so does everyone else . '' Parker 's attorney did not return a call from CNN on Thursday . Authorities said Parker knew she had hepatitis C , a contagious liver disease . Hepatitis C can lead to cirrhosis or liver cancer , according to the Centers for Disease Control and Prevention . Parker believes she contracted the virus through using heroin and sharing needles with other users while she lived in New Jersey in 2008 , authorities said . According to an affidavit filed by an investigator with the Food and Drug Administration , Rose Medical Center knew Parker tested positive for hepatitis C . She was counseled on how to limit her exposure to patients . Parker worked at Rose Medical Center from October 2008 to April 2009 , said Jeff Dorschner , a spokesman for the U.S. attorney for Colorado . Parker 's employment was terminated after she failed a hospital-ordered drug test , said Leslie Teegarden , spokeswoman for Rose Medical Center . The tests were ordered after co-workers reported `` suspicious behavior , '' Teegarden said Thursday . Rose Medical Center contacted about 4,700 patients who may have been exposed to the virus , according
-LRB- CNN -RRB- -- Nineteen former patients at a Denver , Colorado , hospital have tested positive for hepatitis C , federal prosecutors said Thursday as they announced new charges against a former hospital employee accused of exposing the patients to the virus . A hospital worker is accused of injecting herself and using unclean syringes for patients . Prosecutors charged Kristen Diane Parker with 21 counts of tampering with a consumer product and another 21 counts of obtaining a controlled substance by deceit or subterfuge , according to an indictment . Parker , 26 , had previously faced three federal counts from earlier this month . Parker , who worked as a surgical technician at Rose Medical Center in Denver , is accused of injecting herself with syringes that held patients ' pain medication Fentanyl , then replacing the pain medication in the syringes with saline , according to a statement from the office of the U.S. attorney for Colorado . In a statement to police during the investigation , Parker said , `` I ca n't take back what I did , but I will have to live with it for the rest of my life , and