Blood cultures (BC) remain the gold standard for diagnosis of bacteraemia in infants and children, despite the incredible advances in the molecular diagnosis of bacteraemia [1]. One of the most important obstacles that decreases the diagnostic value of blood culture is contamination and contamination of BC results in prolonged hospitalisation, inappropriate antimicrobial prescription and unnecessary investigations resulting in increase in healthcare costs [2]. For instance, the average BC contamination rate in hospitals in the United States is 2.9 %, while there were variety of reports of contamination rate ranging from 0.6 to 12.5 % in different population [3,4]. Patients who have contaminants isolated from blood culture experience significant clinical consequences, including the need for follow-up care and repeat blood cultures. In addition, when present, the contamination in the BC might cause unnecessary antibiotic usage and increased healthcare costs up to $8000 per contamination event [3].

Since skin organisms represent the most common blood culture contaminants, the appropriate use of skin antiseptics is among the most important methods to minimize contamination due to insufficient disinfection [1,5,6]. While the use of aqueous povidone-iodine is widely used at many centers especially for younger infants, chlorhexidine with or without alcohol has been preferred over povidone-iodine. Chlorhexidine was reported to cause a dramatic reduction in skin flora, has residual activity for hours, and requires less drying time makes it a good candidate for disinfection for BC collection [7]. Previous studies are mostly adult studies and reported alcoholic chlorhexidine was effective at lowering the blood culture contamination rates compared to povidone-iodine [[8], [9], [10]].

Although these studies have shown the superiority of chlorhexidine, there are few data coming on the use of this antiseptic as the standard of care for BC in the paediatric hospitals [1,11]. Previous experience, using chlorhexidine instead of povidone-iodine in addition to other bundle steps were reported to be effective in reducing central line–associated bloodstream infections at children [12,13] and the Centers for Disease Control and Prevention (CDC) recommends the use of chlorhexidine for central venous catheter placement for children as well as adults [14]. A newer product made of 2 % chlorhexidine and 70 % isopropyl alcohol (BD Chloraprep™, Becton, Dickinson & Company (BD), Franklin Lakes, NJ, USA) requires a 15-s drying time and is colourless, making it an attractive candidate for improved clinical effectiveness in the central venous catheter bundles, while use of BD Chloraprep™ in the field of disinfection before BC sampling is a new promising issue [15].

We have conducted a prospective, randomized trial directly comparing the BC contamination rates between two group of patients in which using a tincture of iodine plus alcohol skin-preparation process with the contamination rate for using the “2 % chlorhexidine with 70 % isopropyl alcohol skin-preparation process in children.