An Ottawa doctor at the centre of an infection scare apologized to her patients on Monday as the city's health officials began alerting nearly 7,000 people that there is a slim chance they may have contracted hepatitis B, hepatitis C or HIV.

Ottawa Public Health says an endoscopic clinic operated by Dr. Christiane Farazli is where as many as 6,800 patients may have been exposed to viruses, although the chances of infection were slim.

The west-end clinic is located at 1081 Carling Ave., Suite 606, officials announced Monday afternoon.

OPH officials said that the College of Physicians and Surgeons of Ontario had inspected the clinic and found that "some infection prevention and cleaning protocols were not always followed."

The city's public health department has been investigating the clinic for the past several months after they became aware of "lapses in infection control."

Dr. Isra Levy, Ottawa's Medical Officer of Health, told a press conference on Monday that the procedures at the centre of the scare are endoscopic procedures, such as colonoscopies.

He said those are no longer being conducted at the clinic, which otherwise remains in operation.

"Ottawa Public Health believes there is a very low risk that patients may have been exposed to hepatitis B, hepatitis C or … the HIV virus during the tests," Levy said.

There is less than a one-in-three-billion chance that someone was infected with HIV, less than a one-in-50 million chance of infection with hepatitis C and less than a one-in-one million chance of hepatitis B infection, according to health officials.

"Even though the risk of infection for those who had the procedures related to this issue is very low, it is important to ensure that affected patients were made aware of the situation so that they can consider being tested for these infections if that is what they wish," Levy said.

Registered letters have been sent to approximately 6,800 patients who had an endoscopic procedure done at the clinic between April 2002 and June 2011.

The letters will advise the patients to consider being tested for the infections with a free blood test that can be ordered by their family doctor or through a walk-in clinic.

Levy said those letters will arrive at the intended addresses beginning Tuesday morning. He added that Ottawa Public Health has also been warning doctors to expect a high volume of patients concerned about the incident.

On Saturday, OPH announced there was a problem at a clinic in the area but it did not immediately identify which one. Levy said that was because "the public health system was not ready in this community over the weekend," leaving the clinic to be identified on Monday.

Ottawa Mayor Jim Watson defended OPH's handling of the health scare, saying that it was "new territory" and that there have been "lessons learned."

Dr. Fred Bray, a member of the Ontario Association of Gastroenterology's board of directors, said the College of Physicians and Surgeons of Ontario was given the authority to begin inspecting out-of-hospital clinics two years ago, and that paved the way for the discovery at Farazli's clinic.

According to the College of Physicians and Surgeons of Ontario website, Farazli graduated from the University of Montreal in 1973 and became an internal medicine specialist in 1978.

She issued an apology through Ottawa Public Health.

"I remain committed to the safety and well-being of my patients and am co-operating fully with OPH in providing patients with this notification," Farazli said in a statement.

"I sincerely regret that the issues that were identified in my facility occurred and I apologize for any inconvenience or anxiety that patients may experience upon receiving this notification. I would also like to reassure patients that the issues that led to this notification have been addressed and that I will be available to support them through this process."

Levy said Farazli has been working with Ottawa Public Health throughout the investigation.

It's still unclear what kind of problems the clinic had with its infection control. There is no evidence that anyone has been infected and the chance that anyone has been infected is low.

Ottawa Public Health has also opened a dedicated information hotline. The number is 613-580-2888. Anyone who underwent endoscopy in the facility between April 2002 and June 2011 and who has not received a letter by Oct. 25 should contact the hotline.

With a report from CTV Ottawa's Kate Eggins