© 2010 Jones and Bartlett Publishers, LLC

Historical Developments in Epidemiology Chapter 2

© 2010 Jones and Bartlett Publishers, LLC  Describe important historical events in the field of epidemiology  List several individuals who contributed to and helped shape the field of epidemiology  Recognize the application of certain epidemiologic concepts, principles, and study design methods Objectives

© 2010 Jones and Bartlett Publishers, LLC  Contributors in the history of epidemiology Sought to understand and explain illness, injury, and death from an observational scientific perspective Sought to provide information for the prevention and control of health-related states and events in the population Introduction

© 2010 Jones and Bartlett Publishers, LLC  A physician who became known as the father of medicine and the first epidemiologist  His three books; Epidemic I, Epidemic III, and On Airs, Waters and Places; attempted to describe disease from a rational basis instead of a supernatural explanation Hippocrates, the first epidemiologist (460 B.C. to 377 B.C.)

© 2010 Jones and Bartlett Publishers, LLC  He observed that different diseases occurred in different locations  He noted that malaria and yellow fever most commonly occurred in swampy areas  He also introduced terms like epidemic and endemic Hippocrates, the first epidemiologist (460 B.C. to 377 B.C.)

© 2010 Jones and Bartlett Publishers, LLC  Believed that observation should drive the study of the course of disease  Described and distinguished different diseases including some psychological maladies  Advanced useful treatments and remedies including exercise, fresh air, and a healthy diet, which other physicians rejected at the time Disease observations of Thomas Sydenham ( )

© 2010 Jones and Bartlett Publishers, LLC  Applied experimental methods to identify that eating citrus fruits were effective remedies for scurvy among sailors at sea (H.M.S. Salisbury, 1747)  Also made clinical observations, used experimental design, asked classical epidemiological questions, observed the population changes and its effect on disease, and considered sources of causation, including place, time, and season James Lind ( ))

© 2010 Jones and Bartlett Publishers, LLC  A farmer/dairyman in the mid-1700s, noticed his milkmaids never got smallpox, but did get cowpox  Exposed his wife and children to cowpox  Variolation – Chinese had observed for centuries that getting a weaker strain of smallpox was protective against a stronger strain of the disease Benjamin Jesty

© 2010 Jones and Bartlett Publishers, LLC  Jenner attempted to give a dairymaid, exposed to a mild case of cowpox in her youth, a case of cowpox by cutting her arm and rubbing some of the infectious “grease” into the wound. She did not get ill.  He subsequently invented a vaccination for smallpox Edward Jenner ( )

© 2010 Jones and Bartlett Publishers, LLC  In 1846 Semmelweis observed high level of deaths in mothers with childbed fever  Unclean hands with putrefied cadaver material on student doctors’ hands were used to conduct the routine daily pelvic exams, and the practice was never questioned  Identified the importance of washing hands to prevent the spread of disease Ignaz Semmelweis ( )

© 2010 Jones and Bartlett Publishers, LLC  Provides an example of both a descriptive and analytic epidemiologic study John Snow ( )

© 2010 Jones and Bartlett Publishers, LLC  Steps of descriptive study Determined area persons with cholera lived and worked Mapped distribution of cases on a spot map Looked for clustering of cases around water pumps Identified water supply (pump) for those with cholera John Snow studied an epidemic of cholera that developed in 1848 in the Golden Square of London

© 2010 Jones and Bartlett Publishers, LLC  Lambeth Co. – Water intake above London on the Thames River  Southwark and Vauxhall Co. – Water intake below London on the Thames River Larger outbreak of cholera in London in 1854 Two water suppliers

© 2010 Jones and Bartlett Publishers, LLC Vauxhall & SouthwarkLambeth Population98,862154,615 Cholera deaths Death rate Per 1000 Rate ratio = 4.2/0.5 = 8.4 Mortality from cholera in London related to the water supply of individual houses in districts served by both companies, July0-August 26, 1854

© 2010 Jones and Bartlett Publishers, LLC  Identified the causes of rabies  Investigated how sheep and humans contracted the bacteria called anthrax  Showed that bacteria could cause disease  Discovered a vaccine for anthrax Louis Pasteur (1822–1895)

© 2010 Jones and Bartlett Publishers, LLC  With Pasteur, established the germ theory of disease  Used photography to take the first pictures of microbes in order to show the world that microorganisms do in fact exist and that they are what cause diseases  Koch showed that anthrax was transmissible and reproducible in experimental animals (mice)  Identified the spore stage of the growth cycle of microorganisms  Demonstrated that the anthrax bacillus was the only organism that caused anthrax in a susceptible animal Robert Koch ( )

© 2010 Jones and Bartlett Publishers, LLC  Using the “Bills of Mortality” in London, he systematically recorded age, sex, who died, of what, where they died, and when  Recorded how many persons per year died of what kind of event or disease  Developed and calculated life tables and life expectancy  Divided deaths into two types of causes Acute (struck suddenly – e.g., cholera) Chronic (lasted over a long period of time – e.g., emphysema) John Graunt ( )

© 2010 Jones and Bartlett Publishers, LLC ChristenedBuried Males 4,994Males 4,932 Females 4,590Females 4,603 In All 9,584 In All 9,535 Increased in the Burials in the 122 Parishes, and at the Pesthouse this year – 993 Decreased of the Plagues in the 122 Parishes, and at the Pesthouses this year – 266 Diseases and casualties in London, 1632

© 2010 Jones and Bartlett Publishers, LLC  Extended the use of vital statistics and organized and developed a modern vital statistics system, much of which is still in use today  Promoted the idea that some diseases, especially chronic diseases, may have a multifactorial etiology William Farr ( )

© 2010 Jones and Bartlett Publishers, LLC  Observed that disease among workers arose from two causes: Harmful character of the materials that workers handled as the materials often emitted noxious vapors and very fine particles which could be inhaled Certain violent and irregular motions and unnatural postures imposed upon the body while doing work Bernardino Ramazzini ( )

© 2010 Jones and Bartlett Publishers, LLC  Nurse  Helped create changes in hygiene and overall treatment of patients Florence Nightingale

© 2010 Jones and Bartlett Publishers, LLC  Chronic carrier of typhoid fever, causing over 250 cases  Personally had no symptoms of the disease  1907 to 1910, confined by health officials until released through legal action taken by her  Taught public health officials and epidemiologists the importance of keeping track of carriers Mary Mallon – Irish cook (known as Typhoid Mary)

© 2010 Jones and Bartlett Publishers, LLC  In 1887 eradicated beriberi from the Japanese Navy by adding vegetables, meat, and fish to their diet, which was mostly rice  Kwashiorkor Disease T.K. Takaki

© 2010 Jones and Bartlett Publishers, LLC  In 1850, published the first report on sanitation and public health problems  Shattuck’s report set forth the importance of establishing state and local boards of health and recommended an organized effort to collect and analyze vital statistics  Recommended the exchange of health information, sanitary inspections, research on tuberculosis, and the teaching of sanitation and prevention in medical schools Lemuel Shattuck ( )

© 2010 Jones and Bartlett Publishers, LLC  Suggested that morbidity statistics be classified into five general groups in order to be of value 1. Reports of communicable diseases 2. Hospital and clinical records 3. Insurance and industrial establishment of school illness records 4. Illness surveys 5. Records of the incidence of illness in a population continuously or frequently observed Edgar Sydenstricker ( )

© 2010 Jones and Bartlett Publishers, LLC  In 1948 the Framingham, Massachusetts, cardiovascular disease study was launched  Prospective cohort study design The Framingham Study

© 2010 Jones and Bartlett Publishers, LLC  Case-control studies assessing the association between smoking and lung cancer Wynder and Graham in the US (1950) Doll and Hill in Great Britian (1950)  Cohort study Doll and Hill (1951) The epidemiology of smoking and lung cancer