Ottawa Public Health says it will send letters to nearly 7,000 people who had procedures at a local medical facility to warn them they may have been exposed to Hepatitis B, Hepatitis C and HIV.

Stressing that he is not aware of any people who have become ill, Ottawa's medical officer of health Isra Levy said the letters are being sent so people can be made aware of the risk.

"Even though the risk of infection to those who had the procedures related to this issue is very low, I wanted to ensure that affected patients are made aware of the situation, so they can consider being tested for these infections," said Levy, at a hastily called news conference on Saturday afternoon.

Ottawa Public Health said it has been investigating an unnamed non-hospital facility for the past several months because of "lapses in infection control."

Because OPH doesn't know exactly when the lapse started, the 6,800 patients who will be contacted by registered letter next week cover a 10-year period.

"We don't know how long the problem has been going on for. We were notified at public health earlier in the summer," Levy said.

Levy wouldn't say exactly what the "lapse" was, but did say there are a number of reasons why problems arise including the improper cleaning of equipment and inadequate sterilization.

He stressed that the risk to patients is very low and that "at this time we are not aware of any person, any individual, who has become ill related to this lapse."

Levy said OPH will provide more information on the situation next week.