A report by Democrats on the U.S. Senate’s health committee issued this week blames hospitals, medical device companies and the FDA for the deadly outbreaks of so-called “superbug” infections linked to duodenoscopes.

The devices are used for a procedure called endoscopic retrograde cholangiopancreatography, in which a reusable tube-like camera is inserted into the throat of a patient. More than 500,000 ERCPs using the devices are performed in the U.S. annually. Hospitals in Connecticut, Virginia, California and Washington state all reported superbug outbreaks in February and March 2014, some of which led to patients’ deaths.

Staffers under Sen. Patty Murray (D-Wash.), the ranking member of the Senate Health, Education, Pensions & Labor Committee, found that it took 17 months for ‘scope makers Olympus (TYO:7733), Fujifilm Holdings‘ (TSE:4901) and Hoya (TYO:7741) subsidiary Pentax to raise the alarm about the infections.

“At least 68 patients in 7 different hospitals in the U.S. were infected with antibiotic-resistant bacteria linked to duodenoscopes during this period,” according to the HELP panel’s report. “Between 2012 and spring 2015, closed-channel duodenoscopes were linked to at least 25 different incidents of antibiotic-resistant infections that sickened at least 250 patients worldwide.”

The report also found that Olympus, which owns some 85% of the U.S. market for duodenoscopes, knew as early as 2013 that a new “closed-channel” design allowed the devices to harbor and spread bacteria even after sterilization procedures.

“Olympus never brought this information to FDA, and did not alert hospitals, physicians or patients in the U.S. to the risk of infection until February 2015,” according to the report.

Mark Miller, corporate & medical communications VP at Olympus, said in prepared remarks that the company spent several months cooperating with the Senate panel’s enquiry.

“We appreciate that the staff report noted Olympus’ cooperation and that the report demonstrates the shared responsibilities of duodenoscope manufacturers, hospitals, manufacturers of automated endoscope reprocessors, and the FDA, each of which can contribute to increasing patient safety. Although we do not agree with all of the report’s conclusions, we are closely reviewing the recommendations in the report as part of Olympus’ ongoing efforts to increase patient safety associated with use of Olympus duodenoscopes,” Miller said.

The Senate report also found that Olympus, Fujifilm, Pentax and automated sterilization provider Custom Ultrasonics “failed to meet the obligations placed upon them by the current regulatory system.”

“Two of the manufacturers failed to seek FDA clearance before selling the ‘closed-channel’ duodenoscopes, all failed to adequately test whether the scopes could be cleaned reliably in real-world settings, and fully comply with adverse events reporting requirements,” according to the report.

But the companies were not solely to blame for the superbug outbreaks, according to the report.

“Additionally, although at least 16 separate U.S. hospitals traced antibiotic-resistant infections directly to duodenoscopes, the hospitals generally did not raise alarms about these infections with federal regulators. It appears that not a single hospital that experienced infection outbreaks tied to the duodenoscopes sent the required adverse event form to the device manufacturers,” Murray’s aides wrote. “When hospitals did take required action to report adverse events to device manufacturers it was often late, notification was made informally by phone or email, and reports were not inclusive of all the information necessary for the manufacturers to themselves submit accurate and complete information to FDA.”

And the FDA played its part in the deadly fiasco, they wrote, citing the safety watchdog’s often-maligned Manufacturer & User Facility Device Experience database, which is designed to track adverse events linked to medical devices.

“Problems with FDA’s outmoded adverse event device database, as well as slow and incomplete reporting by manufacturers and hospitals, appear to have left FDA staff unable to develop an accurate sense of the frequency and severity of the infection outbreaks. FDA was also unaware that by early 2013, 2 independent labs in Europe had documented the Olympus closed-channel duodenoscope remaining contaminated after repeated cleaning, or that a Dutch Health Ministry report in 2013 had already concluded that Olympus did not have the data to show their cleaning instructions worked consistently and effectively,” according to the report.

In March 2014, hospitals in Los Angeles and Connecticut reported superbug outbreaks linked to the scopes. Cedars-Sinai Medical Center reported 4 infections and 67 more at-risk patients. coinciding with a hospital in Hartford, Conn., reporting a similar outbreak involving at least 5 infections and more than 280 potential exposures.

The Cedars-Sinai cases, like the larger number of infections and potential exposures reported in February at the UCLA Ronald Reagan Medical Center in Los Angeles, involved a family of germs called carbapenem-resistant Enterobacteriaceae. The bacteria identified in the Hartford Hospital outbreak was a drug-resistant strain of E.coli. Seven patients were infected with CRE during endoscopies at the UCLA teaching hospital between Oct. 3 and Jan. 28, and 2 died. Officials warned at the time that as many as 179 people may have been exposed to the so-called superbug.

Between 2012 and 2014, at least 32 patients at Virginia Mason Medical Center were infected with strains of multidrug-resistant E. coli bacteria spread through contaminated scopes that had been sterilized to the manufacturer’s guidelines, according to state health officials. At least 11 people eventually died, though the role of the superbug in their demise was unclear because all the patients were critically ill at the time of their infection, Washington state public health officials said.

The outbreaks prompted the FDA to inspect 11 plants where the 3 companies make the endoscopes, leading to the August 12 warning letters to Olympus, Fujifilm and Pentax. The FDA said it found numerous violations at the plants, ranging from inadequate quality controls to failures to report serious adverse events, including deaths. The violations turned up at plants in Japan, New Jersey, Pennsylvania and California, according to the FDA.