SAN DIEGO – Use of antibiotics was cut by one-third among 3- to 5-year-olds attending child care centers that used enhanced hard surface disinfection practices in a multicenter randomized trial.
The intervention involved the use of commercially available wipes and sprays containing quaternary ammonium chloride compounds as well as a combined cleaner plus 1.9% sodium hypochlorite.
Dr. Charles P. Gerba
“Our intervention involved providing easier-to-use products that are more likely to provide an effective dose of the disinfectant, and the disinfection intervention appeared to reduce antibiotic use,” Charles P. Gerba, Ph.D., observed at the annual Interscience Conference on Antimicrobial Agents and Chemotherapy.
The 10-week study included 402 children at a dozen Arizona day care centers. Six centers were randomized to serve as controls, with the staff continuing to follow standard disinfection protocols recommended by the Arizona state health department: namely, a two-step process entailing the use of soapy water followed by bleach.
The other six centers were provided with the commercial hard surface disinfectants and instructed in using them effectively to kill germs. For example, the disinfecting wipes were to be used daily on refrigerator door handles and after every use of diaper-changing areas and high chairs. The one-step cleanser/dilute bleach product was to be applied daily to the sink, toilet, and countertops.
“These quat ammonium-containing wipes and sprays typically require 2-10 minutes of contact time in order to disinfect,” explained Dr. Gerba, professor of microbiology and environmental sciences at the University of Arizona, Tucson.
Hand-washing practices continued as usual throughout the study.
Every time a child missed school during the 10-week study, Dr. Gerba or a coinvestigator phoned the parents to learn if the child was sick, had sought medical attention, or was taking antibiotics.
The key finding: In a multivariate Poisson regression analysis, the use of antibiotics was 32% lower in the intervention arm than in controls.
Children attending the day care centers in the intervention arm also had fewer medical visits. Moreover, microbiologic sampling of hard surfaces at the participating centers documented that fewer antibiotic-resistant bacteria were present at the centers using enhanced disinfection practices.
Asked if he expects his study findings to result in a widespread change in cleaning practices at child care centers, Dr. Gerba noted that the commercially available enhanced disinfectant products are costlier than a bucket of soapy water and another bucket of dilute bleach.
“Child care centers are sensitive to cost,” he said. “Our current studies are examining the economic benefit of using products that are more convenient and contain the right doses for disinfection.”
He dismissed audience concerns that microbes might develop resistance to the disinfectants used in this study.
“In 120 years, no one has ever seen resistance to chlorine bleach by any microorganisms in continuous exposure. The same can be said for quat compounds. The literature shows that if they are used properly for disinfection, microorganisms don’t develop resistance because basically you’re using a stick of dynamite to kill a cockroach,” Dr. Gerba said.
The study was partially funded by a research grant provided by the Clorox Company to the University of Arizona, Tucson.