2 The public health approach

The term public health refers to the ‘science and art of preventing disease, prolonging life, and promoting health’ (Winslow, 1920) and encompasses everything affecting the health of a population as a whole, rather than the individuals of which it is composed. A population may be all members of a nation or geographical region, or a defined group, for example all children under five years of age, all members of a minority ethnic group, or all women during the potential childbearing years. Public health is also concerned with non-communicable diseases, for example cancers, cardiovascular diseases and diabetes.

Here we focus specifically on the public health approach to infectious disease. This encompasses four broad areas of work:

• surveillance, monitoring and reporting of disease outbreaks and analysis of epidemiological data to shed light on the underlying causes, and inform actions to bring outbreaks under control
• direct intervention to prevent infection, e.g. through vaccination, reducing environmental sources of pathogens, or isolation and treatment of infected individuals
• education to promote behaviour change that reduces the risk of infection, or reduces the impact of an infectious disease outbreak
• organising and supporting community action to promote and sustain a healthier population and local environment and to coordinate community responses to outbreaks of infectious disease.

All of these areas are addressed in the rest of this course after a very brief review of the origins of the public health movement.