"First-person view" of pathogen transmission and hand hygiene - use of a new head-mounted video capture and coding tool

Abstract

Background: Healthcare workers' hands are the foremost means of pathogen transmission in healthcare, but detailed hand trajectories have been insufficiently researched so far. We developed and applied a new method to systematically document hand-to-surface exposures (HSE) to delineate true hand transmission pathways in real-life healthcare settings.

Methods: A head-mounted camera and commercial coding software were used to capture ten active care episodes by eight nurses and two physicians and code HSE type and duration using a hierarchical coding scheme. We identified HSE sequences of particular relevance to infectious risks for patients based on the WHO 'Five Moments for Hand Hygiene'. The study took place in a trauma intensive care unit in a 900-bed university hospital in Switzerland.

Results: Overall, the ten videos totaled 296.5 min and featured eight nurses and two physicians. A total of 4222 HSE were identified (1 HSE every 4.2 s), which concerned bare (79%) and gloved (21%) hands. The HSE inside the patient zone (n = 1775; 42%) included mobile objects (33%), immobile surfaces (5%), and patient intact skin (4%), while HSE outside the patient zone (n = 1953; 46%) included HCW's own body (10%), mobile objects (28%), and immobile surfaces (8%). A further 494 (12%) events involved patient critical sites. Sequential analysis revealed 291 HSE transitions from outside to inside patient zone, i.e. "colonization events", and 217 from any surface to critical sites, i.e. "infection events". Hand hygiene occurred 97 times, 14 (5% adherence) times at colonization events and three (1% adherence) times at infection events. On average, hand rubbing lasted 13 ± 9 s.

Conclusions: The abundance of HSE underscores the central role of hands in the spread of potential pathogens while hand hygiene occurred rarely at potential colonization and infection events. Our approach produced a valid video and coding instrument for in-depth analysis of hand trajectories during active patient care that may help to design more efficient prevention schemes.

Keywords: Hand hygiene; Observation; Transmission risk; Video.

Fig. 1

Hierarchical coding system. Legend: HCW self, healthcare workers touching themselves; one hand touching the other hand of the same HCW was not considered

Fig. 2

Typical visual field of the head mounted GoPro® action camera and color-coded patient zone. Legend: This screenshot demonstrates the first-person view recorded from the head camera. Objects and surfaces belonging to the patient zone are colored with a green overlay and dotted outline

Fig. 3

Timeline chart of video #7. Legend: An excerpt of the coding timeline from video #7. X-axis: time from 0:00–3:25 minutes. Y-Axis from top to bottom: Hand hygiene action, hand-to-surface exposure (HSE) patient zone bare right hand inside, HSE to critical site with bare right hand, HSE outside patient zone with bare right hand, HSE inside patient zone with bare left hand, HSE at critical site bare left hand, HSE outside patient zone with bare left hand, HSE inside patient zone with gloved right hand, HSE to critical site with gloved right hand, HSE outside patient zone with gloved right hand, HSE inside patient zone with gloved left hand, HSE at critical site with gloved left hand, HSE outside patient zone with gloved left hand