Historical Developments in Epidemiology

1
Chapter 2

• Historical Developments in Epidemiology

2
Objectives

• 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

3
Introduction

• 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

4
Hippocrates, the first epidemiologist (460 B.C.
to 377 B.C.)

• 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

5
Hippocrates, the first epidemiologist (460 B.C.
to 377 B.C.)

• 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

6
Disease observations of Thomas Sydenham
(1624-1689)

• 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

7
James Lind (1716-1794))

• 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

8
Benjamin Jesty

• 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

9
Edward Jenner (1749-1823)

• 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

10
Ignaz Semmelweis (1818-1865)

• 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

11
John Snow (1813-1858)

• Provides an example
• of both a descriptive
• and analytic epidemiologic study

12
John Snow studied an epidemic of cholera that
developed in 1848 in the Golden Square of London

• 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
  choldera

13
Larger outbreak of cholera in London in 1854
Two water suppliers

• Lambeth Co. Water intake above London on the
  Thames River
• Southwark and Vauxhall Co. Water intake below
  London on the Thames River

14
Mortality from cholera in London related to the
water supply of individual houses in districts
served by both companies, July0-August 26, 1854

• Vauxhall Southwark Lambeth
• Population 98,862 154,615
• Cholera deaths 419 80
• Death rate 4.2 0.5
• Per 1000
• Rate ratio 4.2/0.5 8.4

15
Louis Pasteur (18221895)

• 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

16
Robert Koch (1843-1910)

• 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

17
John Graunt (1620-1674)

• 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)

18
Diseases and casualties in London, 1632

• Christened Buried
• Males 4,994 Males 4,932
• Females 4,590 Females 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

19
William Farr (1807-1883)

• 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

20
Bernardino Ramazzini (1633-1714)

• 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

21
Mary Mallon Irish cook (known as Typhoid Mary)

• 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

22
T.K. Takaki

• In 1887 eradicated beriberi from the Japanese
  Navy by adding vegetables, meat, and fish to
  their diet, which was mostly rice

23
Lemuel Shattuck (1793-1859)

• In 1850, published the first report on sanitation
  and public health problems
• Shattucks 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

24
Edgar Sydenstricker (1881-1936)

• Suggested that morbidity statistics be classified
  into five general groups in order to be of value
• Reports of communicable diseases
• Hospital and clinical records
• Insurance and industrial establishment of school
  illness records
• Illness surveys
• Records of the incidence of illness in a
  population continuously or frequently observed

25
The Framingham Study

• In 1948 the Framingham, Massachusetts,
  cardiovascular disease study was launched
• Prospective cohort study design

26
The epidemiology of smoking and lung cancer

• 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)