Dr. A. K. AVASARALA MBBS, M.D.

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ORIGIN, GROWTH
DEVELOPMENT OF EPIDEMIOLOGY

• Dr. A. K. AVASARALA MBBS, M.D.
• PROFESSOR HEAD DEPT OF COMMUNITY MEDICINE
  EPIDEMIOLOGY
• PRATHIMA INSTITUTE OF MEDICAL SCIENCES,
  KARIMNAGAR, A.P.
• INDIA 91505417
• avasarala_at_yahoo.com

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EPIDEMIOLOGY TREE
DEVELOPMENT 1915 till to date
GROWTH 1600-1905 (GRAUNT TO FLETCHER)

AD
ORIGIN
(HIPPOCRATIC TIMES ) 463 BC
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EPIDEMIOLOGY TREE

• Has taken roots in
• Hippocratic times
• Started growing in 17th century
• Lull in next two centuries due
• to microbial era domination
• Developed and blossomed in
• 20th 21st centuries.

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ORIGIN

• SLIDES 4 TO 8

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ORIGIN 2400 YEARS AGO

• HIPPOCRATES planted the seed the tree of
  epidemiology has taken its roots in 463 BC,
  hence it is very old.
• His treatise on the role of environment in
  causing the disease Airs,Waters and Places is
  the first vivid epidemiological description
• Hence paradoxically, Epidemiology , is both
  very old and very young science as it has
  mostly developed recently.

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HIPPOCRATES , THE FIRST EPIDEMIOLOGIST
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AIRS,WATERS PLACESOF HIPPOCRATES
He stated in his famous treatise On Airs,
Waters, Places, that...
 Whoever wishes to
investigate medicine properly should proceed
thus in the first place to consider the seasons
of the year, and what effects each of them
produces. Then the winds, the hot and the cold,
especially such as are common to all countries
and then such as are peculiar to each locality.
In the same manner. When one comes into a city to
which he is a stranger, he should consider its
situation, how it lies as to the winds and the
rising of the sun for its influence is not the
same whether it lies to the north or the south,
to the rising or to the setting sun.
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HIS KEEN OBSERVATION APPLIED COMMONSENSE
HE ADVISED to search for factors causing disease
in 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 (drinking,
excessive eating, fond of exercise,
and labor)
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GROWTH

• SLIDES 9 TO 24

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GROWTH NOURISHED BY GRAUNT, SNOW, LIND,
FLETCER, DOLL, HILL, GOLDBERGER, ARR, JENNERWITH
THEIR

• PHILOSOPHICAL GENIUS
• KEEN OBSERVATION
• COUNTING OF CASES
• EXPLOITING THE NATURAL DISTURBANCES
• OF HEALTH DISEASE
• APPLIED COMMONSENSE, CREATIVE THINKING,
• GENERALIZATION CONCEPT
• SCIENTIFIC REASONING VALIDITY
• COMPARABILITY AND ACCOUNTABILITY

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EVOLUTIONARY PROCESS

• IT HAS GROWN FROM
• PURE OBSERVATIONS ADVICES FROM HIPPOCRATES TO
• COUNTING OF CASES ANALYSIS BY GRAUNT WILLIAM
  FARR
• 
  
• NATURAL EXPERIMENTS BY JOHN SNOW
• TRUE EXPERIMENTS
• BY LIND, JENNER, FLETCHER, DOLL HILL
  OTHER EPIDEMIOLOGISTS IN THE LAST TWO CENTURIES

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FIVE PHAGES OF GROWTH

• First phage
• Investigation of specific diseases- efforts were
  concentrated to investigate cholera, pellagra,
  scurvy, beri beri, lung cancers ( e.g. Snows
  cholera, Fletchers beri beri, Linds scurvy
  experiments)
• Second phage (turning point)
• Introduction of randomization ,blinding and
  controlling to eliminate bias and enhance the
  quality of methods of investigation and make them
  systematic without errors.
  Credit of stimulus goes to DOLL HILL
  experiments at this stage.

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

• John Graunt in 17th century counted the
  mortality rates for 37 years in London from the
  Bills of mortality and found
• 1) constancy in the ratio from male to female in
  births and deaths.
• 2) age specific mortality is higher among males
  than in females.
• 3) seasonal fluctuations in deaths from various
  causes.
• 4) measured the ebb and flow of various diseases
  and the host factors.
• 5) suggested quantitative methods to test the
  hypothesis of this variations.

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JAMES LINDS CONTRIBUTION (1747)
JAMES LIND (1747) of 18 th century made notable
contributions to the growth of epidemiology.
James Lind, a naval surgeon, conducted a true
experiment on his 12 soldiers suffering from
scurvy. He made them into six pairs and
supplemented each pairs diet with 1) vinegar,
2) mixture of nutmeg, garlic, mustard
and tamarind in barley water, 3) elixir
vitriol, 4) sea water, 5) cider, and 6) two
oranges and one lemon for six days. Limeys, the
pair which has taken oranges and lemons showed
improvement from Scurvy and it was a proved that
fresh fruits relieved scurvy. This is a true
experiment he carried out where in he
deliberately modified the diets to get the
desired information.
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EDWARD JENNERS CONTRIBUTION (1796)

• EDWARD JENNER(1796), an English Physician, was
  the first person to immunize against smallpox
  with cowpox vaccine. He accidentally found that
  milkmaids infected with cowpox were immune to
  smallpox. Then he inoculated a boy of 10 years
  of age with mild live cowpox vaccine to immunize
  against smallpox and over the succeeding two
  years he successfully inoculated 22 more persons
  thus paved the way for preventive medicine and
  epidemiology.

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WILLIAM FARRS CONTRIBUTION (1889)

• William Farr, a physician of the 19th century,
  working as the first in Registrar General
  office of England Wales, analyzed the vital
  statistics for 40 years and made valuable
  observations with regard to the then health
  situation and recommended their application for
  public health improvement. He found high
  mortality in certain occupations like miners.
  He studied the health of prisoners and found,
  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 persons
  monetary value. His findings paved the way for
  proper health planning and policies and thus
  fostered epidemiology.

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JOHN SNOWS CONTRIBUTION (1849)

• John Snow (1849) is a physician for Queen
  Victoria and great epidemiologist. He is a
  philosophical genius because he could control
  cholera in London even before the causative
  organism was discovered and found out how
  cholera spreads. His genius showed in his
  meticulous and scientific way of conducting the
  natural experiment to prove his hypothesis that
  contaminated water is the vehicle for the
  cholera spread. He thoughtfully considered all
  other causes that may confound his hypothesis
  and wisely neutralized them. He had seen that
  no difference whatever existed, either in the
  houses or the people receiving water supply of
  two water companies, or in any physical
  conditions with which they are surrendered.

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SNOW S WORDS ABOUT HIS EXPERIMENT
The intermixing of the water supply of the
Southwark and Vauxhall Company with that of the
Lamberth Company, over an extensive part of
London, admitted of the subject being sifted in
such a way as to yield the most incontrovertible
proof on one side or the other. In the sub-
districts enumerated in the above table Table in
this chapter as being supplied by both
Companies, the mixing of the supply is of the
most intimate kind. The pipes of each Company go
down all the streets, and into nearly all the
courts and alleys. A few houses are supplied by
one Company and a few by the other, according to
the decision of the owner or occupier at that
time when the Water Companies were in active
competition.
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GREATNESS OF SNOWS EXPERIMENT

• The experiment, too, was on the grandest scale.
  No fewer than three hundred thousand people of
  both sexes, of every age and occupation, and of
  every rank and station, from gentlefolks down to
  the very poor were divided in to two groups
  without their choice, and, in most cases, without
  their knowledge one group being supplied with
  water containing the sewage of London, and,
  amongst it, whatever might have come from the
  cholera patients, the other groups having water
  quite free from such impurity.

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AUSTIN BRADFORD HILLS CONTRIBUTION (1900)
AUSTIN BRADFORD HILL, in mid 1900, gifted to the
concept of Randomization for the epidemiological
growth. It enhanced the value of all the
experiments that were carried in later years as
it eliminates the biases (systematic errors) and
neutralizes all the known and unknown confounders
in the studies. In the present century, any
scientific experiment, test, drug, method is
accepted only after it is subjected to randomized
controlled trials. All present clinical trials
are randomized ones and as the randomization
made the procedure more scientific, it is carried
out first in any study. His experiments in 1954,
to prove causal relationship between smoking and
lung cancer really speeded up the growth of
epidemiology.
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FLETCHERS CONTRIBUTION (1905)
FLETCHER(1905) studied Beriberi that occurred
in lunatics in mental asylum in Kuala Lumpur
(Malaysia) and proved that it is due to
nutritional deficiency and not a place disease
as suggested by Sir Patrick Manson. In this
true experiment, he allocated the lunatics into
two groups, one to receive parboiled rice and
other to get Siamese rice (polished one).
Siamese rice group had higher number of deaths
when compared to cured parboiled rice group. He
later changed the wards and found the same
results thereby disproving that it is a place
disease.
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FLETCHER EXPERIMENT

• By June 20th many cases of beri-beri had occurred
  amongst the patients in the east ward who were
  eating uncured rice, whereas no cases had
  occurred in the west ward, the inmates of which
  were dieted on cured (Indian) rice.
• In view of the theory so strongly advocated by
  Sir Patrick Manson that beri-beri is a place
  disease, it was thought possible that the
  eastward was infected. Therefore on June 20th
  the patients were a, those on uncured rice being
  moved to the westward and those on cured (Indian)
  rice transferred to the east. From June 20th to
  Dec. 31st no beri -beri developed among the
  patients on cured rice although they were living
  in a ward where beri-beri had been rife amongst
  the lunatics who were fed on uncured (Siamese)
  rice.

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GOLDBERGERS CONTRIBUTION (1915)
GOLDBERGER JOSEPH (1915) proved that Pellagra
is not an infectious disease as it was thought
earlier, but a nutritional deficiency state. He
induced pellagra experimentally by providing a
diet deficient in Nicotinic acid and conducted
studies in several rural communities and in
institutions to demonstrate conclusively that
pellagra was a dietary deficiency disease.
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DEVELOPMENT

• SLIDES 25 TO 32

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INTERNATIONAL CONTRIBUTION
FOR DEVELOPMENT

• WORLD HEALTH ORGANIZATION
• UNICEF
• USAID
• PRIVATE FUNDING AGENCIES
• GLOBAL NETWORK OF NON-GOVERNMENTAL ORGANIZATIONS
• WORLD WIDE WEB (INTERNET
  EPIDEMIOLOGY)

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20 TH CENTURY DEVELOPMENT
PARBOILED RICE FOR TREATING BERIBERI IN LUNATICS
Fletcher
1905
INDUCED PELLAGRA BY DIETARY MODIFICATIONS
Gold Berger Wheeler
1915
OXYGEN THERAPY RETROLENTAL FIBROPLASIA
Kinsley Hemphill
1942
1946
WHOOPING COUGH VACCINE TRIAL
Medical Research Council (UK)
CORONARY HEART DISEASE
Framingham Heart Study
1948
Doll
SMOKING LUNG CANCER
1952
SMOKING LUNG CANCER
A.B. Hill
1954
LEUKEMIA DUE TO IRRADIATION TREATMENT FOR
ANKYLOSING SPONDYLITIS
Brown Hill
1955
ORAL CONTACEPTIVES HEALTH
Doll
1969
ADENOCARCINOMA OF VAGINA IN YOUNG WOMEN
Boston Hospital Study
1971
WHO CLOFIBRATE CLINICAL TRIAL, OSLO STUDY, NORTH
KARELIA PROJECT, MRFIT(USA), STANFORD THREE
COMMUNITY STUDY, BETA BLOCKERS IN MYOCARDIAL
INFARCTION, ASPIRIN STUDY,
20th cen- tury
TO REDUCE CARDIOVASCULAR MORTALITY
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FEW 21ST CENTURY DEVELOPMENTAL STUDIES
ANTENATAL FOLATE SUPPLEMENTATION TO REDUCE NEURAL TUBE DEFECTS
BETA CAROTENE IN DIET TO PREVENT CANCERS
ARSENIC STUDY IN HUMAN CANCERS
IN URANIUM WORKERS FOR LUNG CANCERS
POLYVINYL CHLORIDE ANGIOSARCOMA OF LIVER
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21ST CENTURY DEVELOPMENT
COLLOBORATIVE APPROACH IS ACCEPTED BY WORLD AS
MOST FEASIBLE WAY OF DOING THINGS
RANDOMIZED CONTROLLED TRIALS ACCEPTED BY WORLD
AS SCIENTIFIC NECESSITY
WORLD WIDE WEB (GLOBAL HEALTH NETWORK)
SUPERCOURSE AIMED AT UNIVERSAL DISTRIBUTION OF
EPIDEMIOLOGICAL INFORMATION
MULTICENTRIC TRIALS ARE FOLLOWED BY THE WORLD TO
PROVE THE CONSITENCY
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SCOPE FOR FURTHER DEVELOPMENT

• VERY VAST BECAUSE EPIDEMIOLOGY ENGAGES THE
  MOST HONEST SERVINGMEN OF VON KIPPLING VERY
  WISELY.
• ANY ASPECT OF LIVES OF THE POPUPATION CAN BE
  QUESTIONED WITH WHY, WHAT, WHEN, WHERE, WHOM
  AND HOW. THERE IS NO RESTRICTION FOR ITS
  TRANSGRESSION FROM PAEDIATRICS TO GERIATRICS.
• INTERNATIONAL ACCEPTANCE AND DEPENDENCE ON
  EPIDEMIOLOGY TO MANAGE AND SOLVE HEALTH PROBLEMS
  MAKES ITS DEVELOPMENT MANDATORY NOW AND IN
  NEAR FUTURE.
• WORLD WIDE WEB (GLOBAL HEALTH NETWORK
  SUPERCOURSE) WITH ITS EXTENSIVE NETWORK
  ENRICHES THE QUALITY AND QUANTITY OF
  EPIDEMIOLOGICAL INFORMATION TO THE PUBLIC WHO
  WILL IN TURN APPRECIATE, ACCEPT, GET BENIFITTED
  AND NATURALLY PROMOTE ITS GROWTH DEVELOPMENT.

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SUMMARY CONCLUSIONS

• NO ONE CAN CONCLUDE OR SUMMARISE AS
  EPIDEMIOLOGICAL GROWTH DEVELOPMENT AS IT IS A
  PHILOSOPHICAL STUDY OF A HEALTH PROBLEM. HENCE WE
  CANNOT PUT A FULLSTOP ANYWHERE FOR
  EPIDEMIOLOGICAL GROWTH. IT WILL BE GROWING IN ALL
  DIRECTIONS AS LONG AS APPLIED COMMONSENSE IS
  PREVAILINGLE WITH EPIDEMIOLOGISTS AND PUBLIC.
• GREAT BEGINNING HIPPOCRATES ADVISED, GRAUNT
  AND FARR COUNTED AND ANLYSED THE CASES, SNOW
  EXPLOITED EXPERIMENTED THE NATURAL EVENT TO
  TKNOW HOW ITS SPREADS. LIND, FLETCHER
  AND OTHERS EXPERIMENTED AND HENCE THEY BECAME THE
  FORERUNNERS OF EPIDEMIOLOGY AND PAVED THE WAY FOR
  OTHERS AND TAUGHT OTHERS WHAT IS EPIDEMIOLOGY AND
  HOW IT SHOULD BE PRACTICED.

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REFERENCES

• Brian Mac Mahan -Epidemiology-principles
  methods
• Roger Detels, James Mc Even-Oxford Text Book of
  Public Health
• Maxcy-Rosenau-Last, Public Health Preventive
  medicine
• Brett Cassens - Public Health Medicine,
  National Student Series.