Newspaper headlines from around the world about polio vaccine
tests (13 April 1955)
Public health has been defined as "the science and art of preventing disease”, prolonging life and promoting human health through organized efforts and informed choices of society, organizations, public and private, communities and individuals". Analyzing the health of a population and the threats it faces is the basis for public health. The public can be as small as a handful of people or as large as a village or an entire city; in the case of a pandemic it may encompass several continents. The concept of health takes into account physical, psychological and social well-being. As such, according to the World Health Organization, it is not merely the absence of disease or infirmity.
Public health is an interdisciplinary field. For example, epidemiology, biostatistics and management of health services are all relevant. Other important subfields include environmental health, , behavioral health, health economics, public policy, mental health, health education, occupational safety, gender issues in health, and sexual and reproductive health.
Public health aims to improve the quality of life through prevention and treatment of disease, including mental health. This is done through the surveillance of cases and health indicators, and through the promotion of healthy behaviors. Common public health initiatives include promotion of handwashing and breastfeeding, delivery of vaccinations, suicide prevention, and distribution of condoms to control the spread of sexually transmitted diseases.
Modern public health practice requires multidisciplinary teams of public health workers and professionals. Teams might include epidemiologists, biostatisticians, medical assistants, public health nurses, midwives, medical microbiologists, economists, sociologists, geneticists, data managers, and physicians. Depending on the need, environmental health officers or public health inspectors, bioethicists, and even veterinarians, gender experts, or sexual and reproductive health specialists might be called on.
Access to health care and public health initiatives are difficult challenges in developing countries. Public health infrastructures are still forming in those countries.
The focus of a public health intervention is to prevent and mitigate diseases, injuries and other health conditions through surveillance of cases and the promotion of healthy behaviors, and environments. Many diseases are preventable through simple, nonmedical methods. For example, research has shown that the simple act of handwashing with soap can prevent the spread of many contagious diseases. In other cases, treating a disease or controlling a pathogen can be vital to preventing its spread to others, either during an outbreak of infectious disease or through contamination of food or water supplies. Public health communications programs, vaccination programs and distribution of condoms are examples of common preventive public health measures. Measures such as these have contributed greatly to the health of populations and increases in life expectancy.
Public health plays an important role in disease prevention efforts in both the developing world and in developed countries through local health systems and non-governmental organizations. The World Health Organization (WHO) is the international agency that coordinates and acts on global public health issues. Most countries have their own governmental public health agency, often called the ministry of health, with responsibility for domestic health issues.
In the United States, state and local health departments are on the front line of public health initiatives. In addition to their national duties, the United States Public Health Service (PHS), led by the Surgeon General of the United States, and the Centers for Disease Control and Prevention, headquartered in Atlanta, are also involved with international health activities.
In Canada, the Public Health Agency of Canada is the national agency responsible for public health, emergency preparedness and response, and infectious and chronic disease control and prevention. The Public health system in India is managed by the Ministry of Health & Family Welfare of the government of India with state-owned health care facilities.