An In Vitro evaluation of disinfection protocols used for needleless connectors of central venous catheters

A repeatable and sensitive method to evaluate the effect of three antiseptics and two disinfection techniques on viable micro‐organisms on luer‐activated catheter needleless connectors ( NC s) was developed. NC s were inoculated with S taphylococcus epidermidis or K lebsiella pneumoniae and disinfected with 3·15% chlorhexidine gluconate + 70% isopropanol ( CGI ), 70% isopropanol ( IPA ) or 10% PVP povidone‐iodine ( PI ) antiseptic pads using: (i) scrubbing the NC septum and threaded external surfaces or (ii) wiping only the surface of the septum. Treatments were also evaluated against NC s pretreated with human serum and exposed for 18 h to S taph. epidermidis prior to testing. Viable cells were quantified by plate count. The method for inoculation and recovery of luminal micro‐organisms was repeatable ( SD , 0·31; n  = 28). IPA disinfection provided an approximate 3 log 10   CFU reduction; CGI and PI provided 3–4 log 10 reductions. PI and CGI were more effective than IPA ( P  < 0·05), but differences between CGI and PI were not significant for either disinfection method. IPA , but not CGI and PI was also less effective ( P  < 0·05) against NC s inoculated with Kl. pneumoniae than S taph. epidermidis . Pretreatment with serum and prolonged S taph. epidermidis inoculation removed the advantage seen with CGI and PI ; log 10 reductions were 1·80, 1·73 and 2·50 for CGI , PI and IPA , respectively. PI or CGI may be more effective than IPA for NC disinfection but effectiveness may be reduced on NC s contaminated with blood or serum. Significance and Impact of the Study sensitive and repeatable protocol was developed to evaluate antiseptics for disinfecting catheter needleless connectors ( NC s). P ovidone‐iodine ( PI ) and chlorhexidine gluconate plus isopropanol ( CGI ) were more effective than isopropanol ( IPA ) for reducing S taphylococcus epidermidis contamination of NC s. The effectiveness of PI and CGI was reduced on NC s pre‐exposed to human serum and prolonged bacterial inoculation. IPA was also less effective against NC s contaminated with K lebsiella pneumoniae .