Hands-free dryers in Legionella bacteria claim
Legionella found in 50% of water samples from 20 hands-free faucets
A US hospital is replacing all hands-free faucets with manual models after a report found they contain more Legionella bacteria than those in conventional fixtures.
Although the reasons for the difference are unclear, researchers suspect the complex valve components of the newer faucets offer more surface area and hiding places for bacteria, which remain present after standard hospital water disinfection methods. Conventional faucets, on the other hand, have few internal parts.
According to Gizmag design magazine, The Johns Hopkins Hospital in Baltimore will work with manufacturers of the hands-free faucets to devise new ways of building them so they can be thoroughly cleaned.
“The hands-free faucets use a sensor to detect when a user's hands are present, at which point the water will automatically come on for a preset amount of time,” a spokesman said.
“Given that the whole process involves no touching of anything, it would appear to be more hygienic than a system in which multiple users touch hot and cold water handles with their unwashed hands. Johns Hopkins and other US hospitals obviously thought so, and proceeded to introduce the faucets in patient care and public areas over a decade ago.”
When Johns Hopkins staff were testing how often their water system needed to be flushed, they were surprised to discover Legionella growing in 50% of the cultured water samples from 20 hands-free faucets, compared to 15% in samples from 20 manual faucets in the same areas.
While Legionella poses little risk to healthy individuals, it can cause serious infections in people with weak immune systems.
The water from the traditional faucets was also found to contain just half the amount of other types of bacteria.
Three years ago, A study by the University of Westminster, in London, said ‘hygenic’ warm air hand dryers found in public washrooms left users with more bacteria on their hands than if they used paper towels.