In vitro-in vivo sequence studies as a method of selecting the most  efficacious alcohol-based solution for hygienic hand disinfection.
The use of alcohol-based hand rubs serves to reduce hospital-acquired infections. Many products of this type are now on offer and it is essential to know how to rank their efficacy. A sequence of tests is proposed here to compare any given new alcohol-based solution against the reference solution (60% 2-isopropyl-alcohol) with 30 s of contact time: (i) in vitro (with pig skin as carrier) testing of >30 species of microorganism; (ii) in vitro assessment of residual efficacy (after 30 min of drying); (iii) in vivo study of transient microbiota (modification of the EN 1500 standard procedure) using four ATCC strains; (iv) in vivo study of resident hand microbiota. After performing the in vitro evaluation of seven alcohol-based hand rubs, the two most efficacious (chlorhexidine-quac-alcohol and mecetronium- alcohol) were chosen and studied, comparatively with the reference solution (60% isopropyl alcohol), in vitro (for chemical sustainability on the skin) and in vivo (against transient and resident microbiota). Chlorhexidine-quac-alcohol proved to be significantly superior to mecetronium-alcohol or the reference solution in all tests, except against resident microbiota for which the improvement was not statistically significant.
Herruzo
R
R
Department of Preventive Medicine, Autonomous University of Madrid, Spain. rafael.herruzo@uam.es <rafael.herruzo@uam.es>
Vizcaino
M J
MJ
Herruzo
I
I
D019840:2-Propanol / Q000008:administration & dosage*; D000438:Alcohols; D000704:Analysis of Variance; D000818:Animals; D000891:Anti-Infective Agents, Local / Q000008:administration & dosage*; D001419:Bacteria / Q000187:drug effects*; D002710:Chlorhexidine / Q000008:administration & dosage; D006235:Hand Disinfection / Q000379:methods*; D006801:Humans; D000644:Quaternary Ammonium Compounds / Q000008:administration & dosage; D012867:Skin / Q000382:microbiology; D012996:Solutions; D013552:Swine
D000438:Alcohols; D000891:Anti-Infective Agents, Local; D000644:Quaternary Ammonium Compounds; D012996:Solutions; C522448:ethylhexadecyldimethylammonium; D019840:2-Propanol; D002710:Chlorhexidine