Mar 31, 2011 (CIDRAP News) Electronic, non-touch faucets are being used in many healthcare facilities to save water and improve hand hygiene, but the faucets may actually increase the risk of infections for some patients, according to research findings released by the Society for Healthcare Epidemiology of America (SHEA) today.
Researchers at the Johns Hopkins University School of Medicine tested water from electronic and manual faucets in two hospital wards and found that water from the electronic faucets was more often contaminated with Legionella species and had a higher overall bacterial load.
The findings were outlined in a news briefing last week and in a news release from SHEA today. The study is scheduled to be presented in more detail at SHEA's annual meeting on Apr 3.
Over 6 weeks in December 2008 and January 2009, Emily Sydnor, MD, and colleagues cultured water samples from 20 manual and 20 electronic faucets, all of which received water from the same source. Sydnor is an infectious disease fellow at Johns Hopkins.
Cultures from 50% of the electronic-faucet samples grew Legionella, versus only 15% of cultures from the manual faucets, Sydnor said. She also found that 26% of electronic-faucet samples had significant growth on heterotrophic plate count (HPC) cultures, an indicator of the overall bacterial load, compared with 13% for the manual faucet samples. The latter difference was not statistically significant, but Sydnor said it was worth noting.
Further, the difference between the two kinds of faucets persisted after the water system was flushed with chlorine dioxide. In follow-up testing, 29% of electronic-faucet samples still showed contamination, compared with 7% of the manual-faucet samples.
The findings led to a Johns Hopkins decision to replace electronic faucets in clinical areas with the manual kind and to use manual faucets in the clinical areas of a hospital building now under construction, Sydnor said.
"We'd suggest that infection control teams evaluate electronic faucets . . . and consider removal in at-risk patient areas," she commented at the briefing.
However, she said the findings do not mean using electronic faucets is risky for the general public. The faucets will still be used at John Hopkins in restrooms intended for the public.
"The levels of bacterial growth in the electronic faucets, particularly the Legionella species, were of concern because they were beyond the tolerable thresholds determined by the hospital," she commented in the release. "Exposure to Legionella species is dangerous for chronically ill or immune compromised patients because it may cause pneumonia in these vulnerable patients. The levels we found of both Legionella species and bacterial burden on HPC were still within the level that is well tolerated by healthy individuals."
The suspected reason for the increased contamination in water from the electronic faucets is that they have more parts that can trap bacteria, Sydnor said. She noted that the study involved just one brand of electronic faucet.
"There are five extra parts that you wouldn't have in a manual faucet," she said at the news briefing. As part of the study, two of the faucets were dismantled and the individual parts were tested. "Every single part grew both Legionella and high counts of overall bacterial growth," she said.
Sydnor noted that a few previous studies have shown increased bacterial contamination in electronic faucets, and it was the combination of previous evidence and the new findings that prompted Johns Hopkins to change the equipment in clinical areas.
Among the previous studies is one published in Intensive Care Medicine in 2006. Investigators tested 92 water samples from electronic faucets and 135 from manual faucets in the hematology and intensive care units of two large hospitals in France. They found that 39% of the electronic-faucet samples and just 1% of the manual faucet samples were contaminated with Pseudomonas aeruginosa, a common hospital pathogen. As in the Johns Hopkins study, the contamination remained after a chlorine flush of the system.
In an earlier study, researchers at a hospital in Grand Forks, N.D., tested water from two brands of electronic faucet and one type of manual faucet. They found that water from one of the two types of electronic faucets had significantly higher overall bacterial counts than water from the other two faucet types, according to a report published in Infection Control and Hospital Epidemiology (ICHE) in 2001.
Mar 31 SHEA press release
2006 Intensive Care Med abstract
2001 ICHE abstract