The drug-resistant superbug known as CRE was likely transmitted to the Los Angeles patients by contaminated medical scopes during endoscopic procedures that took place between October 2014 and January 2015, a university statement said.
The bacteria may have been a “contributing factor” in the deaths of two patients, according to the university.
UCLA says it sterilized the scopes according to manufacturer standards, but it is now using a decontamination process “that goes above and beyond the manufacturer and national standards.”
Fears linger that more confirmed cases of the bacteria could emerge.
UCLA said infections may have been transmitted through two endoscopes used during the diagnosis and treatment of pancreatic and bile-duct problems.
"We notified all patients who had this type of procedure, and we were using seven different scopes,” UCLA spokeswoman Dale Tate said. “Only two of them were found to be infected. In an abundance of caution, we notified everybody.”
Federal, state and local health officials are investigating the outbreak in Los Angeles, and warning letters, as well as home testing kits, have been sent to those potentially at risk.
The Associated Press contributed to this report.