Human resources are central to all public health systems and a considerable share of resources allocated to public health goes towards them (1).

 Health workers in adequate numbers, in the proper places, and properly trained, motivated and supported are the backbone of an effective, equitable, and efficient public health care system (2). Establishing and sustaining an effective public health workforce in India to achieve national health goals under MDGs will require sound policy to be translated though an effective strategy and committed implementation with an inbuilt mechanism of monitoring and periodic evaluation.

  Several national level policy, plan and review documents outlined insufficient numbers of doctors in government health care service provision throughout the country, both general medical officers and specialists, and the issue has been a matter of government concern for some time (3, 4, 5, 6). It has again become the subject matter of discussion with significant government efforts to scale-up health care delivery through the National Rural Health Mission. The Government of India has increased its financial allocation to health through the NRHM and the new Indian Public Health Standard (IPHS) – norms for health facilities that, to be achieved, will require many more doctors to enter public health service (7).  

In its popular understanding public health continues to remain unclear. Health and public health gets mixed up and become inseparable. There is considerable confusion about public health as a discipline, which is considered distinct from but complementary to clinical medicine (8).  The public health workforce is characterized by its diversity and its complexity and includes people from a wide range of occupational backgrounds.  Among them are public health physicians, nurses, nutritionists, sanitarians, environmental heal specialists, policy analysts, epidemiologists, demographers, social and behavioral scientists, health promoters, social workers and community health workers, biostatisticians etc. To be very specific Public health is a composite discipline. Public health draws its strength from a number of academic disciplines,  including anthropology, history, economics, sociology and political science, as well as epidemiology and statistics  (9). The public health workforce is trained in a variety of institutional settings.  It adds to the complexity of understanding of public health workforce in the country. Before we define public health workforce more precisely let us make an attempt to define public health. Public health has often been defined as a science, which deals with the determinants of health at the population level, while clinical medicine deals with diseases and their remedies at the level of the individual patient (8).

If we look at public health legislations, though there are several legislative tools in the country it does not have any composite public health act covering the entire country and defining public health. Tamil Nadu has a public health act (10), which has defined public health as: 

“Public Health is the science and the art of preventing disease, prolonging life and promoting physical health and efficiency through organized state effort, by the sanitation of the environment, the control of infections, the education of the  individual in principles of personal hygiene, the organization of medical and nursing service and the early diagnosis and preventive treatment of disease and the development of the social machinery which will ensure to every individual a standard of living adequate for the maintenance of health : It is the organizing of these benefits in such a fashion as to enable every citizen to realize his birthright of health and longevity”.  

The accepted definition in the United States, by the  Institute of Medicine, is that \"the mission of public health is to fulfill society\'s interests in assuring conditions in which people can be healthy\" while the accepted definition in the United Kingdom is: \"the art and science of preventing disease, promoting health, and prolonging life through the organized efforts of society\" (11).

In the paper by WHO, Regional Office for South East Asia (12) entitled “Profiling Public Health Workforce in Countries of the South-East Asia Region” the following definition of Public Health has been provided. “Public health can be defined as “the collective action for sustained population wide improvement in health”. Its mission is to improve the health of populations and reduce health inequalities. This encompasses systematic efforts to promote physical and mental health and to prevent disease, injury and disability. This task has been made increasingly complex by developments such as globalization, scientific and technological advances, and changing demographics. Both globally and regionally, this has led to a serious examination of the public health workforce and on ways to ensure that it is prepared to address the many challenges it faces”. 

According to the Public Health Foundation of India, “Public health has often been defined as a science dealing with the determinants and defence of health at the population level, while clinical medicine deals with multiple maladies and their remedies at the level of an individual patient. Public health aims to understand and influence the social, cultural and economic determinants of health as well as to study and structure health systems as efficient channels for health services delivery. Public health is thus a discipline built on the academic tradition of inquiry involving research, teaching and professional practice to prevent disease and promote health in populations” (13).