Johns Hopkins researchers led by Emily Sydnor took a closer look at the hands-free faucets in hospitals and didn’t like what they found. The automatic faucets were up to three times as likely to be contaminated with Legionella bacteria as manual faucets.
This is counterintuitive to say the least. After all, the whole point of the hands-free faucets was to prevent contamination. The researchers themselves are puzzled as to why the electronic-eye fixtures, which have been in hospitals for over a decade, are so problematic. One possible reason may be that the hands-free faucets have more complicated valve and electronic components that cannot be effectively disinfected. Many hospitals treat their water supply specifically to reduce the levels of Legionella and other harmful pathogens. Those methods don’t appear to work on the electronic faucets, which can apparently harbor harmful levels of bacteria.
The researchers have contacted the faucet manufacturers to see if modifications can be made to allow the hands-free devices to be more thoroughly sterilized. In the meantime, Johns Hopkins Hospital is replacing its automatic faucets with manual ones. Unfortunately, this means the hospital will have to go back to using four times as much water for hand washing.
By the way, Sydnor does not think the general public has anything to fear from non-touch faucets in public venues:
The levels of bacterial growth in the electronic faucets, particularly the Legionella spp., were of concern because they were beyond the tolerable thresholds determined by the hospital. Exposure to Legionella spp. is dangerous for chronically ill or immune compromised patients because it may cause pneumonia in these vulnerable patients. The levels we found of Legionella spp. were still within the level that is well tolerated by healthy individuals.