ABSTRACT
Originally, the term ‘epidemiology’ meant ‘the study of epidemics’, but the techniques that were originally used in the study and control of epidemics have also been usefully applied in the study of other types of diseases including noncommunicable diseases and accidents. In its modern usage, the term epidemiology refers to the study of the distribution of disease in human populations, against the background of their total environment. It includes a study of the patterns of disease as well as a search for the determinants of disease. It exploits the technologies from other disciplines – microbiology, parasitology, social sciences, etc. in analysing the frequency, distribution and determinants of health and disease in populations. New advances in genetics and molecular biology have stimulated the development of molecular epidemiology; it investigates the contributions of genetic and environmental risk factors that are identified at the molecular level in the aetiology and distribution of health and disease in groups and populations.
