The FDA issued warning letters to duodenoscope manufacturers Olympus, Fujifilm and Pentax for failing to comply with federal law requirements to conduct postmarket surveillance studies to assess the effectiveness of reprocessing the devices.

The three manufacturers faced intense scrutiny after the Centers for Disease Control and Prevention linked cases of multi-drug resistant bacteria to duodenoscopes in 2013. The CDC reported that the infections were happening even though users followed the manufacturer’s cleaning and disinfection or sterilization instructions.

The FDA said that between January 2013 and December 2014 it received 75 reports involving about 135 patients suffering from carbapenem-resistant Enterobacteriaceae transmissions linked to the devices.

All three companies received warning letters in 2015 for a range of problems related to duodenoscopes, including failure to inform the FDA in a timely manner about patient injuries.

At the time, the FDA ordered the three companies to conduct postmarket surveillance studies to determine whether healthcare facilities were able to properly clean and disinfect the devices.

As part of their approved study plans, all three manufacturers were required to conduct a study to sample and culture reprocessed duodenoscopes that are in clinical use, to learn more about issues that contribute to contamination, as well as a human factors study to assess how well trained hospital staff are following the reprocessing instructions.

To date, Olympus has failed to conduct data collection, and Pentax and Fujifilm have failed to provide sufficient data, as required for their respective studies to sample and culture reprocessed duodenoscopes that are in clinical use, the agency said.

Olympus and Pentax also have not complied with requirements for their respective human factors studies to assess how well hospital staff follow reprocessing instructions. Fujifilm has been meeting its requirements for its human factors study, the agency said.

 “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 Jeff Shuren, director of the FDA’s Center for Devices and Radiological Health.