The first principle of public health practice is defined as the identification of the root cause or causes of all health problems, from the diseased individual to the effects on that individual of family, social, community, national, global, environment and other factors. The second principle is defined as the utilisation of the resources of the community, the nation and the world to effect a lasting and, often, a cheaper solution to health problems. This comprehensively revised and updated edition of the first volume provides a ready source for principles and practice, and more practical advice than the first edition which did not fully cover all the aspects of a comprehensive public health practice. The contributors are all practitioners, and the emphasis throughout is to bring out the principles involved in identifying the root causes of all types of health problems, and discovering practical and innovatory solutions for them in ways best suited to African countries.