Skin disinfection with a single-step 2% chlorhexidine swab is more effective than a two-step povidone-iodine method in preventing bacterial contamination of apheresis platelets

BACKGROUND: Skin commensal bacteria account for most septic reactions after apheresis platelet (PLT) transfusion. Consequently, we evaluated the effectiveness of two skin disinfection methods in preventing bacterial contamination of PLT collections. STUDY DESIGN AND METHODS: Three regional blood centers evaluated a one-step 2% chlorhexidine/70% isopropyl alcohol (2% CHX/IPA) skin disinfection method (trial group), while 32 blood centers (control group) continued to use a two-step povidone-iodine (P-I) method. Aerobic quality control bacterial culture results and adverse donor events were compared between April 1, 2009, and December 31, 2009. RESULTS: The rate of initial positive bacterial cultures was significantly lower in the trial regions compared to control regions in 2009 (143 vs. 321 per million: odds ratio [OR] 0.44, 95% confidence interval [CI] 0.23-0.86]). Trial regions also tended to have lower rates of both true-positive cultures (100 vs. 214 per million: OR 0.47, 95% CI 0.21-1.03) and false-positive (contamination) cultures (43 vs. 96 per million: OR 0.45, 95% CI 0.14-1.49). No differences were seen in the corresponding periods in 2007 and 2008 when all centers used P-I skin preparation. Allergic reactions were reported after 89 of 73,247 apheresis procedures (0.12%) in the trial regions representing a 16-fold increase (OR 15.9, 95% CI 9.9-25.6) compared to control regions. CONCLUSION: The 2% CHX/IPA single-step skin swabs are more effective in preventing bacterial contamination of apheresis PLT components than a two-step P-I skin disinfection method and may reduce the risk of septic transfusion reactions. Skin irritation and allergic reactions were more likely among donors in trial regions, but reactions were generally mild and self-limiting.