Endoscope Reprocessing in the Age of COVID-19

In times of uncertainty, there’s little room for error

In a recent publication in the American Journal of Infection Control, researcher and author Cori L Ofstead, MSPH et al. (2019) examined the “Challenges in achieving effective high-level disinfection in endoscope reprocessing.” In this article, which we have made available to healthcare professionals at no cost, Ofstead details multiple potentially alarming points of failure repeatedly observed during real-world endoscope reprocessing scenarios.

According to Ofstead’s article, concerning evidence exists that endoscope reprocessing may frequently be error-prone, ineffective, and potentially represent danger of contamination exposure to patients. On review of Ofstead’s observations, we’ve dubbed the following factors as hidden points of failure that may contribute to ineffective endoscope reprocessing:1

  1. Human factors contributing to non-adherence to guidelines, standards, and manufacturer instructions for use (IFU)
  2. Clinical use of endoscopes with visible damage
  3. Use of products that may interfere with reprocessing
  4. Presence of residual soil after manual cleaning
  5. Rinse-water quality issues
  6. Retained moisture in fully-reprocessing endoscopes

Examples of improper high-level disinfection (HLD) practices observed by Ofstead's team included use of expired products, improper HLD temperature, inadequate testing for the minimum effective concentration of HLDs, and improper storage of MEC test strips.

"We are troubled by mounting evidence demonstrating that HLD effectiveness is suboptimal in real-world settings." - Cori Ofstead, MSPH

Implications of ineffective endoscope reprocessing in the age of COVID-19

According to the World Health Organization (WHO), SARS-CoV-2 airborne transmission may be possible in procedures or support treatments that produce aerosols such as endotracheal intubation and bronchoscopy. Airborne transmission is different from droplet transmission as it refers to the presence of microbes within a droplet nuclei and can remain in the air for long periods of time and be transmitted to others at a distance greater than one meter or 3.28 feet.2

Risk of infection resulting from improper reprocessing of endoscopes is causing alarm among leaders in pulmonology and otolaryngology.1 The SARS-CoV-2 virus has a lipid envelope structure that makes it more resistant to cleaning by enzymatic detergents.3 Endoscopes must be disinfected, according to manufacturer IFUs, after pre-cleaning by detergent. Due to the resistance of the virus to pre-cleaning, it decreases the safety margin to achieve appropriate HLD.

While HLD is an acceptable reprocessing modality of semi-critical endoscopes such as bronchoscopes, there are published articles broaching the topic for the consideration of institution to shift from HLD to sterilization of these scopes to improve patient safety.

The case for sterilization

Given the alarming implications of the Ofstead study regarding potential hidden points of failure in high-level disinfection of flexible endoscopes, it’s possible infection control teams in facilities around the world are considering the option to sterilize flexible endoscopes where feasible.*

"The margin for error with high-level disinfection is simply not large enough to tolerate any deviations from optimal practices." - William A. Rutala, Ph.D, M.P.H1

The difference between sterilization and HLD is a sterilization process must inactivate a broad spectrum of microorganisms, including resistant bacterial spores, whereas HLD eliminates microorganisms, but not bacterial spores.4

ASP STERRAD™ Sterilization Systems use low-temperature hydrogen peroxide gas plasma to terminally sterilize a wide range of instruments. The STERRAD NX™ System and STERRAD™ 100NX System has a technology capable of penetrating long and narrow lumen yet gentle enough to reprocess delicate and heat-sensitive instruments such as flexible endoscopes.

STERRAD™ Systems technology, coupled with ASP’s robust device validations “worse-case” methodology, provides the margin of error necessary for real-world reprocessing.

Today, there are hundreds of flexible endoscopes from leading manufacturers that have been validated for use in STERRAD Systems. In order to be validated for terminal sterilization in STERRAD™ Systems, the device manufacturer and ASP jointly perform a series of validations such as sterilization efficacy and material or functional compatibility. ASP’s experienced scientists and microbiologists challenge instruments to ensure they demonstrate a sterility assurance level (SAL) of 10-6 and perform rigorous repeated-cycles testing.

For a list of flexible endoscopes that have been validated for sterilization in STERRAD™ Systems, check out our STERRAD™ Sterility Guide (SSG).

If you’d like a consultation with an ASP expert regarding any information shared in this blog, contact us today.


  1. Ofstead CL, Hopkins KM, Buro BL, Eiland JE, Wetzler HP. Challenges in Achieving Effective High-Level Disinfection in Endoscope Reprocessing. Am J Infect Control 2019: 10.1016.

  2. World Health Organization. Modes of transmission of virus causing COVID-19: implications for IPC precaution recommendations. Available: https://www.who.int/news-room/commentaries/detail/modes-of-transmission-of-virus-causing-covid-19-implications-for-ipc-precaution-recommendations. Accessed July 7, 2020.

  3. Pritchett MA, Oberg CL, Belanger A, De Cardenas J, Cheng G, Nacheli GC, Franco-Paredes C, Singh J, Toth J, Zgoda M, Folch E. Society for Advanced Bronchoscopy Consensus Statement and Guidelines for bronchoscopy and airway management amid the COVID-19 pandemic. Journal of Thoracic Disease 2020: 10.21037.

  4. Center for Disease Control. Guideline for Disinfection and Sterilization in Healthcare Facilities. May 2019.



Priscilla Serwaa Omari-Baah

Marketing Associate

Linda Gordon

Linda Gordon

Marketing Manager



The content of this website is aimed exclusively at healthcare professionals (HCPs) and not at the general public. Please confirm by clicking below that you are a healthcare professional, duly authorized to practice in your field. ASP EMEA declines all responsibility in case of unauthorized consultation.