PRINCIPLES OF EPIDEMIOLOGY AND DISEASE SURVEILLANCE HISTORICAL BACKGROUND

PRINCIPLES OF EPIDEMIOLOGY AND DISEASE SURVEILLANCE: HISTORICAL BACKGROUND TUNRAYO OLUWADARE DEPARTMENT OF COMMUNITY MEDICINE

EVOLUTIONARY PROCESS It has grown from PURE OBSERVATIONS AND ADVICES (Hippocrates) COUNTING OF CASES AND ANALYSIS (John Graunt & William Farr) NATURAL EXPERIMENTS (John Snow) TRUE EXPERIMENTS Lind, Jenner, Fletcher, Doll &Hill & Other epidemiologists in the last two century

GROWTH FROM 17 TH -19 TH CENTURY PERIOD EPIDEMIOLOGIST CONTRIBUTION 1600 AD JOHN GRAUNT LONDON BILLS OF MORTALITY ANALYSIS 1747 JAMES LIND CITRUS FRUITS TO CURE SCURVY IN SAILORS 1796 EDWARD JENNER TRIAL WITH COWPOX VACCINE GROWTH 17 TH -19 TH CENTURIES 1880 W. H. FROST EXPLAINED INTERPLAY OF FACTORS CAUSING EPIDEMICS 1889 WILLIAM FARR ANALYSIS OF VITAL STATISTICS & EFFECTS OF IMPRISONMENT IN PRISONERS 1849 JOHN SNOW NATURAL EXPERIMENT ON LONDON CHOLERA 1881 FINLAY MOSQUITO BORNE NATURE OF YELLOW FEVER 1900 BRADFORD HILL. A CONCEPT OF RANDOMIZATION & SMOKING AND LUNG CANCER EXPERIMENTS.

Historical development • Hippocrates • 400 BC he explained disease occurrence from a rational rather than a supernatural viewpoint • He wrote an essay titled “ On Airs, Waters, and Places” • Environmental and host factors might influence the development of disease.

Historical development contd. • Hippocrates contd. • He advised that factors causing disease be searched • Air (hot &cold winds) • Water (marshy, soft, hard, from rocky soil, unfit for cooking) • Places (naked without vegetation, deficient in water, well watered, elevated and cold) • Personal habits

Historical development contd. • John Graunt ( 1600 AD) • A London tradesman and founding member of the Royal Society of London • He became the first epidemiologist, statistician, and demographer • Summarized the Bills of Mortality for his 1662 publication. • This publication was the first to quantify patterns of birth, death, and disease occurrence, noting disparities between males and females, high infant mortality, urban/rural differences, and seasonal

Historical development contd. • John Graunt ( 1600 AD) • He counted the mortality rates for 37 years in London from the Bills of mortality and found • . Constancy in the ratio from male to female in births and deaths. • Age specific mortality is higher among males than in females. • Seasonal fluctuations in deaths from various causes.

Historical development contd. • John Graunt ( 1600 AD) • Measured the ebb and flow of various diseases and the host factors. • Suggested quantitative methods to test the hypothesis of this variations.

Historical development contd. • James Lind (1716 - 1794) • A Scottish Naval Surgeon, conducted a true experiment on his 12 soldiers suffering from Scurvy • Vinegar • Mixture of nutmeg, garlic, mustard and tamarind in barley water • Elixir vitrol • Seawater • Cider • Two oranges and one lemon

Historical development contd. • Edward Jenner (1796) • Was an English Physician • The first person to immunize against smallpox with cowpox vaccine • His discovery paved way for preventive medicine and epidemiology.

Historical development contd. • William Farr (1807 -1883) • He is considered one of the founders of modern epidemiology • The father of modern vital statistics and surveillance • Farr was the compiler of Statistical Abstracts for the General Registry Office in Great Britain from 1839 through 1880. • He analyzed the vital statistics for 40 years and made valuable observations with regard to then health situation and recommended their application for public health improvement.

Historical development contd. • William Farr (1807 -1883) contd. • He found high mortality in certain occupations like miners. • He studied the health of prisoners and found that while 8 only died due to executions, 52 died of imprisonment. • He also found that fluctuations in marriage rates depend upon price of bread, cholera, population movements and person’s monetary value.

Historical development contd. • William Farr (1807 -1883) contd. • His findings paved the way for proper health planning and policies and thus fostered epidemiology and occupational health and safety.

Historical development contd. • John Snow (1813 -1858) • He was a Physician for Queen Victoria and a a great epidemiologist • He is considered the father of” field epidemiology” • Controlled cholera in London • He was able to prove his hypothesis by means of natural experiment that contaminated water is the vehicle for cholera spread.

Historical development contd. • Fletcher (1905) • Fletcher studied Beriberi that occurred in lunatics in mental asylum in Kuala Lumpur (Malaysia) and proved that it is due to nutritional deficiency. • He used parboiled rice and Siamese rice for his true experiment.

Historical development contd. • Goldberger Joseph (1915) • He proved that Pellagra is not an infectious disease as it was thought earlier, but a nutritional deficiency state.

Historical development contd. • Modern epidemiology • In the 1930 s and 40 s epidemiologists extended their methods to non infectious diseases. • The study of Richard Doll and Bradford Hill • In 1980 s epidemiologists extended the study to injuries and violence.

Historical development contd. • Modern epidemiology contd. • In 1990 s it was extended to related of molecular and genetic epidemiology. • Today, health workers throughout the world accept and use epidemiology, regularly to characterize the health of the communities and to solve day-day problems, large and small.

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