Efficacy of 'sporicidal' ready-to-use disinfectant wipes against Clostridioides difficile: comparison of standard and modified EN 17846 wiping procedures.

Background

Sporicidal surface disinfection is essential for preventing the transmission of Clostridioides difficile in healthcare settings. However, not all products with marketed sporicidal claims have demonstrated consistent efficacy. Standardized evaluation of sporicidal efficacy is based on both quantitative suspension testing (EN 17126) and the practice-oriented 4-field surface test with mechanical action (EN 17846). While these methods are well established, methodological aspects related to wiping trajectories are under discussion.

Methods

Five ready-to-use disinfectant wipes with sporicidal claims were evaluated against C. difficile spores using EN 17126 suspension tests and EN 17846 4-field surface tests. In the surface test, both the standard wiping trajectory and a modified linear wiping procedure were applied.

Results

Products with sporicidal efficacy confirmed in two independent laboratories fulfilled the efficacy criteria in both suspension and surface tests. Among products without such confirmation, sporicidal activity was observed, whereas others failed to meet efficacy requirements. The modified wiping procedure resulted in lower reductions on the primary field and increased transfer to secondary fields in the water control. While products with clearly effective or ineffective profiles were not meaningfully affected, borderline-performing products showed reduced efficacy under the modified procedure.

Conclusion

Comparative evaluation under standard and modified EN 17846 conditions demonstrated that increased methodological stringency affects the results of borderline-performing products, while clearly effective products remain consistently effective. These findings indicate that wiping trajectory is a relevant methodological parameter in EN 17846 testing, particularly for products performing close to the efficacy threshold.