THE EFFECT OF SKIN DISINFECTION MATERIALS ON REDUCING BLOOD CULTURE CONTAMINATION

Contaminated blood cultures may cause results to be misinterpreted, cr eate unnecessary work for the laboratory, and increase costs. Disinfec tion of the venipuncture site is considered to be necessary for preven ting contamination, although there is little information about the eff ectiveness of using different disinfection materials. The use of 70% i sopropyl pads and povidone iodine saturated swabs (conventional method ) was compared with the use of a 70% isopropyl/10% acetone scrub and p ovidone iodine dispenser (PREP method) for skin disinfection. Blood cu lture ''kits'' were prepared-bags containing collection tubes, instruc tions, and either conventional or PREP materials and were distributed randomly. The contents were concealed by a cover to prevent the user f rom selecting a specific type of decontamination kit. The kits were id entified in the laboratory by color-coded labels on the collection tub es. Among 1,546 specimens evaluated, the contamination rate observed w ith conventional disinfection was significantly higher (4.6%; N = 763) than with PREP materials (2.2%; N = 783, P = 0.011) and was equivalen t to the preceding 6-month contamination rate (4.7%). The lower contam ination rate may be associated with greater effectiveness of a scrub o r isopropyl/acetone solution, or both. Decontamination materials may h ave a significant impact on reducing blood culture contaminants from s kin flora.