Rate of bacterial recolonization of the skin after preparation: four methods compared.

Fifteen volunteers lay supine for 3 hours in an empty operating theatre. Five rectangular areas were marked on the abdomen of each volunteer and a different antiseptic preparation was applied to four of the five areas. These were: 3 min painting with chlorhexidine in 70 per cent alcohol; 3 min painting with povidoneiodine in 70 percent alcohol; I min painting with 70 percent isopropyl alcohol and application of a plastic adhesive drape ('Opsite', Smith and Nephew Ltd); and I min painting with 70 percent isopropyl alcohol and application of a plastic adhesive drape containing slow-release iodophor ('Ioban drape' 3M Health Care). The fifth area was used as a control. Samples were taken from a different part of each area after 5, 30,60 and 180 min, using Rodac contact sampling plates containing oxoid columbia agar with 10 per cent horse blood, I per cent Tween 80, 0.3 per cent azolectin and 0.3 per cent sodium thiosulphate. After aerobic incubation the bacterial count on each plate was recorded.