A review of methods for the evaluation of handwashing efficacy

Handwashing is relied upon in numerous fields as a primary means to prevent transmission of harmful pathogens. While handwashing is a key step in disease prevention, the factors controlling its effectiveness are not always well understood, and there are extensive variations in the methodology used to assess each of these factors. This review summarizes the various factors that can impact handwashing effectiveness as well as the methods and results of studies evaluating each of these factors related to handwashing. Numerous methods are available to inoculate hands as well as to recover microorganisms from hands, and for a given method, experimental variables can be changed between researchers. These variations amongst methods as well as variations in reporting experimental results can make it difficult to compare studies as well as challenging to accurately interpret the results between studies. Standardization of methods and reporting requirements are necessary to allow for comparison of studies so that more accurate conclusions about the handwashing process can be made. Therefore, the need for 1) the development of more standardized handwashing test methods and 2) the formation of guidelines on the minimal information required for publication of handwashing experiments are considered and discussed. (C) 2015 Elsevier Ltd. All rights reserved.