Short- and
long-term effects of handwashing with antimicrobial or plain soap in
the community.
by
Larson E, Aiello A, Lee LV, Della-Latta P, Gomez-Duarte C, Lin S.
Schools of Nursing and Public Health,
Columbia University, New York, NY 10032, USA. J Community Health. 2003 Apr;28(2):139-50.
ABSTRACT
Little is known about effects of public use of
antimicrobial handwashing soap. A double-blinded, randomized clinical
trial of hands of primary caretakers in 238 inner city households was
conducted in which effects of plain or antimicrobial (containing 0.2%
triclosan) handwashing soap on bacterial counts of the hands were
compared before and after a single wash and before and after
handwashing following a year of product use. The randomly assigned
product was provided without cost to each household during monthly home
visits, and compliance with product use was monitored. Households were
contacted by telephone weekly and with a home visit monthly for 11
months. Hand cultures were obtained before and after handwashing at
baseline and after 11 months, using a modified glove juice technique.
Overall, there were no significant differences in pre-to-post
handwashing counts at baseline (p = 0.41), but by the end of one year,
post-wash counts were significantly lower than pre-wash (p = 0.000) for
those using either antimicrobial or plain soap. There were no
significant differences in mean log counts either before or after
handwashing between those using the antimicrobial or plain soap at
baseline or after a year of use (all p values > 0.28). For the
group
using antimicrobial soap, higher counts were observed post-handwashing
in 31.3% of paired samples at baseline and 26.7% after one year (p =
0.03). A single handwash had minimal effect on quantity of hand flora,
but there were significant effects over time, regardless of whether
antimicrobial or plain soap was used. In the absence of more definitive
evidence, the risk-benefit ratio argues in favor of targeted rather
than ubiquitous, general household use of antimicrobial soap.