This document discusses various infectious diseases including their reservoirs, transmission cycles, causative agents, vectors, and periods of communicability and isolation. It covers zoonotic diseases transmitted from animals to humans like rabies, brucellosis, and hydatid disease. Rodent-associated diseases like plague, leptospirosis, and murine typhus are also mentioned. Rickettsial diseases transmitted by mites and ticks such as scrub typhus, Rocky Mountain spotted fever, and epidemic typhus are described along with their agents and vectors. Periods of communicability and isolation for various diseases are provided. Common features of gastrointestinal infections and chemoprophylaxis for selected diseases are briefly outlined.