Studies on the use of povidone-iodine with the 'hygienic hand disinfection' test

The DGHM test for hygienic hand disinfection is based on that of Rotter et al. (1980), and compares the ability of a test agent with 60% isopropanol to reduce Escherichia coli counts on artificially contaminated fingers using 15 volunteers. The test was performed seven times-three with 10% povidone-iodine (PVP-I) scrub, three with 10% PVP-I solution and one with 5% PVP-I solution. Initial tests with PVP-I scrub ('Betadine') gave comparable results with the iso-propanol, but the latter gave an activity below that normally expected, and specified in the Austrian standard (but not in the DGHM test). A repeat test with greater attention to detail gave similar activity with the scrub, but markedly greater activity from the iso-propanol so that the PVP-I scrub failed the test. Subsequent tests with four aqueous PVP-I solutions showed that all passed the tests with activity marginally greater than that of iso-propanol. Interestingly enough, two German formulations of PVP-I solution showed almost identical activity.