Lab Tech Gets 39 Years for Infecting Patients With Hepatitis A New Hampshire hospital lab technician who pleaded guilty in August to infecting at least 46 people with hepatitis C was sentenced today to 39 years in prison. David Kwiatkowski, 34, a former lab technician at Exeter Hospital, admitted to stealing syringes of the anesthetic fentanyl intended for patients, injecting his own arm and then refilling those empty syringes with saline, according to the United States Attorney's Office in New Hampshire. Read about Kwiatkowski's indictment. Kwiatkowski pleaded guilty in August exchange for a lighter prison sentence, according to the plea agreement obtained by ABCNews.com. Kwiatkowski tested positive for hepatitis C in June 2010, and passed the infection on to the hospital patients who were injected with his used, saline-filled syringes, according to the plea agreement. At least one patient he treated died in Kansas, and a coroner determined hepatitis C played a role in that death. According to the plea agreement, Kwiatkowski had been fired or forced to quit for stealing and replacing syringes at least as far back 2008, but he would simply move on to the next hospital. For example, the University of Pittsburgh Medical Center fired Kwiatkowski in May 2008 after an employee saw him take a fentanyl syringe from the operating room, and he was later found with three empty syringes on his person, according to the plea agreement. Less than two weeks after that, Kwiatkowski got a job at the VA Medical Center in Baltimore. A patient who received care from him on May 27, 2008, at the Baltimore hospital later tested positive for the same strain of hepatitis C that Kwiatkowski has. "If he knew that he was infected and he put those needles back on the shelf, that is the definition of evil," Dr. Richard Besser, ABC News' chief health and medical editor, told "Good Morning America" last summer. Anyone who was in those hospitals when he was working there is potentially at risk. We're talking tens of thousands of people. Hepatitis C is a liver disease that can last a few weeks or for the rest of a patient's life, according to the Centers for Disease Control and Prevention. The virus is spread through blood, and there is no vaccine. Symptoms include vomiting, abdominal pain and jaundice. Read about the thousands of patients who needed to be tested for hepatitis C. The Associated Press contributed to this report