Washington: Liquid soap can become contaminated and washing hands with such contaminated soap from bulk refillable dispensers can leave you with deadly bugs on your hands -- some of which cause cholera and bacterial meningitis.
"Hand washing with soap and water is a universally accepted practice for reducing the transmission of potentially pathogenic microorganisms," says Carrie Zapka from GOJO Industries in Akron, Ohio, who led the study.
"However, liquid soap can become contaminated with bacteria and poses a recognized health risk in health care settings," adds Zapka, whose study also included scientists from BioScience Labs in Montana and the University of Arizona, Tucson.
Bulk-soap-refillable dispensers, common to public restrooms, are prone to contamination and several outbreaks linked to the use of contaminated soap have already been reported, according to the journal Applied and Environmental Microbiology.
Zapka and her colleagues investigated the health risk associated with the use of bulk-soap-refillable dispensers in a community setting, according to an Arizona statement.
They found an elementary school where all 14 of the soap dispensers were already contaminated and asked students and staff to wash their hands, measuring bacteria levels before and after handwashing.
They found that Gram-negative bacteria (which can trigger venereal disease and bacterial meningitis, besides cholera and bubonic plague), on the hands of students and staff increased 26-fold after washing with the contaminated soap.
"This is the first study to quantitatively demonstrate that washing hands with contaminated liquid soap actually increases the number of Gram-negative bacteria on hands.
"Furthermore, the results directly demonstrate that bacteria from contaminated hands can be transferred to secondary surfaces," says Zapka.