Dry hot air: is it a reliable method of disinfection for urological endoscopes? Preliminary study

To evaluate dry hot air effect as a reliable method of disinfection of urological endoscopes.

Two groups of urological endoscopic instruments (2 cystoscopic sheaths, 2 bridges, and 2 working elements of resectoscope and urethrotome for each group), after being sterilized by full immersion in 2% glutaraldehyde solution for 10 hours, were contaminated by immersion in suspensions of Staphylococcus saprophyticus (3 x 10(3) CFU/mL), Escherichia coli (28 x 10(2) CFU/mL), and Candida albicans (27 x 10(2) CFU/mL). Group I was exposed to disinfection by full immersion in 2% glutaraldehyde solution for 20 minutes. Group II was exposed to dry hot air obtained by using a hair dryer for 3 minutes. The surfaces and lumens of the instruments of both groups were washed with specific volumes of saline. The surface and luminal specimens were collected separately and used for culture on different media specific for these organisms. Colony-forming units were estimated.

In group I, the cultures isolated from the instrument surface washes were negative but those isolated from the luminal injected saline were all positive for S. saprophyticus (60 CFU/mL), E. coli (50 CFU/mL), and C. albicans (50 CFU/mL). In group II, the cultures isolated from both the instrument surface and luminal saline washes were negative for all 3 above-mentioned microorganisms.

Hot dry air by using a hair dryer is an inexpensive, rapid, easy, easily available, and effective method of disinfection compared with glutaraldehyde solution.