Veterinary Epidemiology and Zoonosis

EPIDEMIOLOGY - DEFINITION

Literal Translation

• The word "epidemiology" is derived from Greek
• Epi = upon; Demos = people; Logos = Study = Discussing, is the ‘study of that which is upon the people’.

Definitions

• Study of the patterns of disease under field conditions.
• Is the study of the frequency, distribution and determinants of health and disease in populations.
• Is the study of disease in populations and of factors that determine its occurrence.
• Is the study of health status of the population (Schwabe et al., 1977).
• Nothing more than ecology with a medical and mathematical favour.
• A population analogue to pathogenesis of disease in individuals.
• Epidemiology is the study of how often diseases occur in different groups of people and why.
• The study of disease as a mass phenomenon (Greenwood, 1934).
• The study of ecology of infectious diseases (Gorden, 1963).
• A method of reasoning about disease that deals with biological inferences derived from observations of disease phenomena in population groups (Linlienfeld, 1978).
• Quantitative analysis of circumstances under which disease processes including trauma occur in population groups, the factors affecting their incidence, distribution and host responses and use of this knowledge in prevention and control (Evans, 1979).
• The investigation of diseases, other health related events and production in animal population and making inferences from the investigation in an attempt to improve the health and productivity of populations (Thrushfield, 1986).