Wetting gaps in hand disinfection
Wetting gaps (Gaps) are areas of skin that are not, or not completely, wetted with disinfectant during hand disinfection. Since pathogens can survive in these gaps, they pose a significant risk of infection. These gaps frequently occur on the thumbs, fingertips, nail edges, and backs of the hands [Fig. 1].
Causes & Relevance
- Application errors: Too little Amount of disinfectant, too short an exposure time or omitting areas of skin.
- Risk: Germ reduction is insufficient in areas where contact was limited. Pathogens can survive there and continue to be transmitted despite hand disinfection.
Prevention through training
To ensure that gaps in coverage do not go unnoticed, regular training is an important part of infection prevention:
Conventional methodUV control
The widely used UV method employs fluorescent test agents. The test is then checked under UV light, usually in a UV box.
- The hands are rubbed with a fluorescent testing agent.
- After application, the hands are examined under UV light. This makes moistened skin areas and any gaps in coverage visible.
- The training reveals which areas of the hand were not sufficiently moistened.
Modern method: DesiCoach®
At the DesiCoach® method Two training fluids are used. The two-phase training allows for monitoring and subsequent optimization of the wetting.
- The hands are first rubbed with a transparent dye solution. As they dry, the areas of skin that have been dyed and any gaps in the dye coverage become clearly visible [Fig. 2].
- A stain remover solution is then used. The wetting becomes visible during the application. This immediate feedback helps to determine the correct procedure. Rubbing-in technique to correct in a targeted manner and to train correct movement sequences intuitively [Fig. 3].
Loud KRINKO/RKI recommendations (page 1206) are Training courses on the Indications for hand disinfection in conjunction with practical training for all employees in healthcare facilities at least annually and to carry out these measures promptly upon notification of problems in this area.

Fig. 1: Schematic representation of typical wetting gaps. Light blue: Often forgotten. Dark blue: Very often forgotten.

Fig. 2: Visualization of wetting gaps and dosage amount during training with the DesiCoach® dye

Fig. 3: Immediate visualization of wetting during training with the DesiCoach® stain remover