Endoscope storage time: assessment of microbial colonization up to 21 days after reprocessing

Background: Insufficient data exist for how long endoscopes can be stored after reprocessing. Concern about possible microbial colonization has led to various recommendations for reprocessing intervals among institutions, with many as short as 5 days. A significant cost savings could be realized if it can be demonstrated that endoscopes may be stored for as long as 21 days without risk of clinically significant contamination.

Objective: To demonstrate whether flexible endoscopes may be stored for as long as 21 days after reprocessing without colonization by pathogenic microbes.

Design: Prospective, observational study.

Setting: Tertiary care center.

Endoscopes: Four duodenoscopes, 4 colonoscopes, and 2 gastroscopes.

Intervention: Microbial testing of endoscope channels.

Main outcome measurements: Culture results at days 0, 7, 14, and 21.

Results: There were 33 positive cultures from 28 of the 96 sites tested (29.2% overall contamination rate). Twenty-nine of 33 isolates were typical skin or environmental contaminants, thus clinically insignificant. Four potential pathogens were cultured, including Enterococcus, Candida parapsilosis, α-hemolytic Streptococcus, and Aureobasidium pullulans; all were likely clinically insignificant as each was only recovered at 1 time point at 1 site, and all grew in low concentrations. There were no definite pathogenic isolates.

Limitations: Single center.

Conclusion: Endoscopes can be stored for as long as 21 days after standard reprocessing with a low risk of pathogenic microbial colonization. Extension of reprocessing protocols to 21 days could effect significant cost savings.