Sensing Potential Problems with Electronic Eye Faucets

The public bathroom scene is changing.  Increasingly, manual faucets and soap dispensers are being replaced by hands-free electronic eye faucets that conserve water and need only sense a pair of hands to start running water of a perfect temperature. This is a positive development because those who wash their hands don’t have to touch the faucet handles, or the soap dispenser.  Even many paper towel dispensers now detect our hands and automatically provide paper.  Sensors have become our friend and ally in preventing infections.

So, you’ve washed your hands using this new technology, but how clean are they?

According to a March 31 press release, although hands-free electronic eye faucets conserve water, a seven-week study at Johns Hopkins hospital shows that there may be an unintended consequence to their use:  Water dispensed from electronic eye faucets is more likely than manual faucets to be contaminated with a common hazardous bacterium.  Researchers compared water samples from 20 electronic-eye faucets and 20 manual faucets in or near patient care areas at Johns Hopkins; they found the waterborne bacteria Legionella growing in 50 percent of water samples from electronic-eye faucets, whereas the same bacteria was found in only 15 percent of samples from manual faucets.  Additionally, weekly water cultures showed half the amount of bacterial growth of any kind in manual faucets compared to electronic ones.

The researchers believe that standard hospital disinfection methods that complement normal public utility treatment, might not work well on the “complex valve components” of electronic faucets.  Disassembling some of the faucets, the team found Legionella and other bacteria on all of the main component valves and other parts, very few of which exist in manual faucets.

Emily Sydnor, M.D. a fellow in infectious diseases at Johns Hopkins and the lead study investigator, stated in an article in Infection Control Today that “Legionella bacteria, commonly found in water supplied from public utilities, rarely cause illness in people with healthy immune systems, but pose a real risk of infection in hospital patients whose immune systems are weakened from cancer chemotherapy, anti-rejection drugs after organ transplant, or from diseases such as HIV/AIDS”.

As the result of the study, the Johns Hopkins hospital leadership made the decision to remove the 20 electronic-eye faucets from its patient care area and replace them with standard manual ones. The same is being done a building currently under construction and set to open in 2012.

In the following months, the Johns Hopkins researchers are planning to work with the manufacturers of electronic eye faucets to correct the faucet design flaw.

These study results are interesting, but also raise many questions.  It would be good to know, for example, why Legionella proliferates in electronic eye faucets—is it because the preferred water temperature for hand washing is similar to the optimal temperature range for proliferation of Legionella? Is it due to a material or substance used in manufacturing the faucets that fosters Legionella’s growth?  Further, is it possible that hand washing contributes to inhalation of water droplets or vapor, the primary route of Legionella exposure? Perhaps the researchers will consider an epidemiological study to see if reverting to traditional faucets results in any reduction in hospital acquired legionellosis.

Barbara M. Soule, R.N. MPA, CIC, is an Infection Preventionist and a member of the Water Quality & Health Council.