Avoid test strips illegally marketed to assess duodenoscope cleanliness

Sept. 13, 2019

The Food and Drug Association (FDA) has announced that it is aware that some healthcare facilities are using adenosine triphosphate, or ATP test strips, to assess duodenoscope cleaning. These test strips claim to indicate the presence of live microbes inside of duodenoscopes. However, to date, the FDA is not aware of any legally marketed ATP test strips cleared by the agency for this use, which means the FDA has not reviewed them for effectiveness in assessing reprocessing. Prior to being legally marketed in the U.S., an FDA premarket review is necessary to help assure that ATP test strips are adequately validated and properly labeled.

In a study funded by the National Institutes of Health, 20 clinically used duodenoscopes underwent reprocessing per current guidelines. After manual cleaning, ATP samples were obtained from the elevator, within the proximal biopsy port, and by flushing of the biopsy channel. After high-level disinfection, aerobic cultures of the elevator and biopsy channel were obtained using sterile technique. The researchers concluded that ATP sampling appears to correlate poorly with terminal culture results and cannot be recommended as a surrogate for terminal cultures.

In addition, a report from the Department of Health and Human Services "Duodenoscope Surveillance Sampling & Culturing: Reducing the Risks of Infection" (https://www.fda.gov/media/111081/download) states that ATP tests cannot distinguish between high-concern and low/moderate-concern organisms. For these reasons, rapid ATP testing, while useful as a marker for the cleaning process, is not sufficiently sensitive to be used as a marker for the adequacy of the high-level disinfection process. For healthcare facilities that choose to assess the quality of their cleaning and high-level disinfection processes, ATP tests may be incorporated into a facility’s procedures after the cleaning process, but ATP tests should not be used in lieu of endoscope sampling and culturing after high-level disinfection. Testing cleaning adequacy after high-level disinfection is also not appropriate because the intent of cleaning monitoring is to identify and correct inadequate cleaning processes prior to disinfection or sterilization.

The FDA says it has contacted manufacturers of ATP test strips advising them of the FDA’s requirements for manufacturing, testing and labeling for medical devices marketed for assessing duodenoscope reprocessing and has requested they submit data to support the clearance of the strips for this use.

As for any unauthorized use of a medical device, if the companies do not come into compliance, the agency will consider whether to take enforcement action if necessary. In the meantime, the FDA is asking healthcare facilities not to rely on these test strips to assess duodenoscope cleaning.