History of Epidemiology| Historical development of Epidemiology

What is Epidemiology?

Epidemiology is defined as the “Quantitative study of distribution and determinants of health related states and events in a specified population and application of this study to control of health problems.”(John.M Last,2006).

Historical development of Epidemiology

Although epidemiology as a discipline has blossomed since Second World War, epidemiologic thinking has been traced from John Graunt, James Lind, William Farr, John Snow and others. The contributions of some of those early and more recent thinkers are described below;

1) Circa 400 B.C

First expressed over 2000 years ago by Hippocrates. Hippocrates explained the occurrences of disease from rational causes instead of supernatural force .In his essay entitled ‘On air,water and Place ‘ suggested that environment and host factors have influences in development of diseases.

2) John Graunt,1662

• John Graunt, who studied the mortality statistics ,published mortality data in 1662.
• He quantified the pattern of birth, death, and disease occurrences, infant mortality ,urban/ rural and seasonal variation of these events.

3) 1716-1794

• In 1747, James Lind carried out experiments to discover the cause of scurvy.
• Lind selected 12 men from the ship suffering from scurvy and divided them into six pairs, giving each group different additions to their diet
• Some were given cider, others seawater, others a mixture of garlic mustard and horseradish.
• Another group of two were given spoon full of vinegar and
• The last groups with oranges and lemon
• Scurvy disappeared almost completely on the supply of lemon juice to the ships.

4) 1800

• William Farr build upon the Graunt’s works by systematically collecting and analyzing and evaluation of data on vital statistics and disease classification.
• Farr considered the father of modern vital statistics and survelliance ,developed many of the basic practices used today in vital statistics and disease classification.
• He concentrated his efforts on collecting vital statistics, assembling and evaluating those data, and reporting to responsible health authorities and general public.

5) 1854

• Anaesthologist John Snow conducted several classical investigation in London around mid 1800s,, probably twenty years before the development of microscope.
• He performed epidemiological investigation of cholera outbreak ( 1848- 1854) to discover the cause of disease and to prevent recurrence.
• He sketched the spot map and pointed out the sources of drinking water to illustrate the outbreak and the area affected by cholera epidemic.