[Can the DGHM test for the surgical hand disinfection be used to detect residual effects?]

It is investigated if the log reductions measured by the DGHM test for examination and evaluation of disinfecting procedures for the surgical hand wash, i.e. the short and long term values RFreference, 0h, RFreference, 3h, RFpreparation, 0h and RFpreparation, 3h can be used to detect residual effects (a remanent action) of the tested preparation. To do this the differences delta RF = RF0h-RF3h of reference and tested preparation have been formed which are a measure for the bacterial regeneration rate. A remanence index RI = magnitude of delta RFreference/magnitude of delta RFpreparation has been specified, which, in case RI > 1 indicates a residual effect of the test preparation in relation to the reference. The evaluation of 21 testing protocols is showing that the calculated remanence indexes are far away from any significance. This is attributed on the one hand to the great standard deviations of the log reductions and on the other hand to virtually only small residual effects of the tested preparations.