosis of blood stream infection and contamination due to coagulase-negative staphylococci(CNS). Methods A retrospective analysis was conducted in clinical data of 128 sick children with positive CNS blood cultured in 2014.According to diagnostic criteria for bloodstream infections,the sick children were divided into blood-flow-infection group(n=62)and blood-pollution group(n=66).Serum PCT and other laboratory indexes were compared ...