Bactericidal and virucidal activity of ethanol and povidone-iodine

Ethanol and povidone-iodine (PVP-I) are important microbicides that inactivate bacteria and viruses. The present study provides a review of literature data on the concentration-dependent bactericidal and virucidal activity of ethanol and PVP-I in vitro. A systematic search was performed using the meta-database for biomedicine PubMed. Eventually, 74 studies with original data on the reduction of bacterial and viral infectivity using in vitro tests were analyzed. A safe bactericidal effect of ethanol can be expected at concentrations between 60% and 85%, and the exposure times vary between ≤0.5 and ≥5 min. Within an exposure of up to 5 min, 80%-90% ethanol also exerts virucidal/low-level activity, which includes its action against enveloped viruses plus adeno-, noro-, and rotaviruses. For PVP-I, the best bactericidal and virucidal/high-level effect is present at a concentration range of approx. 0.08%-0.9% depending on the free iodine concentration. The maximum exposure times are 5 min for bacteria and 60 min for viruses. The available data may help optimize the significant inactivation of bacteria and viruses in various areas. However, as the conditions in application practice can vary, concrete recommendations for the application can only be derived to a limited extent.