Alberta Health Services is notifying 141 women who may be at risk of infection after undergoing endovaginal ultrasounds at an Edmonton fertility clinic.

Patients who underwent that type of ultrasound at Edmonton's Royal Alexandra Hospital last month are being warned they may be at "exceedingly low risk" of blood-borne and sexually transmitted infections.

"We believe that the risk of any infection transmission related to this particular event is near zero — as close to zero as it could possibly be," Dr. Mark Joffe, AHS vice-president and medical director for northern Alberta, told a news conference.

"We sincerely apologize. We regret that these events have happened. We regret that we need to connect with women. We understand, we know, that this is a very stressful time for them and we are now potentially adding to that stress, and for that we are sincerely sorry."

Human error is being blamed for what health officials are calling a "possible lapse in cleaning and disinfection procedures."

"This includes inconsistent tracking and documentation of the number of reprocessed probes available for endovaginal ultrasounds ... and overscheduling of procedures," AHS said in a news release.

The patients being notified all underwent a procedure where an examiner places a thin, covered wand inside the vagina, and directs the probe toward the uterus and ovaries. The procedures were performed between Nov. 14 and Nov. 20 at the Regional Fertility and Women's Endocrine Clinic at the Royal Alexandra Hospital.

Endovaginal exam instruments may not have been disinfected0:27

Phone calls to the women began Thursday, Joffe said. They will be told that AHS "cannot be absolutely certain" that all procedures for reprocessing medical devices, including cleaning and disinfection, were properly performed, he said.

"There may have been gaps in that process or gaps in the documentation that those various steps were conducted."

Testing will be offered to any woman who feels she needs reassurance, but Joffe said the risk is so low he doesn't think it is necessary.

AHS became aware of the issue on Nov. 20. The previous day, a Sunday, had been very busy in the clinic, Joffe said, with a large number of patients undergoing ultrasound procedures.

"Because of the large number of women who were examined on that day, we looked at the records for cleaning and disinfection of the ultrasound probes that are used, and we were concerned that some of our documentation was not what we would have liked to have seen.

'Documentation challenges'

"A large number of probes were cleaned and disinfected and we couldn't be absolutely certain that every step of our cleaning and disinfection process had been followed."

Further checking showed that there were "documentation challenges" between Nov. 14 and Nov. 20, he said.

"We're confident that there were no similar challenges in the days and months leading up to that," Joffe said. "This was confined to a short period of time."

Joffe said AHS has reviewed its procedures and is confident the risks seen in November won't be repeated.

Staff have received more education, limits have been put in place on the number of procedures that can be done each day, and supervision has been increased, he said.