Up to 6,800 patients at a private endoscopy clinic in Canada\'s capital could have been infected with HIV and the hepatitis B and C virus in the past ten years.As many as 6,800 patients at a private endoscopy clinic in Canada\'s capital could have been infected with HIV and the hepatitis B and C virus over the past ten years.Public health officials in Ottawa on Monday sent out 6,800 registered letters to former patients at a city clinic, but fear many of them have moved addresses and may no longer even be living in Canada.The public health scare comes after a spot check by officials found cross-contamination between dirty and clean scopes used for gastroscopes and colonoscopies at the clinic run by Dr Christiane Farazli on Ottawa\'s Carling Avenue.Ottawa officials believe that complex steps needed to completely sterilise equipment were not followed in full, resulting in the health scare.Dr Isra Levy, Ottawa\'s medical officer responsible for public health, said that the patients\' chances of infection with hepatitis B is one in a million, hepatitis C is one in 50 million, and HIV is less than one on three billion.He said the tips of scopes could have been contaminated along with another instrument that snips off small lumps in colons.Shannon McKarney is a former patient who had a colonoscopy at the clinic at the centre of the scare in 2007. She has since had an HIV test and has tested negative. Nevertheless, she says the entire experience has left her scared.\"Walking into a physician\'s office in Ontario, I assume that there is a board that is watching over the physician and their care,\" she said yesterday. \"And I would assume there is a board or regulatory body that is watching over the clinic they are running. So finding out that isn\'t the case, I\'m disturbed by it.\"While Canada has a medical system funded by federal and provincial governments, private-run clinics offer diagnosis and testing services.Ontario did not fully have control of private screening clinics until last year.The province\'s College of Physicians and Surgeons inspected Farazli\'s clinic in June and uncovered the lapses.They ordered Farazli to stop operating and told Ottawa public health officials. It has taken since June to compile the list of 6,800 former patients who may have been infected.The letters will tell the patients to contact health officials and they will have to have blood tests to see if they have contracted hepatitis B, C or HIV.