Kotulán: Introduction
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Introduction                      to Preventive Medicine
  Jaroslav Kotulán

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TWO BASIC ASPECTS OF MEDICINE
l1. Biological and technological aspect
ØBiology: studying the structure and function of tissues and organs in health  and disease
ØTechnology - of examination of body structure and                functions - diagnosis
l    - of repairing defects and solving troubles - therapy
Object of the study (care) - an individual
Basic question: What are the health problems of Mr. ......
Methods: clinical

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2. Social aspect
Ø    studying health as a mass phenomenon
Object of the study (care) - group of people (population) e.g. population of the ČR, inhabitants of
Brno, schoolchildren in Prague etc.
Basic question: What are the health problems of the population of ....
Methods of diagnostics: epidemiology, statistics etc.
Methods of therapy: health programs
Medical disciplines dealing with the second aspect: public health, preventive medicine, social
medicine, community health, epidemiology etc.

Distribuce
Determinanty
Populace – geograficky, dle povolání aj., obvykle i podle pohlaví a věku

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EPIDEMIOLOGY
–The term is derived from three Greek roots (epi meaning upon, demos meaning people, and logia
meaning study). It was originally applied to the study of outbreaks of acute infection diseases and
was defined as the science of epidemics.
Definition: Epidemiology refers to the study of the distribution and determinants of diseases or
conditions in a defined population.
Epidemiology is based on two fundamental assumptions:
      Diseases do not occur by chance
Ø    Diseases are not distributed randomly in the population
ØThus, their distribution indicates something about how and why that disease process occurred.

Something from above coming to threaten (thre..) people

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Historical notes
Hippocrates (c. 460-370 BC): environmental factors can influence the occurrence of disease
 It was not until the 19th century that the distribution of disease in
                        human population groups has been measured
> onset of modern epidemiology
Not much progress during the middle age
Some correct measures: isolation of the sick, burning of           contaminated objects
No knowledge about causes of the spreading

Hippokrates (460 – 377) před n.l. : „O vzduchu, vodách a místech“ – vztahu nemocí a životního
prostředí
         odpozorováno

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John Snow (1813-1858), a physician in London,
in the time of severe epidemics of cholera (1848, 1853 etc.)
Commonly accepted theory about the cause at that time:
„miasma“ – something in the air („all smell is disease“)

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On a map of London, he located the home of each person who died from cholera in 1848-49 and 1853-54
epidemics
He found an apparent association between the source of drinking-water and the deaths (see the
table)
John Snow doubted about that miasma theory
He noticed that the distribution of the disease in the town was not regular:
different density of cases in different streets or localities
He saw no associatons with polluted air, elevation above sea level, weather and season, social
status etc.

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CHOLERA MORTALITY IN LONDON IN THE 4 WEEKS ENDING AUGUST 5, 1854
Water Company
Houses Supplied
Deaths in 4 weeks
Rate per 10 000 houses
Southwark and
Vauxhall
  40 046
286
71
Lamberth
26 107
14
5
All others
287 345
277
9
He proposed the hypothesis about the communication of infectious diseases in general and
     > suggested that cholera was spread by contaminated water
30 years before Koch isolated and identified  the cholera vibrio

From Snow J: On the Mode of Transmission of Cholera, 2^nd ed., London, Churchill, 1855
John Snows „Natural Experiment“, Cholera in London, 1854. Snow visited houses where people had died
of cholera and found out which company had supplied their drinking water. Competing companies often
supplied different houses in the same street. The Southwark and Vauxhall Company drew its water
from the river Thames downstream, where it was polluted; the Lamberth Company drew water upstream
from London, where it was free of pollution

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Ignaz Semmelweis (1818-1865), Hungarian physician,
head of Obstetrical Clinic in Vienna (since 1847)

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Puerperal sepsis („puerperal fever“, „childbed fever“) was common in mid-19th-century hospitals
-mortality at 10% to 35%,
-much more than with deliveries at home (or preterm in the street)
-causes not known, believed to be non-preventable
Semmelweis studied the occurrence of cases according to place and time:
two obstetric clinics : mortality in I. Clinic 13,1%, II. Clinic 2,03%
in the same hospital, the same techniques used
Only difference: education of students in the I., of midwives in the II.
Much less cases in summer, in the time of vacations

Do you know the history of his discovery?

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Semmelweis noticed in autopsies that pathological findings in puerperal sepsis were very similar to
the findings in the sepsis after the injury in the dissecting room  (1848)
He immediately proposed a connection
cadaveric contamination → puerperal fewer
the students carried some „cadaveric material“ on their hands
The discovery of pyogene streptococcus considerably later: Pasteur 1879, Rosenbach 1884
Semmelweis instituted a policy of using a solution of chlorinated lime for washing hands and later
also instruments and bandage
Incidence of puerperal fever: 12,24% → 1,25%
NB: only exact observation, records and their analysis

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Goals of epidemiology
Ø       Identify factors that cause disease or disease transmission
Ø      Prevent the spread of communicable and
              non-communicable diseases and conditions

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Types of epidemiologic studies
1.Descriptive
2. Analytic

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Descriptive studies
l   describe the distribution of cases by the variables of person, place, and time in order to
study and describe acute outbreaks of disease, to follow secular trends of disease occurrence over
time, and to develop hypotheses about disease transmission.

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Mortokrmap

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Strokerate

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Analytic studies
l   such as the retrospective (case-control) studies and the prospective (cohort) studies, identify
causal relationships or factors associated with disease. In most cases, analytic studies do not
prove cause and effect, but there are used to generate hypotheses that can be tested.
a) Observational
b) Experimental

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Experimental studies
Øe.g. vaccine field trials and clinical studies that evaluate therapy
Placebo controlled double blind test
are carefully designed to prove an association between a factor and disease outcome
Ø  giving vitamins, antioxidants etc. and studying the preventive effect

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Tools for measuring health status of a population
ØMortality
§standardized mortality ratio (SMR), mortality in the productive age, years of potential life lost
(YPLL)
§life expectancy (at birth)
ØMorbidity      - prevalence
             - incidence

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Life expectance at birth           in Europe
ØGreat differences amongst countries
l levels
l trends
ØČR needs to improve its position amongst European countries
- stress on prevention

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Causes of the health differences amongst European countries
l Nutrition?
l Smoking?
l Obesity? Hypokinesis?
l Stress?
l Polluted environment?
l     Health care quality?

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LifespantrendCR

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ØNecessity of better prevention is felt also in affluent countries
l reason: rapidly growing expenses on health care
l eg. USA: Program Healthy People 2000

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USAcosts

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Determinants of National Health:
Ølife style (nutrition, autoagression, stress, work and rest, health habits)
Ø environment (regional, local, professional, individual)
Øhealth care

Neštovice: Program WHO zahájen v r. 1967, tehdy 10 – 15 mil. Nových případů ročně, 2 miliony
zemřelých/rok
Jódová prevence od r. 1915

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Health Programmes
Ø„Postinfectious era“
ØFirst Health Programs: North Karelia etc.
ØTypes of programmes
- disease approach
- factor approach
- settings approach („Healthy City“,  „Healthy School“ etc.)

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Complex Programs
Ø Health for All 2000,   HFA 21
Ø Healthy People 2000
          Healthy People 2020
Ø  National Programs

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PREVENTIVE MEDICINE
l   Preventive Medicine is the branch of medicine that concentrates on keeping people well.

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Goals of Preventive medicine
a. Disease prevention deals with techniques that prevent the occurrence of disease (physical,
mental, or emotional) or lead to an early diagnosis where therapy may cure, prevent, or modify the
progression of disease.
b. Health promotion deals with techniques that foster physical and emotional well-being and
increase the length and quality of life. It deals with the fact that many diseases are not caused
by unknown or unpredictable factors, but by personal, modifiable lifestyle habits. Modifying a few
lifestyle habits, such as poor diet, infrequent exercise, unprotected sexual intercourse, lack of
prenatal care, failure to use seat belts, and the use of tobacco, alcohol, and drugs, could reduce
one-third of all cases of acute disability, two-thirds of all cases of chronic disability, and 40%
- 70% of premature death.

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Levels of prevention
a) primary, b) secondary, c) tertiary
l a. Primary prevention is the prevention of disease or injury. Primary prevention activities can
be directed at individuals or at the environment.
(1) Health education: encouraging people to develop good health habits (nutrition, exercise), to
avoid  harmful substances (alcohol, tobacco, drug abuse) and harmful circumstances (driving while
intoxicated) and to use specific protective measures (e.g., immunizations, condom use).
         (2) Environmental modification can decrease injuries from falls, fires, or automobile
accidents. Environmental sanitation is used to provide an adequate sewage system, safe drinking
water, clean air, and environment free of toxic substances.

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b. Secondary prevention
l is the early detection and prompt treatment of disease.
(1) Screening programs are used to detect diseases in early preclinical stages, when effective
therapy may either cure the disease or limit its progression (e.g., neonatal detection of
phenylketonuria, the Pap test to detect in situ carcinoma of the cervix, glaucoma testing).
          (2) Primary medical care is the predominant form of secondary prevention. Most health
expenses are spent on, and most health care personnel are employed in, primary care.
    c. Tertiary prevention is the limitation of disability and the rehabilitation from disease. It
emphasizes a person’s remaining abilities and attempts to restore the person to as normal a life as
possible.

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Epidemiology and prevention of infectious diseases
Ø  Elimination of disease-causing agent: desinfection, sterilization, chlorination, pasteurization
etc.
Ø  Control of the reservoir: isolation, quarantine, chemotherapy, animals (wild animals, pets),
mosquitoes etc.
Ø  Control of the transmission: direct transmission (hand washing, individual towels, condom use
etc.), indirect transmission (air, water, food, arthropod vectors - mosquitoes, mites, ticks),
Ø  Protection of the susceptible host: (immunization, chemoprophylaxis, good health habits etc.)

Roztoč, klíště, bodnout – sting, stang, stung, ničit bakterie – to control germs

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Epidemiology and prevention of chronic illnesses
l Heart disease, Cerebrovascular disease
   Cancer
  Chronic obstructive pulmonary disease
Cirrhosis
 Diabetes
 Renal Disease
Anaemia
Peptic ulcer
Osteoporosis etc.
Most important:

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Mortpříč
II. Neoplasms
IX. Circulatory system
X. Respiratory system
XI. Digestive system
XIV. Genitourinary system
XX. External causes   (injury, poisonings)

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DiabetestrendCR
PAD … Peroral antidiabetics (derivatives of sulphonilurea, biguanides etc.)

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Branches of preventive medicine
l Environmental health
Basic problems:
¨      Air pollution (ambient air, indoor air)
¨      Water pollution, water supply, drinking water
¨      Food contaminants
¨      Noise
¨      Radiation
¨      Wastage, sewage
In continental Europe: Hygiene

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 NEW ISSUES – SOME INSTANCES
Endocrine disruptors
= exogenous substances that interfere with the endocrine system and disrupt the physiologic
function of hormones
Some of them block the cell receptors, others stimulate or inhibit the endocrine system
They have adverse biological effects in animals                  - adverse developmental and
reproductive effects on fish and wildlife
Ø    Modulation of reproductive endocrinology, adrenal, thyroid, and growth hormone function
Rising concerns that low-level exposure might cause similar effects in human beings
Xenoestrogens mimic the hormone action of estrogens (xenos = foreign)

:endekrin dis:rapt int r:fie

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Diethylstilbestrol (DES),
a drug that for years had been prescribed to women to prevent miscarriage
In the 1970s, its hormonal toxicity was discovered
- later causing cancer and infertility in some of the children of these mothers
Other endocrine disruptors
phtalates – chemicals used in plastics > mouthing toys for children, plastic tubing in medical
devices
bisphenol A (BPA) used in manufacture of plastics and epoxy resins (rezin)
food can liners, food storage containers, baby bottles, water supply pipes, dental resins.
The alone United States produces 700 000 kg BPA annually, nowadays is found in stream water, in
adult´ s blood, in amniotic fluid, and placental and fetal  tissues –lifelong exposure may be hard
to avoid
Dioxins (polychlorinated dibenzodioxins), PCBs (polychlorinated biphenyls), PAHs (polycyclic
aromatic hydrocarbons)
furans, phenols,
several pesticides (also DDT dichloro- diphanyl trichloroethane)
17- beta ethynilestradiol (the contraceptive pill)
genistein –phytoestrogen found in soy
etc. - a long list.

plastics (plastik) manufacture (menju:fäkčr (fyto:esttr dž n)
gene – džín genome – dži:noum

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Nanotoxicology
Nanotechnology
= using engineered materials with diameters  of  < 100 nm (size of molecules and atoms)
For comparison, typical carbon-carbon bond length, or a spacing between these atoms in a molecule,
are in the range 12 – 15 nm and DNA double-helix has a diameter around 2 nm.              The
smallest bacteria of the genus Mycoplasma are around 200 nm in length.
2g of 100 nm diameter nanoparticles contains enough material to provide  every human worldwide with
300 000 particles each.
Materials reduced to the nanoscale can suddenly show very different properties compared to what
they exhibit on a macroscale, enabling unique applications.
For instance:
Ø opaque substances become transparent (copper)
Ø inert materials become catalysts (platinum)
Ø stable materials turn combustible (aluminium)
Ø solids turn into liquids at room temperature (gold)
Ø insulators become conductors (silicon)
Widespread applications in medicine, plastics, energy, electronics (molecule sized transistors,
chips, PCs),  aerospace etc.
„The biggest engineering innovation since the Industrial Revolution“

opaque ou:pejk Platinum :pla  combustible ) k n:ba
silicon :silik n

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In medicine: in vivo biomedical imaging, disease diagnoses, drug targeting, cancer treatment
“Quantum dots” (QD) – semiconductor nanocrystals (2 – 100 nm) with unique optical and electrical
properties.
Their fluorence spectrum renders them optimal fluorophores for biological imaging. Fluorescent QDs
can be conjugated with bioactive moieties (e.g. antibodies, receptor ligands) to target specific
biologic events and cellular structures, such as labeling neoplastic cells. They are being explored
as tools for site-specific gene and drug delivery.
Combination of their crystalline metalloid core structure and
 a “cap” or “shell” that shields the core and renders the QD biovailable

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QuantumDot

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The worldwide market for production using nanotechnology is estimated to reach US$ 1 trillion by
2012.
Nanoproducts are sold by more than 200 companies globally (electronic, cosmetic, suntan lotions,
protective coatings, stain resistant clothing).
These materials in society will be increasing,  as will the likelihood of exposures.
Exposure  through inhalation, ingestion, skin uptake and injection.
Potential adverse human effects
 New discipline – nanotoxicology. Studies of absorption, distribution, metabolism, excretion and
toxicity of nanoparticles.

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Occupational health (1)
lPossible impacts:
ldeath
ldisease
limpairment (the objective description of the loss of function of the human body)
ldisability (the effect of an impairment on the ability of an individual to function in the
society)

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Occupational health (2)
lPotential hazards
l¨      Metals (arsenic, cadmium, chromium, lead, mercury etc.)
l¨      Solvents (aliphatic and aromatic hydrocarbons, alcohols, glycols, esters, halogenated
hydrocarbons  etc.)
l¨      Dusts (asbestos, coal, silica, organic dusts etc.)
l¨      Pesticides: Insecticides (organophosphorous compounds, organochlorine compounds - e.g. DDT,
etc), fungicides (organic mercury compounds), herbicides etc.
l¨      Asphixiant gases (carbon monoxide, hydrogen cyanide etc.)
l¨      Physical stressors (noise, vibration, heat, cold, injury)
l¨      Radiation (ionizing, ultraviolet)
l¨      Biologic hazards (brucellosis, tularaemia, leptospirosis, hepatitis, fungal diseases etc.)

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lCommunity health
 Epidemiolody and prevention of injuries
Mental health
etc.

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l
l
l
SO01862_
Thank you                                      for your       attention

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