Ottawa's public health officials say letters will start going out to 6,800 people who may have been exposed to HIV, Hepatitis B and C on Monday.
The community was alerted of the potential health scare Saturday afternoon.
City officials have confirmed the failure in the system was by one doctor at an Ottawa clinic.
Officials say the name of the clinic and which procedure exposed patients to infection will not be released to avoid panic and fear.
The city's Medical Officer of Health Dr. Isra Levy said after people are alerted by registered mail, the city will open up a hotline to move people through the process of being tested.
Levy said the risk of infection is very low.
However, the lapse in infection control may have been going on for a decade.
