This document discusses concepts of health and disease, determinants of health, dimensions of good health, and concepts of health including biomedical, ecological, psychological, and holistic concepts. It also discusses preventive medicine, levels of prevention including primary, secondary and tertiary, and principles of prevention. Finally, it provides information on cholera including causative agent Vibrio cholerae, epidemiology, modes of transmission, signs and symptoms, diagnosis and evaluation, treatment, prevention and the role of diarrhoeal disease control programs.