Two recent deaths at Ronald Reagan UCLA Medical Center in Los Angeles have been linked to the superbug carbapenem-resistant enterobacteriaceae (CRE). As many as 179 patients have possibly been exposed to what officials believe were contaminated endoscopic tools. At the moment, however, it’s unclear whether the tools' contamination with the dangerous bacterium was due to a breach in cleaning protocol or a fault in the instruments' design.

Seven additional patients at the medical center have been confirmed to have a CRE infection, and, as a university statement said, the infection was “a contributing factor” in the two confirmed deaths, The Associated Press reported.

The specific tools traced to this outbreak are known as duodenoscopes, and they differ from traditional endoscopes in their design. Because of this, the tools are especially tricky to clean. Endoscopes are devices inserted down the throats of patients during an endoscopy, a non-surgical procedure used to look inside the body to spot a range of disorders, from cancer to gallstones.

AP reported that the two duodenoscopes in question were sterilized “according to the manufacturer’s specifications,” but in this case the cleaning process was not thorough.

Dr. Alex Kallen, an epidemiologist in the CDC’s Division of Healthcare Quality Promotion told the Los Angeles Times that he doesn’t believe that a breach in the cleaning protocol was the reason for the outbreak.

Duodenoscopes are equipped with an “elevator channel,” which some experts suspect may have harbored a buildup of the dangerous bacteria. The FDA believes that, at this moment, keeping these instruments on the market is in the best interest of the American public.

CRE causes infections of the bladder or lungs and can lead to coughing, fever, or the chills. It is just one of many bacterial infections that has evolved a resistance to all known antibiotics. If left untreated, in some cases, these infections can prove deadly.

HealthDay reported that in the American Southeast community hospitals have seen a fivefold increase in the number of cases of superbugs in the past five years, with CRE being the most reported of these. According to the CDC, CRE infections can contribute to death in up to half of patients seriously infected with a hospital-borne superbug. The World Health Organization described CRE as “an increasingly serious threat to global health that requires action.”