Epidemiology is simply defined as the study of the pattern of occurrence and distribution of disease in a defined human or animal population. It is the study of the relationship between the causative agent of a particular disease, host factors, environmental factors, time factors and the occurrence of disease in a defined population. Epidemiology can also be defined as the study of the cause and distribution of a disease within a defined human population. Epidemiology is that field of medical science which is concerned with the relationship of various factors and conditions which determine the frequencies and distributions of an infectious process, a disease, or a physiologic state in a human community.
It also encompasses the study of the occurrence and distribution of infectious diseases in animal populations – especially those diseases that have tremendous negative impact on human population. Epidemiology is the study of the distribution and determinants of health-related states or events in specified populations, and the application of this study to the control of health problems in the affected populations. Epidemiology is a strategy for the study of factors relating to the aetiology, prevention, and control of disease; to promote health; and to efficiently allocate efforts and resources for health promotion, maintenance and medical care in human populations. Epidemiology is a branch of public health.
Public Health is the science of protecting and improving the health of communities through education, promotion of healthy lifestyles, and research for disease and injury prevention. It is an important part of medicine that is mainly geared towards disease control and prevention rather than treatment. Public health encourages environmental and/or personal sanitation, good water distribution for a community and adequate preparation and distribution of food for public consumption – as a panacea to preventing disease outbreak. Public health professionals analyze the effect on health of genetics, personal choice and the environment in order to develop programs that protect the health of people and the community.
Public health is an interdisciplinary field and professionals in many disciplines such as nursing, medicine, veterinary medicine, dentistry, biosciences and pharmacy routinely deal with public health issues. Overall, public health is concerned with protecting the health of the entire populations. These populations can be as small as a local neighborhood, or as big as an entire country. Public health professionals try to prevent problems from happening or re-occurring through implementing educational programs, developing policies, administering services, regulating health systems and some health professions, and conducting research, in contrast to clinical professionals, such as doctors and nurses, who focus primarily on treating individuals after they become sick or injured.
The public health professional prevent disease outbreak; the clinician/physician treat diseases after disease outbreak or illness; and the epidemiologists follow the trend of disease spread in order to contain it. Public health is also a field that is concerned with limiting health disparities and a large part of public health is the fight for health care equity, quality, and accessibility.
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