(NaturalNews) A Colorado hospital technician has admitted to stealing syringes from the facilities where she worked and replacing them with needles that she had previously used, thus exposing patients to hepatitis C.Hepatitis C is a contagious disease of the liver that can lead to scarring or even failure of the organ. Kristen Diane Parker, the technician, said she probably contracted the disease in 2008 while using heroin and sharing needles in New Jersey.From October 2008 to April 2009, Parker was a surgical technician at Rose Medical Center in Denver. She has admitted that she stole syringes filled with the opioid painkiller fentanyl and replacing them with used syringes filled with saline solution. She then injected herself with the fentanyl secretly in the hospital bathroom.Nine patients who underwent surgery at the hospital while Parker worked there have tested positive for hepatitis C, and investigators are performing genetic tests to determine if they were infected by Parker. The hospital has contacted another 4,700 patients who underwent surgery at that time to warn them that they might have been infected, even though the odds are slim."We are taking a very conservative and cautious approach by contacting everyone who had surgery during this broad time period," the hospital said. "It is likely that most of the patients who receive letters will not have been exposed to hepatitis C."Audubon Ambulatory Surgical Center in Colorado Springs is also contacting 1,200 patients who received injections there while Parker was an employee between May and July 2009.Parker has been charged with three drug-related offenses. If she is found to have actually infected anyone with hepatitis C or otherwise caused harm to a patient, her maximum sentence will be 20 years. If any of the patients dies from the disease, she could serve life in prison.Sources for this story include: www.cnn.com