Efficacy of the World Health Organization-recommended handwashing technique and a modified washing technique to remove Clostridium difficile from hands

Abstract

Background: The efficacy of the World Health Organization (WHO)-recommended handwashing technique against Clostridium difficile is uncertain, and whether it could be improved remains unknown. Also, the benefit of using a structured technique instead of an unstructured technique remains unclear.

Methods: This study was a prospective comparison of 3 techniques (unstructured, WHO, and a novel technique dubbed WHO shortened repeated [WHO-SR] technique) to remove C difficile. Ten participants were enrolled and performed each technique. Hands were contaminated with 3 × 10⁶ colony forming units (CFU) of a nontoxigenic strain containing 90% spores. Efficacy was assessed using the whole-hand method. The relative efficacy of each technique and of a structured (either WHO or WHO-SR) vs an unstructured technique were assessed by Mann-Whitney U test and Wilcoxon signed-rank test.

Results: The median effectiveness of the unstructured, WHO, and WHO-SR techniques in log₁₀ CFU reduction was 1.30 (interquartile range [IQR], 1.27-1.43), 1.71 (IQR, 1.34-1.91), and 1.70 (IQR, 1.54-2.42), respectively. The WHO-SR technique was significantly more efficacious than the unstructured technique (P = .01). Washing hands with a structured technique was more effective than washing with an unstructured technique (median, 1.70 vs 1.30 log₁₀ CFU reduction, respectively; P = .007).

Conclusions: A structured washing technique is more effective than an unstructured technique against C difficile.

Keywords: ASTM norm; Clostridium difficile; Cross-contamination; EN norm; Hand hygiene; Hand sanitizer; Handwashing; Infection control; Nosocomial infections.