Three major suppliers of duodenoscopes have received warning letters from the FDA for failing to conduct postmarket surveillance studies into the effectiveness of reprocessing the devices.

Olympus, Fujifilm and Pentax were ordered by the FDA in 2015 to conduct studies to assess whether healthcare facilities were able to properly clean and disinfect the devices.

The manufacturers were required to conduct studies to sample and culture reprocessed duodenoscopes in clinical use in an effort to determine which tissues contribute to contamination. They were also required to conduct studies into hospital staff factors that influence adherence to reprocessing instructions.

However the FDA says the scope manufacturers have so far failed to meet their study obligations to varying degrees, with Olympus not starting data collection and Pentax and Fujifilm providing insufficient data.

“The FDA has taken important steps to improve the reprocessing of duodenoscopes, and we’ve seen a reduction in reports of patient infections, but we need the required postmarket studies to determine whether these measures are being properly implemented in real world clinical settings and whether we need to take additional action to further improve the safety of these devices,” said Dr Jeff Shuren, director of the FDA’s Center for Devices and Radiological Health.

In 2013, the FDA learned about a potential association between multi-drug resistant bacteria and duodenoscopes. Upon further investigation, it became clear that cases of infection were occurring despite confirmation that device users were following manufacturer cleaning and disinfection or sterilisation instructions.

Since then, the FDA has worked with the Centers for Disease Control and Prevention (CDC), and the American Society for Microbiology to develop voluntary standardized protocols for duodenoscope surveillance sampling and culturing.

The FDA say it now expects the manufacturers to submit plans to outline how the study milestones will be achieved, or face penalties.