This book deals exhaustively with fundamentals of food sciences, entomology, rodentology, ecology, genetics, and health economics. It examines in detail the communicable and non-communicable diseases of public health importance and lays threadbare the means and methods of their control. It describes difficult and demanding topics like statistics, management, planning, demography and pedagogy in a way that helps even the average reader understand them easily and rapidly. The Book gives an account of legislation as applicable to social security, food contamination, marriage, organ transplantation, traffic accidents, etc. It explains individual, family, community, state, national and international action for the control of diseases, and for preventing their spread from country to country. The Book throws light on social evils like delinquency, drug addiction, child labour, and prostitution and sets out the strategy for combating them. Principles of Community Medicine enumerates ways of promoting the health and well being of children, adolescents, senior citizens, pregnant women, slum dwellers and other vulnerable sections of society.