What Type of Door Handle Has the Least Bacteria?
A superbug lurks within the National Institutes of Health Clinical Center in Bethesda, Maryland. The antibiotic-resistant Klebsiella pneumoniae arrived in August 2011 and has since claimed seven lives. The most recent was a young boy from Minnesota, who was already suffering from a genetic defect which had crippled his immune system.
With news of the pernicious bug in wide circulation, additional attention is being given to the need to stave off hospital-borne infections. A recent study published in PLoS ONE takes a look at one of the most common avenues of bacterial transmission: door handles.
Researchers from the United Kingdom observed six different door thresholds in close proximity to each other in a bustling urban hospital. Two of the doors were equipped with lever handles, while four featured flat rectangular push plates on one side, and long, vertical handlebars on the other. Movements through all the thresholds were monitored daily over a six-month period, twice a day at the same times, in 150-minute intervals. The door handles were thoroughly disinfected beforehand, and bacterial counts were taken after each observational period.
When analyzing the data, the researchers looked to see whether or not certain handle types were more likely to accumulate bacteria. They found that lever handles sported the highest ratio of bacteria contaminants per use (6.38), followed by pull handles (2.24), then push plates (1.2). They theorize that this difference may be because pull handles and levers require more hand contact to open the doors, leading to a greater concentration of bacteria on the handle.
The researchers warn that confounding variables in the study, such as room use, uncontrolled hygiene practices by staff, and the small number of testing locations hamper any wide-reaching conclusions. But considering that door handles are so widely used in hospitals (and everywhere for that matter), it would be wise to consider their design as a potential way to reduce hospital infections.
Automatic doors, where no touching is required, could be a potential solution. Additionally, copper door handles have been shown to be effective at suppressing bacterial growth.
Source: Wojgani H, Kehsa C, Cloutman-Green E, Gray C, Gant V, et al. (2012) Hospital Door Handle Design and Their Contamination with Bacteria: A Real Life Observational Study. Are We Pulling against Closed Doors? PLoS ONE 7(10): e40171. doi:10.1371/journal.pone.0040171