Researchers Investigate Improper High-Level Disinfection Practices During Endoscopy Procedures

In a retrospective cohort study conducted in four Veterans Affairs medical centers (VAMCs), Holodniy M, et al. (2012) sought to determine whether improper high-level disinfection practices during endoscopy procedures resulted in bloodborne viral infection transmission among veterans who underwent colonoscopy and laryngoscopy (ENT) procedures from 2003 to 2009.

Patients were identified through electronic health record searches and serotested for human immunodeficiency virus (HIV), hepatitis C virus (HCV), and hepatitis B virus (HBV). Newly discovered case patients were linked to a potential source with known identical infection, whose procedure occurred no more than one day prior to the case patients procedure. Viral genetic testing was performed for case/proximate pairs to determine relatedness.

The researchers report that of 10,737 veterans who underwent endoscopy at four VAMCs, 9,879 patients agreed to viral testing. Of these, 90 patients were newly diagnosed with one or more viral bloodborne pathogens (BBPs). There were no case/proximate pairings found for patients with either HIV or HBV; 24 HCV case/proximate pairings were found, of which seven case patients and eight proximate patients had sufficient viral load for further genetic testing. Only two of these cases, both of whom underwent laryngoscopy, and their four proximates agreed to further testing. None of the four remaining proximate patients who underwent colonoscopy agreed to further testing. Mean genetic distance between the two case patients and 4 proximate patients ranged from 13.5 percent to 19.1 percent.

The investigators concluded that exposure to improperly reprocessed ENT endoscopes did not result in viral transmission in those patients who had viral genetic analysis performed. Any potential transmission of BBPs from colonoscopy remains unknown.

Reference:  Holodniy M, et al. Results from a Large-Scale Epidemiologic Look-Back Investigation of Improperly Reprocessed Endoscopy Equipment. Infection Control and Hospital Epidemiology.  Vol. 33, No. 7.  July 2012