As used in this part, terms shall have the following meaning: (a)Bactericidal treatment. The application of a method or substance for the destruction of pathogens and other organisms as set forth in § 1240.10 . (b)Communicable diseases. Illnesses due to infectious agents or their toxic products, which may be transmitted from a reservoir to a susceptible host either directly as from an infected person or animal or indirectly through the agency of an intermediate plant or animal host, vector, or the