A traveling hospital worker accused of stealing drugs and infecting patients with hepatitis C through contaminated syringes pleaded not guilty to the charges in federal court on Monday. 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. Kwiatkowski, who was handcuffed, said only "yes" when asked in court if he understood his rights. His trial was scheduled for the first week of February, although U.S. Attorney John Kacavas said given the complexity of the case, it probably would take place later in the year.