History of epidemiology

1. Origin Of Epidemiology.
2. Definitions Of Epidemiology.
3. Objectives Of Epidemiology.
4. Branches Of Epidemiology.
5. Timeline Of Epidemiology.
6. John Graunt- The First Epidemiologist.
7. James Lind And Scurvy.
8. Edward Jenner And Small Pox.
9. Ignaz Semmelweis And Childbed Fever.
10. John Snow And Cholera
11. Conclusion

1. HISTORY OF EPIDEMIOLOGY Presented By: Dr. Imrose Rashid Guide & Mentor: Dr. (Prof.) S.M. Salim Khan

2. CONTENTS 1. Origin Of Epidemiology. 2. Definitions Of Epidemiology. 3. Objectives Of Epidemiology. 4. Branches Of Epidemiology. 5. Timeline Of Epidemiology. 6. John Graunt- The First Epidemiologist. 7. James Lind And Scurvy. 8. Edward Jenner And Small Pox. 9. Ignaz Semmelweis And Childbed Fever. 10. John Snow And Cholera 11. Conclusion

3. ORIGIN OF EPIDEMIOLOGY Epidemiology is derived from the Greek word “epidemic”. “epi” which meaning “on or upon or among”. “demos” which means “the common people”. “logy” which means “study”. “The study of that which falls upon the common people”. Essentials of Epidemiology In Public Health, 3rd Edition

4. DEFINITIONS OF EPIDEMIOLOGY The branch of medical science which treats epidemics. - Parkin,1873 The science of the mass phenomena of infectious diseases. - Frost,1927 The study of disease, any disease, as a mass phenomenon. - Greenwood 1934 The study of the distribution and determinants of disease frequency in man. – MacMahon,1960 Park K. Park’s textbook of Preventive and social Medicine.24th Edition. Jabalpur. Banarasidas Bhanot. 2017:57.

5. The study of the distribution and determinants of health-related states or events in specified populations and the application of this study to control of health problems. – John M. Last,1988 The study of how disease is distributed in populations and the factors that influence or determine this distribution. Epidemiology, Leon Gordis, 5th Edition

6. OBJECTIVES OF EPIDEMIOLOGY To identify etiology or cause of a disease and the relevant risk factors. To determine the extent of disease found in the community. To study the natural history and prognosis of disease. To evaluate preventive and therapeutic measures and modes of health care delivery. To provide the foundation for developing public health policy. Epidemiology, Leon Gordis, 5th Edition

7. BRANCHES OF EPIDEMIOLOGY Infectious Disease Epidemiology. Chronic Disease Epidemiology. Clinical Epidemiology. Serological Epidemiology. Cancer Epidemiology. Genetic Epidemiology Occupational Epidemiology Psychosocial Epidemiology Park K. Park’s textbook of Preventive and social Medicine.24th Edition. Jabalpur. Banarasidas Bhanot. 2017:57.

8. TIMELINE 3 rd Century BC- Greek Word Epidemic. 1662- John Grant became the first epidemiologist, statistician and demographer. 1747- James Lind Conducted first ever clinical trial and concluded that citrus fruits cure scurvy. 1796- Edward Jenner performed first Vaccination. In 1849, John Snow published “The Mode Of Communication Of Cholera” 1850s- Epidemiological Society Of London.

9. 1920s- Winslow and Sedgwick lectured on epidemiology in US. 1927- W.H Frost became the first Professor of Epidemiology in US. 1940s- First modern experimental study on the use of Streptomycin to treat Pulmonary TB by BMRC. 1947- Prototype cohort study “Framingham Heart Study” started. 1950- Richard Doll and Bradford Hill conducted first “case control study” that showed association between smoking and Lung cancer.

10. John Graunt – The First Epidemiologist Born in 1620 in London. Worked in his father’s Draper Company. In 1662, he summarized the bills of mortality for his publication “Natural and Political Observations mentioned in a Following Index and Made upon the Bills of Mortality”. Essentials of Epidemiology In Public Health, 3rd Edition

11. Graunt was the first to estimate; The number of inhabitants. Age structure of the population. Rate of population growth. Patterns of mortality. Survival from birth until death. Essentials of Epidemiology In Public Health, 3rd Edition

12. Graunt made inferences about patterns of mortality and morbidity. “Some diseases affected a similar number of people while others varied considerably over time” “Common causes of death include old age, consumption, small pox, plague and diseases of teeth and worms”. “The mortality rate of men was higher than women”. “Fall was the most unhealthful season”. Essentials of Epidemiology In Public Health, 3rd Edition

13. James Lind And Scurvy Born in Edinburg Scotland in 1716. Scurvy is a disease now known to be caused by a vitamin C deficiency. John Woodall recommended that citrus fruits had an antiscorbutic effect. Essentials of Epidemiology In Public Health, 3rd Edition

14. James Lind proposed that the principal predisposing cause was ‘’ moist air’’ and secondary cause was ‘’diet’’. In 1747, Lind conducted a systematic experiment considered as the first reported controlled, clinical experiments in the history of medicine. He divided 12 scorbutic sailors into 6 groups of 2. Group I - Cider daily. Group II - Elixir of vitriol (sulfuric acid). Group III - Vinegar. Group IV - Seawater. Group V – Two Oranges and one lemon. Group VI - Barley water. Essentials of Epidemiology In Public Health, 3rd Edition

15. After 4 weeks Lind reported that oranges and lemons were the most effectual remedies for scurvy. J. Lind proposed that lemon and orange juice be carried onboard.  The British Navy took 40 years to adopt Lind’s recommendations. In 1753, he published ” A treatise of the scurvy”. In 1768, Lind wrote the Essay on “Diseases Incidental to Europeans in Hot Climates, with the Method of Preventing their fatal Consequences”. Essentials of Epidemiology In Public Health, 3rd Edition

16. Edward Jenner And Smallpox Edward Jenner (1749-1823) In late 18 th Century, millions of people died from small pox each year. A third of survivors became blind as a result of corneal infections. Those who survived small pox were subsequently immune to the disease. Consequently variolation became a common preventive practice. Many variolated individuals died from small pox or infected others. Epidemiology, Leon Gordis, 5th Edition

17. E. Jenner observed that dairy maids developed a mild disease called cowpox. Small pox did not appear to develop in these young women. 1768 E. Jenner heard a claim from a dairy maid “I can’t take the smallpox for I have already had cowpox”. Jenner became convinced that cowpox could protect against smallpox. Epidemiology, Leon Gordis, 5th Edition

18. E. Jenner decided to test his hypothesis.

19. Edward Jenner performing the first vaccination in 1796. The term vaccination is derived from Latin word “Vacca” which means “ Cow”. Epidemiology, Leon Gordis, 5th Edition

20. Edward Jenner operated purely on observational data that provided him with basis for a preventive intervention. 1967, WHO began international efforts to eradicate small pox using vaccination with vaccinia virus. 1980, WHO certified that small pox had been eradicated. WHO estimated that 350 million new cases had been prevented over a 20 year period. Epidemiology, Leon Gordis, 5th Edition

21. Ignaz Semmelweis And Childbed Fever Born in 1818. Left his Law School to study Medicine. Specialized in Obstetrics. Became interested in a major clinical and public health problem of the day: Childbed Fever AKA Puerperal Fever. 25% mortality rate. Epidemiology, Leon Gordis, 5th Edition

22. Popular theories were; Atmospheric Toxins, Putrid Air or Solar Influence. In 1846, Semmelweis was placed in charge of The First Obstetrical Clinic of the General Hospital in Vienna. Epidemiology, Leon Gordis, 5th Edition

23. Physicians and medical students went directly from autopsies to their patients. Semmelweis Suggested that hands of Physicians and medical students were transmitting disease-causing particles. Jakob Kolletschka died from a infection contracted accidently with a medical students knife. Semmelweis developed and implemented a policy : Hand Washing. Epidemiology, Leon Gordis, 5th Edition

24. Mortality rates dropped from 12.2% to 2.4%, a rate comparable to that seen in the Second Clinic. Epidemiology, Leon Gordis, 5th Edition

25. Failure of medical community to accept his hypothesis: Semmelweis refused to submit reports of his studies to medical Journals. Lack of supporting evidence. Reluctance of Physicians to accept the responsibility of transmitting Childbed Fever. Years later, the major cause of childbed fever was recognized to be a Streptococcal infection. Policy of hand washing was broadly adopted Epidemiology, Leon Gordis, 5th Edition

26. John Snow And Cholera Anesthesiologist who lived in 19 th Century. Interested in epidemiology of Cholera. Snow was finishing up his medical training when the second cholera pandemic hit England in 1832. Doctors thought that bleeding people was the best way to treat it. It wasn’t.  Epidemiology, Leon Gordis, 5th Edition

27. William Far, the Registrar General believed in the “Miasmatic Theory” of disease. Third cholera pandemic was the most deadly one, taking at least 2 million lives. England alone lost 23,000 . In the first week of September 1854, about 600 people living within 850 feet of the Broad Street pump in Soho London died of Cholera. Snow believed that the cholera was transmitted through contaminated water. https://www.pastmedicalhistory.co.uk/john-snow-and-the-1854-cholera-outbreak/

28. The Southwark and Vauxhall Company was taking water from sewage-polluted sections of the Thames river. Lambert Company had shifted its water intake upstream to a less polluted part. J. Snow reasoned that mortality rates from cholera would be lower in the later. He carried out what we call today “shoe-leather epidemiology” and created a dot map to illustrate the cluster of cases around the pump. https://www.pastmedicalhistory.co.uk/john-snow-and-the-1854-cholera-outbreak/

29. Mortality rate from cholera were actually lower in people getting their water from the Lambeth company. https://www.pastmedicalhistory.co.uk/john-snow-and-the-1854-cholera-outbreak/

30. John Snow knew nothing about v. cholerae. The handle of the pump was removed based on Snow’s findings. After the cholera epidemic had subsided, officials replaced the Broad Street pump handle.  In 1849, Snow published his views on the cause and transmission of Cholera in a pamphlet titled “The Mode Of Communication Of Cholera” https://www.pastmedicalhistory.co.uk/john-snow-and-the-1854-cholera-outbreak/ John Snow Memorial

31. Conclusion- Objectives Met S.No SCIENTIST Objective of Epidemiology Met 01. John Graunt To determine the extent of disease found in the community. 02. James Lind To Identify the etiology or cause of a disease. To evaluate preventive and therapeutic measures. 03. Edward Jenner To evaluate preventive measures of a disease. 04. Ignaz Semmelweis To Identify the etiology or cause of a disease. To evaluate preventive measures of a disease. 05. John Snow To Identify the etiology or cause of a disease. To evaluate preventive measures of a disease. To determine the extent of disease found in the community. To provide foundation for developing public health policy.

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