CONCORD, N.H. — A traveling hospital worker accused of stealing drugs and infecting patients with hepatitis C through contaminated syringes has pleaded not guilty to the charges in New Hampshire federal court.

David Kwiatkowski, whom prosecutors describe as a “serial infector,” was indicted last week on multiple charges of tampering with a consumer product and illegally obtaining drugs.

Search photos available for purchase: Photo Store →

Kwiatkowski only said “yes” when asked in court Monday if he understood his rights. Trial was set for the first week of February.

Until May, Kwiatkowski worked as a cardiac technologist at Exeter Hospital, where 32 patients were diagnosed with the same strain of hepatitis C he carries. Before that, he worked in 18 hospitals in seven states. Patients in Arizona, Georgia, Kansas, Maryland, Michigan, New York and Pennsylvania have since been tested for hepatitis C.