BOSTON -- A medical technician was sentenced Monday to 39 years in prison for infecting at least 45 hospital patients with hepatitis C by contaminating their syringes.

The technician, David M. Kwiatkowski, 34, pleaded guilty in August to 16 federal charges, including tampering with a consumer product and obtaining controlled substances through fraud.

Prosecutors said that while he was working as a traveling medical technician in several states -- including New Hampshire, Kansas and Maryland -- Kwiatkowski injected himself with syringes of fentanyl, a powerful painkiller, then filled them with saline and put them back into circulation for patients.

Last summer, thousands of patients were tested for Kwiatkowski's strain of hepatitis C, an infectious disease that can cause the liver disease cirrhosis, which can lead to cancer. The 45 patients -- one of whom died -- who were identified by investigators represent one of the biggest outbreaks of the disease in two decades.

Kwiatkowski also worked for UPMC Presbyterian in Pittsburgh from March to May 2008, but was barred from the hospital facilities after staff accused him of stealing syringes full of fentanyl and morphine. UPMC has said testing of patients showed he did not infect anyone there.

In July of this year, an Allegheny County judge dismissed a lawsuit filed against UPMC Presbyterian and Maxim Healthcare Services, which supplies temporary workers such as cardiac technologists. The dismissed suit accused the two organizations of negligence for failing to report Kwiatkowski's alleged narcotics theft.

Before he was sentenced Monday in federal court in Concord, N.H., Kwiatkowski stood and faced his victims, saying he was very sorry and that his crimes were caused by an addiction to painkillers and alcohol. He told investigators he had been stealing drugs since at least 2003 and swapping syringes since at least 2008.

"There's no excuse for what I've done," he said. "I know the pain and suffering I have caused."

Prosecutors asked for a 40-year sentence. Judge Joseph Laplante said he cut the last year as a reminder that some people have the capacity for mercy and compassion.

"It's important for you to recognize and remember as you spend the next 39 years in prison to focus on the one year you didn't get and try to develop that capacity in yourself," Judge Laplante said.

The victims spoke angrily and tearfully of the pain that Kwiatkowski had inflicted by giving them hepatitis C.

"You handed down to us a potential death sentence," said Linda Ficken, 71.

Kwiatkowski had treated Ms. Ficken at Hays Medical Center in Kansas. She gave one of about 20 victim impact statements delivered during the hearing, which lasted several hours.

Jonathan R. Saxe, an assistant federal public defender who represented Kwiatkowski, argued that his actions were motivated by a serious drug addiction, not by an intent to harm others.

"His conduct was surely monstrous, but he's not a monster," Mr. Saxe said in an interview after the hearing.

"There's no worse place to be a drug addict than in a hospital, where you can gain access to stuff like that," said Mr. Saxe, referring to fentanyl.

John P. Kacavas, the U.S. attorney for New Hampshire, called for more oversight and regulation of medical employees like Kwiatkowski.

"While the conclusion of this prosecution closes the criminal aspect of this case, it has cast a harsh light on the dirty little secret of drug diversion in the medical setting," Mr. Kacavas said at a news conference after the sentencing.

Ms. Ficken said the sentence had given her some closure, but little comfort. She learned two weeks ago that her diagnosis ruled out the possibility of her donating bone marrow to her brother, who has leukemia.

"Now, the next thing is just dealing with the disease itself," Ms. Ficken said after the hearing.

Kwiatkowski was a cardiac technologist in 18 hospitals in seven states before being hired at New Hampshire's Exeter Hospital in 2011. He had moved from job to job despite being fired at least four times over allegations of drug use and theft.

Two of the 16 charges stem from the case of Eleanor Murphy, a Kansas woman who has since died. Authorities say hepatitis C played a contributing role.

"You ultimately gave my mother a death sentence," Ms. Murphy's son, Ronnie, told Kwiatkowski.

Mr. Murphy said he would have preferred a life sentence for Kwiatkowski and didn't understand how he had been able to continue working after his repeated firings.

"His path and my mother's path never should have crossed," he said.

First Published: December 2, 2013, 6:53 p.m.
Updated: December 3, 2013, 4:20 a.m.