While the official cause of the hepatitis C outbreak at Exeter Hospital has not been pinned down, officials say the most likely hypothesis is that a worker associated with the hospital’s cardiac catheterization lab used equipment as part of a drug habit and then reused them with patients to hide their misuse. A report issued last month by the Centers for Disease Control detailed the complicated steps needed to confirm that a hepatitis C outbreak was related to a technician's actions. One possible response to such problems is random drug testing of certain healthcare workers, an idea that has long been controversial and is not part of standard medical procedures.