New Haven, Connecticut – Singing “Happy Birthday”? Recite the ABC? count 20 seconds? What is the best way to ensure handwashing effectiveness?
Maintaining good hand hygiene practices remains key to preventing the spread of pathogens in healthcare settings and beyond. However, hand hygiene habits have proven resistant to change among healthcare workers, patients and the general public alike.
Interventions to improve hand hygiene among healthcare workers included increasing the now ubiquitous presence of alcohol-based hand sanitizer dispensers, accompanied by signage and training, addressing organizational culture, and establishing accountability. Meanwhile, methods for assessing ongoing hand hygiene techniques in healthcare remain limited, and critics argue that a focus on compliance rather than quality misses the point and does not serve the ultimate goal of improving patient care by removing pathogens.
Now, a new paper published in the American Journal of Infection Control reports on a pilot study of an innovative new method of detecting unwashed stains on hands by using a handheld thermal imaging camera connected to an iPhone. Authors John M. Boyce, MD, of M Boyce Consulting, and Richard A. Martinello, MD, of Yale School of Medicine, describe the use of a forward-looking infrared thermal imaging (FLIR) camera to assess hand hygiene technique among 12 staff members who volunteered to participate in the study at the Department of Infection Prevention at Yale New Haven Hospital, Connecticut.
The technique is based on the observation that the application of alcohol-based hand sanitizers causes a temporary drop in skin temperature due to evaporation. Researchers placed the thermal imaging camera on a tripod to standardize images and used their smartphone app to tweak the color palette of the resulting images. By observing the skin temperature on all hands before and after applying alcohol-based hand sanitizer, the researchers attempted to assess the quality of hand hygiene practices among the 12 volunteers.
Thermal imaging enabled non-invasive but precise temperature measurement at three predefined points on the user’s dominant hand (metacarpus, tip of third finger, tip of thumb) at four different time points (before application of the disinfectant gel, immediately after palpation of the hands). dry, 1 minute later and 2 minutes later). The researchers also looked at the relationship between the amount of gel used and hand size to see if it was related to the drop in temperature.
Observations of the resulting images showed that handheld infrared technology was able to detect a significant (P<0.01) drop in skin temperature at all sites on the hand from before to after hand hygiene, illustrated by a dramatic color change. This, in turn, indicates appropriate sensitivity to monitoring the quality of hand hygiene practices.
The images also revealed that for one study participant with large hands, the reach of the hand sanitizer gel was insufficient to reach his fingertips, suggesting a possible role for using the device to calibrate an appropriate amount of sanitizer gel.
dr Boyce, a co-author of the Centers for Disease Control and Prevention’s Guide to Hand Hygiene in Healthcare and a contributor to the World Health Organization’s guidelines on hand hygiene in healthcare, told Medscape Medical News, “Thermal imaging is not a technology that is familiar to most people who deal with the disease infection prevention and control, but it offers several potential advantages over observations of hand hygiene technique.
Although previous studies have attempted to evaluate hand hygiene techniques using UV powder or liquid, using the thermal imaging camera has the advantage of simplicity, as no additional ingredients are required alongside the handheld devices.
This small study of an innovative handheld, smartphone-controlled thermal imaging camera suggests the potential utility of this approach for teaching and monitoring hand hygiene in healthcare settings. The thermal imaging camera is small, mobile and easy to use after uncomplicated setup on a smartphone.
In an interview with Medscape Medical News, Dr. Martinello of the Departments of Infection Prevention and Internal Medicine and Pediatrics at Yale School of Medicine adds, “This technology could potentially be used in a variety of settings, including teaching, assessing and assessing employee competency.”
However, Drs. Boyce and Martinello cautioned that due to body temperature variations, thermal imaging will be most useful as a teaching and assessment tool when baseline images can be compared to post-disinfection images. Further research is needed to validate the approach with different types (gel, foam) of hand sanitizer, different brands and different amounts, and with a larger variation in hand size, and to correlate the results with empirical observations of microbicidal efficacy.
Emily Landon, MD, Associate Professor of Medicine and Executive Medical Director, Infection Prevention and Control at UChicago Medicine, praised the concept of thermal imaging to study the quality of hand hygiene as “super creative and very innovative – just what we need in infection control.” .”
In an interview with Medscape Medical News, she noted, “Infection control is often about encouraging people to fight invisible problems and asking them to change their behavior without having anything to show for it. This approach makes it visible… We already use iOS mobile devices for B. data collection and monitoring, so connecting something to an iPhone is something familiar and already within reach. The idea is doable – it’s affordable, accessible, portable and easy to use… I love it!”
Am J Infect Control. Published online September 14, 2022. Full text
The study was independently supported. The equipment was purchased from the manufacturer FLIR. dr Boyce serves as a consultant to GOJO Industries and Diversey. Drs. Boyce and Martinello report no other relevant financial relationships. dr Landon discloses no relevant financial relationships.
Katie D. Schenk, PhD, @skibird613 is an infectious disease epidemiologist based in Washington DC.
For more updates, follow Medscape on Facebook, Twitter, Instagram and YouTube