A former cath lab medical technician dubbed the “serial infector” has been indicted by a federal grand jury in connection with a hepatitis C outbreak in New Hampshire and several other states.

David M. Kwiatkowski, a former employee of Exeter Hospital in Exeter, N.H., has been charged with seven counts of tampering with a consumer product and seven counts of obtaining controlled substances by fraud, U.S. Attorney John P. Kacavas announced Nov. 29. More than 30 patients in New Hampshire and elsewhere have been infected with a strain of hepatitis C that matches a strain of the virus carried by Kwiatkowski.

The charges relate to suspected thefts of the controlled substance fentanyl. Kwiatkowsk has been accused of injecting himself with syringes containing the drug and then replacing them with syringes he had previously stolen and filled with saline. The hospital has since revised its process for securing syringes in its cath lab.

According to the indictment, Kwiatkowski was employed for several years as a healthcare worker in Michigan. Beginning in 2007, he became a traveling healthcare technician, employed in various states, including New York, Pennsylvania, Maryland, Arizona, Kansas, Georgia and New Hampshire. The indictment alleges that Kwiatkowski was infected with hepatitis C and that he was aware that he carried the virus since at least June of 2010. He began working at Exeter Hospital in April of 2011.

Kwiatkowski was arrested on July 19 in Massachusetts on charges of tampering with a consumer product and illegally obtaining drugs. He was transported to New Hampshire, where he has remained in custody. He has pleaded not guilty to the original charges.

If convicted on the pending charges, Kwiatkowski faces up to 10 years in prison for each count of tampering with a consumer product and up to four years in prison for each count of obtaining controlled substances by fraud. Each offense also is punishable by a fine of $250,000 and a term of supervised release following any sentence of imprisonment.