Expanding the concept of public health

Ancient societies recognized the need for sanitation, food safety, workers' health, and medical care to protect against disease and promote well-being and civic prosperity. New energies and knowledge since the 18th century have produced landmark discoveries, such as the prevention of scurvy and vaccination against smallpox. The biological germ theory and competing miasma theory each proved effective in developing modern public health through sanitation and the control of infectious diseases. Noncommunicable diseases became the leading causes of mortality in the 20th century. In the latter part of the century, their incidence declined in response to innovative preventive care of health risk factors, reductions in smoking, and increased attention to hypertension, obesity, physical inactivity, unhealthful diets, and diabetes mellitus. Health promotion proved effective to modern public health in tackling disease origins, individual behavior, and hygienic, social, and economic conditions. The global burden of disease patterns is changing with new infectious challenges and the prominence of noncommunicable diseases, aging, rising costs, lack of universal health coverage, inequities, inadequate prevention, and new health technology and providers. Continuous development of new prevention and treatment methods continues to revolutionize public health. Nonetheless, pandemics such as HIV/AIDS, severe acute respiratory syndrome, and COVID-19 have constituted major public health pandemic disasters in the current era. The COVID-19 pandemic reinforced the idea of One Health, in which animal sources of disease, vectors, and the environment are vital factors in global human health. Existing and new human health challenges are being addressed by public health policy that is evolving into a dynamic New Public Health.