The importance of endoscope drying in infection prevention

Flexible endoscopes are indispensable tools in modern healthcare, facilitating the diagnosis and treatment of complex conditions across gastroenterology, pulmonology, urology, and other specialties. However, their intricate design renders them among the most challenging medical instruments to reprocess safely. While cleaning and high-level disinfection have long been recognised as pivotal for patient safety, one stage is often underestimated despite its equal importance: drying.

In many healthcare settings, drying is frequently regarded as a routine or secondary task. (1) Yet emerging evidence increasingly demonstrates that incomplete or improper drying can compromise the entire reprocessing workflow.

Healthcare professional preparing an endoscope for the drying process.

Moisture compromises reprocessing and storage

1. Moisture enables microbial survival

Even after thorough cleaning and disinfection, endoscope channels may retain small amounts of moisture. Studies consistently show that residual water creates an ideal environment for microbial survival and regrowth, particularly for waterborne, gram-negative bacteria such as Pseudomonas aeruginosa and Klebsiella pneumoniae. These microorganisms can persist on damp internal surfaces and recolonise channels within hours, posing a significant infection risk for subsequent patients. (2 3)

2. Moisture promotes biofilm formation

One of the strongest arguments for prioritising drying is its role in preventing biofilm development. Biofilms are notoriously resilient microbial structures that cling to internal lumen surfaces. Once formed, they are extremely difficult to eradicate, even with aggressive cleaning and disinfection. Crucially, biofilms do not form on dry surfaces. Residual moisture is the trigger that allows bacteria to attach, multiply, and form the protective matrix that makes them so difficult to remove. By ensuring complete drying, hospitals can significantly reduce the risk of biofilm formation and the long-term contamination issues that follow.

3. Consequences for infection prevention and device

Insufficient drying has been directly linked with contamination events and healthcare-associated outbreaks. Investigations reveal that endoscopes, even when deemed disinfected, may still harbour residual moisture alongside detectable ATP levels and viable microorganisms. (4 5 6) These findings emphasise a critical truth: an inadequately dried endoscope cannot be considered safe, irrespective of the quality of preceding reprocessing steps.

Beyond infection risk, retained moisture can damage the endoscope itself. Condensation and residual droplets contribute to corrosion, wear of internal components, and reduced device longevity. Proper drying therefore safeguards both patients and the investment made in high-value endoscopic equipment.

4. Proper drying protects the storage environment

Moisture does not only affect the instrument, it can compromise the entire storage system. Retained water may:

• Contaminate storage cabinets,

• Transfer waterborne microorganisms to other devices,

• Accelerate material degradation, and

• Reduce the device’s functional lifespan.

Even slight residual moisture in stored endoscopes can lead to recontamination before the next clinical use. Safe storage depends entirely on the instrument being fully dry, both internally and externally, before it enters the cabinet.

Modern solutions closing the safety gap

Given the complexity of modern endoscopes, manual or semi-manual drying techniques often fall short. Variations in guidelines and inconsistent workflows between facilities exacerbate the risk. This has driven adoption of automated systems that deliver repeatable, validated performance with full traceability.

Automated drying solutions, such as the Scirocco Endoscope Drying and Storage System, provide several advantages without complicating existing workflows. Using intelligent humidity sensing, Scirocco verifies the dryness of every channel, including difficult-to-reach components, ensuring that endoscopes leave the decontamination area fully patient-ready. With drying cycles of 5–7 minutes and secure storage options for up to 30 days, these systems mitigate clinical risks associated with residual moisture while supporting efficiency and compliance.

The Scirocco endoscope drying system, automatically and safely drying endoscopes.

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Conclusion: Drying is an critical step in endoscope reprocessing

While high-level disinfection remains central to infection prevention, proper drying completes the reprocessing cycle. Removing moisture:

• Prevents microbial survival,

• Inhibits early biofilm formation,

• Reduces the risk of outbreaks,

• Protects the integrity of the storage environment, and

• Ensures long-term patient safety.

  
  

As flexible endoscopes become increasingly complex and infection control requirements intensify, healthcare providers must adopt standardised, validated drying methods. Consistent and reliable drying is not an optional enhancement, it is a fundamental component of safe, modern clinical practice.

1. Muscarella, L. F. (2006). Inconsistencies in endoscope-reprocessing and infection-control guidelines: The importance of endoscope drying. American Journal of Gastroenterology, 101(7) https://doi.org/10.1111/j.1572-0241.2006.00712.

2. Muscarella, L.F. (2006). Inconsistencies in Endoscope-Reprocessing and Infection-Control Guidelines: The Importance of Endoscope Drying. The American Journal of Gastroenterology, 101(9), doi:https://doi.org/10.1111/j.1572-0241.2006.00712.x.

3. Haak, J., Klempien, I., Hans, J.B., Schaefer, S., Meyer-Bothling, K., Gatermann, S., Dirks, E.E., Konrat, K. and Arvand, M. (2025). Endoscope-associated outbreak of OXA-181- carbapenemase-producing Klebsiella pneumoniae and its implications for hygiene management. Journal of Hospital Infection, [online] 158, pp.19–28. doi:https://doi.org/10.1016/j.jhin.2025.01.016

4. Ofstead, C.L., Quick, M.R., Wetzler, H.P., Eiland, J.E., Heymann, O.L., Sonetti, D.A. and Ferguson, J.S. (2018). Effectiveness of Reprocessing for Flexible Bronchoscopes and Endobronchial Ultrasound Bronchoscopes. Chest, [online] 154(5), pp.1024–1034. doi:https://doi.org/10.1016/j.chest.2018.04.045.

5. Ofstead, C.L., Heymann, O.L., Quick, M.R., Eiland, J.E. and Wetzler, H.P. (2018). Residual moisture and waterborne pathogens inside flexible endoscopes: Evidence from a multisite study of endoscope drying effectiveness. American Journal of Infection Control, 46(6), doi:https://doi.org/10.1016/j.ajic.2018.03.002.

6. O'Horo, J. C., Farrell, A., Sohail, M. R., & Safdar, N. (2016). Carbapenem resistant Enterobacteriaceae and endoscopy: An evolving threat. American Journal of InfectionControl, 44(9), 1032–1036. https://doi.org/10.1016/j.ajic.2016.03.029