The validity of adenosine triphosphate measurement in detecting endoscope contamination

Area of Science:

• Gastroenterology
• Infection Control
• Medical Device Reprocessing

Background:

• Endoscopic procedures are crucial for diagnosing gastrointestinal diseases but carry a risk of infection transmission.
• Current microbiological testing of endoscopes in Australia occurs monthly to quarterly, potentially lagging behind frequent use and increasing contamination risks.
• The study addresses the need for more timely detection of endoscope contamination.

Purpose of the Study:

• To assess the utility of adenosine triphosphate (ATP) measurement alongside standard microbiological cultures in identifying endoscope contamination prior to high-level disinfection.
• To confirm the effectiveness of manual cleaning procedures in reducing both ATP levels and microbial load (cfu/mL).

Main Methods:

• Seventeen gastroscopes and 24 colonoscopes from a clinical endoscopy unit were sampled at three distinct cleaning stages before high-level disinfection.
• Both colony counts (cfu/mL) and ATP measurements (relative light units - RLU) were performed on the collected samples.

Main Results:

• A significant positive correlation was found between ATP (RLU) and microbiological load (cfu/mL) for both colonoscopes (r=0.497, P < 0.0001) and gastroscopes (r=0.377, P = 0.0138).
• Both ATP and cfu/mL values decreased significantly (P < 0.005) after precleaning and manual cleaning stages.
• These findings indicate that cleaning procedures effectively reduce bioburden.

Conclusions:

• ATP measurement demonstrates a significant correlation with microbiological cultures for detecting contamination on endoscopes before high-level disinfection.
• Precleaning and manual cleaning significantly reduce both ATP levels and overall microbiological load.
• ATP measurement offers a rapid, easily interpretable screening tool for endoscope cleanliness, warranting further investigation for routine use.