Comparison of disinfective power according to application order of 70% isopropyl alcohol and 10% povidone-iodine

Kim, Sang Su; Yu, Soo Bong; Kim, Joo Duck; Ryu, Sie Jeong

Abstract

BACKGROUND
Many disinfectants have been used clinically in both single and combination applications, but there have been few studies on disinfective power according to sterilization sequence when using a combination of disinfectants. The purpose of this study was to evaluate the disinfective power of a combination of 70% isopropyl alcohol and 10% povidone-iodine (PVP-I) according to sterilization sequence.
METHODS
Two hundred healthy volunteers were recruited. Subjects were disinfected with a combination of 70% isopropyl alcohol and 10% PVP-I on both forearms, in varying sequence. The AP group included disinfections on the left forearm with isopropyl alcohol first followed by 10% PVP-I, while the PA group included disinfections on the right forearm with same disinfectants in reverse order. Skin cultures were obtained using cotton swabs 3 min after application of each disinfectant, and then were inoculated on blood agar plates for bacterial culture. Cultures were incubated at 37degrees C under aerobic conditions for 48 hours.
RESULTS
There was no significant difference in the number of positive cultures after the 1st disinfection (AP, 45; PA, 36, P = 0.262) or the 2nd disinfection (AP, 6; PA, 13, P = 0.157), suggesting that there is no relationship between disinfective power and the sequence of the disinfectants used. The number of positive cultures significantly decreased after the 2nd disinfection (P < 0.01), however.
CONCLUSIONS
There was no significant difference in disinfective power according to sterilization sequence with 70% isopropyl alcohol and 10% PVP-I in healthy volunteers. The combination of 70% isopropyl alcohol and 10% PVP-I was more effective than disinfection with a single agent regardless of sterilization sequence.