Transcript Section A: Introduction - University of Arkansas

Section A: Introduction
Dr. Jones
University of Arkansas
Human Disease
History of Disease
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4 Theories of Disease Causation
Evil spirits and supernatural beings
 Contagion
 Germ
 Multiple causation (agent-environment-host)
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Years in Age
Life Expectancy
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80
70
60
50
40
30
20
10
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Years
Wow! Bad graph, huh?
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Why?
LE Data pre-1750 are not solid.
 Much from special populations
(wealthy landowners, popes, etc) –
not representative.
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Jonker, 2003; Wilmoth, 2000
Evil Spirits and Gods
4000 to1000 BC
 Egyptians used medicine and magic
 Treatment used drugs such as
Castor oil
 Olive oil
 Opium
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Some treatment methods still used today
Evil Spirits and Gods
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Chinese Medicine
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Herbal remedies
Opium as a narcotic
Iron to treat anemia
Invented acupuncture
Contagion Theory
460BC to 1790AD
 World Events Effecting Disease
Religion
 Travel (spread of disease)
 Lack of scientific study
 War (The Crusades)
 Plagues
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 Control
methods included isolation/quarantine
The Islamic World in Medicine
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8th century AD (CE) – 1st Bimaristan,
specialty hospital
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female nurses, first to employ female physicians
(separate wards made necessary)
865 to 930 - Al-Razi
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Three treatises; most influential, on smallpox and
measles, was translated into Latin in 1700s
Wakeel, n.d.
The Islamic World in Medicine
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Retaining/translating texts when knowledge
was being lost
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~1012 AD (CE) – Ibn Sina, Book of Healing
and Canon of Medicine
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Espoused mind-body connection, mental health, selfesteem; emphasized understanding causes of disease
13th century - Ibn an-Nafis, physician
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Challenged Galen’s view of the heart,
discovered pulmonary circulation
Mondalou, 2008; Stephenson, 2000; Wakeel, n.d.
Contagion Theory
Natural and humanistic causes
 Hippocrates (Father of Medicine-430 BC)
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Developed belief of 4 humors (fluids)
 Blood,
Phlegm, Yellow & Black Bile
Disease caused by imbalance
 Bloodletting was preferred treatment
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Galileo (1609 AD) discovered first
microscope
Contagion Theory
Major Diseases
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Plague
Typhoid
Typhus
Diphtheria
Streptococcal
Small pox
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Dysenteries
Syphilis
Cholera
Anthrax
Leprosy-Hansen’s
Disease
Contagion Theory
Major Discoveries
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Galen (168 AD (CE))-Imperial physician for
Roman empire provided the best knowledge of
the human anatomy.
Leonardo da Vinci/Andreas Vesalius (1540 AD)
showed that Galen’s work was incorrect and
based on animals.
Antonie Van Leeuwenhoek (1683) was the first
to use a microscope to identify bacteria.
Germ Theory (1800 to 1940)
Specific Cause – Specific Disease
 Girolamo Fracastoro (1550)
 Edward Jenner (smallpox vaccination)-1796
 Louis Pasteur (pasteurization)
 Robert Koch (4 postulates of disease
causation)
Koch’s 4 Postulates
1.
2.
3.
4.
Always be present
in the disease
Capable of growth
in the lab
Cause disease
when injected in an
animal
Can be recovered
from the animal
Germ Theory (1800 to 1940)
Claude Bernard (digestion/endocrine
system)
 Joseph Lister (developed antiseptic)
 Marie & Pierre Curie (discovered Radium)
 Roentgen (X-rays)
 Electron Microscope (1930)
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Multiple Causation (1850 - Present)
One Disease – Multiple Causes
 Cancer & Heart Disease
 Emergence of non-infectious disease
 Medical technology and new medicines
 Epidemiology
 Public health movement
Multiple Causation (1850 - Present)
Major Discoveries
 Vitamins and deficiency diseases (Beriberi
Pellagra, Rickets, Scurvy)
 Paul Ehrlich (specific chemical agent –
Syphilis)
 Alexander Fleming (Penicillin)
 Jonas Salk/Albert Sabin (vaccine for
Poliomyelitis)
Multiple Causation (1850 - Present)
Major Disease Investigation
 Framingham heart Study (identified risk
factors of heart disease)
 Nurses Health Study
 Tuskegee Study (Human Subject Review
Boards)
 ACS Cancer Prevention Study (largest
cohort study)
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1 million people from 1959 – 1972 in 25 states
Non-Infectious
Disease Deaths
400
300
200
Infectious
Disease Deaths
100
1920
1930
1940
1950
1960
1970
1980
Pneumonia
Tuberculosis
Diarhhea
Heart Disease
Stroke
Liver Disease
Injuries
Cancer
Senility
Diptheria
Heart Disease
Cancer
Stroke
Chronic Lung Disease
Unintentional Injuries
Pneumonia and Flu
Diabetes
Suicide
HIV Infection
Suicide
Liver Disease
History of Public Health
Roman Civilization (100 BC-300 AD)
 Developed concept of public health
Built aqueducts
 Built sewers
 Street cleaning
 Physicians tended to the poor
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History of Public Health
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Modern (1850 to Present)
British Public Health Act of 1848 (Edwin
Chaddick)
John Snow investigates Cholera
1850 – American Lemuel Shattuck publishes
recommendations for public health
American Public Health Association
Focus on school health
Distribution of cholera cases, Golden Square area of London, Aug/Sept 1854
Recommendations for Public
Health
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Lemuel Shattuck
Establishment of state & local health dept.
Hiring sanitary inspectors
Keeping vital statistics
Establishment of school health
Studies of tuberculosis
Supervision of the mentally ill
Study of immigrants’ problems
Building of model tenements
Recommendations for Public
Health
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Establishment of public restrooms
Control of smoke nuisances
Control of food adulteration
Exposure of quack medicines
Preaching of health in the churches
Training schools for nurses
Teaching of sanitary science in medical school
Include preventive medicine in clinical practice
Public Health
What is it?
 Activities that a society undertakes to
assure the conditions which people live
are healthy and safe. Included are
community efforts to prevent, identify, and
counter threats to the health of the public.
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Examples:
Public Health vs. Medical Care
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Medical Care
Treatment
Individual
Health care
Unlimited $
Individual supported
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Public Health
Prevention
Community
Multidiscipline
Limited $
Taxpayer supported
Section B: Epidemiology
Dr. Jones
University of Arkansas
Human Disease
Epidemiology

The study of the distribution and
determinants of disease frequency in
human populations
Distribution
 Determinants
 Populations
 Frequency
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Key Terms
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Epidemic – excessive occurrence of disease
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Pandemic – epidemic over a large area,
such as a country, continent, or the world
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Endemic – constant presence of a disease,
specific to a region or population; usual or
expected frequency of a disease
Main Concepts of Epidemiology
1.
An analytic, descriptive component
termed classical epidemiology, and
2.
A diagnosis, management of illness, and
critical review of literature termed clinical
epidemiology.
3 Levels of Prevention
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Primary – prevention of the development
of disease
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Secondary – early detection and
treatment of disease
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Tertiary – rehabilitation and/or restoration
of effective functioning after the treatment
of disease
Epidemiologic Surveillance
Definition
The ongoing process and systematic
collection, analysis, and interpretation of
health data in the process of describing
and investigating the health status of a
population.
Current Uses of Epidemiology
Identifying the etiology and cause of a new
epidemic or syndrome
 Example:
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Carpal Tunnel Syndrome
 Ebola Virus Epidemic
 Post Traumatic Stress Syndrome
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Current Uses of Epidemiology
Investigating the risk associated with a
harmful exposure
 Example:
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Radon exposure
 Lead
 Environmental tobacco smoke (ETS)
 Dioxin
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Current Uses of Epidemiology
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Determine if a treatment is effective
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Example:
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Comparison of survival rates after segmental and total
mastectomies
Study/identify health service utilization needs and
trends
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Examples:
Effect of health insurance coverage on health services used by
poor and near poor populations
 Impact of youth violence on ER services and utilization
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Current Uses of Epidemiology
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To provide
rationalization and
justification for health
policy planning
Example:
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Smoking bans
Gun-control laws
Drunk-driving laws
Hazardous waste
regulations
Epidemiological Models
Chain of Infection
 Traditional Model
 Health Field Concept
 Acute vs. Chronic Disease
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Chain of Infection
Chain of Transmission
Direct or Indirect
Host Susceptibility
Portal of Entry
Vector
(animate, inanimate)
Pathogenic Agent
Reservoir
(human, animal, or inanimate)
Portal of Exit
Transmission
Direct
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Direct Contact
Kissing
 Skin-to-skin
 Sexual intercourse
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Droplet Spread
Sneezing
 Coughing
 Talking
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Transmission
Indirect
 Airborne (dust, droplet nuclei)
 Vehicleborne (food, water, etc.)
 Vectorborne (ticks, mosquitoes, etc.)
Traditional Model
Environment
Agent
Host
Health Field Concept
Biology
Heredity
Environment
Lifestyle
Health
Care
System
Health Field Concept
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Lifestyle
Leisure
 Consumption patterns
 Employment/occupational risks
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Environment
Physical
 Social and psychological
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Health Field Concept
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Human biology
Genetic Inheritance
 Maturation and aging
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Medical Care System
Preventative
 Restorative
 Curative
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Infectious Disease
Cause – Diagnosis – Treatment – Severity
 Disease of short duration
 Affects mainly the young
Chronic Disease
Cause – Diagnosis – Treatment (cure)
 Disease of long induction period
 Time allows multiple causes to develop
 Affects mainly the old
Concept of Risk
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With multiple causes and chronic
diseases, epidemiologists like to refer to
the concept of causality based on the odds
(risks, chances) of the occurrence of
disease or health status as associated
with the occurrence of another (risk factor)
Limitations of Epidemiology
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It is difficult to assess risk from
epidemiological data because:
1.
Research studies on humans are sometimes
unethical, expensive, and difficult to obtain
2.
Chronic disease situations often find very low
risks
Limitations of Epidemiology
3.
The number of persons with the disease or
exposure is very small
4.
Latency period between exposure and disease
status are sometimes many years apart
5. Humans may be exposed to multiple chemical,
biological , and physical hazards
Types of Epi Strategies Used
1.
2.
3.
Descriptive
Analytic (retrospective – case-control,
prospective – longitudinal/cohort, &
cross-sectional)
Experimental (cause & effect)
Descriptive & Analytic
Epidemiology
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Descriptive Epidemiology – amount and
distribution of disease within a population
by person, place, and time
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Analytic Epidemiology – more focused
study on the determinants of the disease
or reason for relatively high or low
frequency in specific groups
Ask These Questions
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Who (person) – D
What (type of disease, illness, disability) – D
When (time) – D
Where (place) – D
How (etiology or cause of event) – A
A = analytic
D = descriptive
Descriptive
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Person
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3 main characteristics:
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Age
Gender
Ethnic group/race
Age
It is the most important determinant
among the person variables
 Mortality and morbidity rates of most
conditions show some relation to age
 Infectious diseases – younger
 Chronic diseases – older
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Gender
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Mortality is higher
among males
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Morbidity is higher
among females
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Why?
Gender
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Mortality – linked with inheritance,
hormonal balance, environment, or habit
pattern
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Morbidity – women have higher rates of
illness and more physician contacts than
men. Possible reasons:
1.
2.
Women seek medical care more freely &
perhaps at an earlier stage of disease.
The same disease will tend to have a less lethal
dose in women than men.
Ethnic Group
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Classifying people by ethnic group is
difficult but important in the field of
epidemiology. Why?
1.
2.
Many diseases differ in frequency, severity, or
both in different racial groups and
Statistically by race are helpful for identifying
health problems
Other Person Variables
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Social class
Occupation
Marital Status
Family Variables
Family Size
Birth Order
Personality traits
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Maternal Age
Parental Deprivation
Blood Type
Environmental
Exposure
Place Considerations
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Frequency of disease can be related to
place of occurrence by:
Natural boundaries (these are more useful &
include things like rivers, deserts, mountains)
 Political subdivisions (these are more
convenient)
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Place Considerations
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Mapping environmental factors
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Urban-Rural differences
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International comparisons
Time Considerations
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3 major time measurements:
1.
Secular trends (long-term variations)
2.
Cyclic (recurrent alterations in the frequency of
disease)
3.
Short-term fluctuations
Study Design Definitions
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Confounding – illusory association between two
variables. The association is caused by a 3rd
factor, “confounder.” major confounders are age,
gender, and smoking
Bias – subjects chosen for the study are
unrepresentative of the population. Types of
bias include: (over 57 types)
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Healthy worker bias
Information
Volunteer
Study Design Definitions
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Chance – making assumptions and
inferences of the measure of disease
frequency concerning the experience of a
population based on an evaluation of only
a sample. Because of chance variation, for
any two samples in a population to be
identical is highly unlikely.
Chance-example via checkerboard
Types of Study Designs
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Case Report or Case
Series
Descriptive
(Population-based)
*Follow-up
(Population-based)
*Case-Control
Follow-Up Studies
Retrospective
Prospective
Retrospective

People diagnosed as having a disease are
studied to determine past exposure to
various risk factors
Past
Present
Look for past
exposure to factor
in diseased people
Select
individuals with
the disease
Retrospective
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Strengths
Less expensive
 Faster to do study
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Limitations
Impossible to control for confounding factors
 Bias prone
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Prospective
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Study starts with a group (cohort ) of people who
are free of disease, but who vary according to
exposure to probable disease factor
Present
Future
Select cohort &
classify as to
exposure to factor
Follow-up to see
frequency with
which disease
develops
Prospective
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Strengths
Temporal sequence is clear
 Bias and confounding are relatively easy to
control
 Absolute measures of occurrence are
available (incidence, mortality, etc.)
 Provides information on many factors
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Prospective
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Limitations
Very expensive and time consuming
 May not provide significant findings until after
5-10 years
 Inappropriate for rare diseases
 Problems with following up on new subjects
 Extremely inefficient
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Case Control Study
People are diagnosed as having a disease
(cases) are compared with persons who do not
have the disease (controls) with relation to various
risk factors
Past
Present
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Look for past
exposure to factor
in cases & controls
Select people with
the disease (cases)
Select people with
out the disease
(controls)
Case Control Study
Dominant form of epidemiologic study (> 80%)
 Difficult but rewarding design to use
 Case-control studies have been used in other
areas besides causation-preventive services
and health services research
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Case Control Study
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Strengths
Appropriate for rare diseases
 Appropriate for diseases with long induction
time
 Economical & done rapidly
 Allow evaluation of multiple hypotheses
 Extremely efficient
 Large amount of information on small amount
of subjects
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Case Control Study
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Limitations
People don’t understand it (abused)
 Study is poor when exposure of interest is
rare
 Only relative measures are available
 Bias prone
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Epidemiological Measurements
General Formula
Number of events
(cases, deaths, services)
in a specified time period
Population at risk of
Experiencing the event
X
10n
Using Rates & Risks
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Ecological fallacy
(generalizing)
Variations in base
(what base is used)
Variance in rates
(differences based on
rates)
Measures of Mortality
Crude Mortality Rate
 Infant Mortality Rate
 Case Fatality Rate
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Measures of Morbidity
Incidence Rate
 Prevalence Rate
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Crude Mortality Rate
General Formula
All deaths during
a calendar year
Total population
X 1,000 = deaths per 1,000
Crude Mortality Rate
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This rate expresses the actual observed
mortality rate in a population under study
and is considered the starting point for the
adjustment of rates
Infant Mortality Rate
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Most widely accepted measure for
estimating the health status of a
population
# of infant deaths*
(less than 1 year of age)
Total live births
*excludes fetal deaths
X
1,000
Case Fatality Rate
General Formula
# of deaths due to the
disease in a specific time period
# of cases of the disease in the
same time period
Expressed as a percentage (%)
X 100
Case Fatality Rate

This measure represents the probability of death
among diagnosed cases, or the killing power of
a disease
Example:
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In Sudan Africa, 34 people were infected with the Ebola
virus in 1979. Of those infected, 31 eventually died from
the disease
31
X 100 = 91%
34
Incidence & Prevalence

The two main measures of disease
frequency (morbidity)
Incidence – new cases of a certain disease
 Prevalence – ALL cases of a certain disease
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Incidence & Prevalence
Incidence
(new cases)
Death
Recovery
Prevalence Pot
Incidence

Incidence rates are designed to measure the
rate at which people without a disease develop
the disease during a specific period of time.
Incidence rate =
# of new cases of a
disease over a period of time
population at risk of the
disease in the time period
Incidence Example
Gonorrhea in Arkansas
1987
I = 8898 new cases of Gonorrhea
2,342,699 population
=381/100,000
1996
I = 5027 new cases of Gonorrhea
2,509,793 population
=200/100,000
Prevalence

Prevalence rates measure the number of people
in a population who have the disease at a given
point in time
Prevalence rate = total # of cases of a
disease at a given time
total population at a
given time
AIDS in Arkansas - 1996
County
Benton
Carroll
Pulaski
Wash
Pop’n
105,588
19,505 353,394 120,146
AIDS
4
1
24
2
46
18
499
124
6/949/94
AIDS
Total
Section C: Infectious
Disease
Dr. Jones
University of Arkansas
Human Disease
The Immune System
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Natural Nonspecific
Immunity
Acquired Immunity
Immune Disorders
Natural Nonspecific Immunity
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3 types
External Barriers
 Inflammation
 Natural Specific Immunity
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Natural Nonspecific Immunity
External Barriers
 Body’s first line of defense
 Defense Mechanisms
Skin protection
 Mucus secretion
 Body fluid secretion
 External protection by bacteria
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Natural Nonspecific Immunity
Inflammation
 A non-specific response to any foreign
agent that causes cell injury. Body’s first
line of defense upon penetration of a
foreign organism.
Acute Inflammation Response
Pathogen
Physical Agent
Chemical Agent
Tissue Injury
Mediators of inflammation
Capillary
Increased
Dilation
capillary
permeability
Increased
Extravasation
Blood Flow
of fluid
Heat Redness
Attraction of
Systemic
leukocytes
response
WBC go to
site of injury
Fever
Leukocytes
Tenderness
Swelling
Pain
Inflammation
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Healing Process
Two outcomes
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Recovery
Chronic inflammation
Inflammation
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Healing Process
Regeneration – replacing of lost tissue by the
same type of tissue (primary healing)
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Cells incapable of regeneration:
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Nerve
Heart muscle
Skeletal
Repair – replacing of lost tissue by connective
scar tissue (secondary healing)
Inflammation
Factors Effecting the Process
Age?
 Diet/Nutrition
 Blood Supply
 Previous Infection
 Foreign Organisms
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Natural Nonspecific Immunity
Natural Specific Immmunity
 2 types
Humoral immunity
 Cell-mediated immunity
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Humoral Immunity
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Production of antibodies
(immunoglobulins) that combine with and
eliminate foreign material. Main defense
mechanism against bacteria
Cell-Mediated Immunity

Formation of lymphocytes that attack and
destroy foreign material. Main defense
against viruses, fungi, parasites, and some
bacteria
Types of Leukocytes
(White Blood Cells)
Neutrophils
50-70%
 Lymphocytes
20-40%
 Eosinophils
1-3%
 Basophils (release histamine) -1%
 Monocytes (Macrophage)
1-6%
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Natural Nonspecific Immunity
Immune Response
 Types of Lymphocytes
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Thymus-dependent (T cells)
 Development
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of cell-mediated immunity
Bone marrow (B cells)
 Development
of humoral defense reaction
T lymphocyte
Sensitized lymphocyte
Cell-Mediated
Immunity
Macrophage
Processed
Antigen
Interaction
Antigen
interaction
B lymphocyte
"Memory Cells"
Humoral
Immunity
Plasma cell
Immune Response
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3 types of T cells
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Helper T Cells – help make antibody forming cells
from B cells (AIDS attacks these cells)
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Killer T Cells – interact with antigens and kill foreign
material
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Regulatory (Suppressor) T Cells – suppress
formation of antibody forming cells from B cells
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Natural Killer T Cells – involved in innate immune
system
Acquired Immunity
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4 types
 Active Natural
Immunity
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Active Artificial
Immunity
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Passive Natural
Immunity
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Passive Artificial
Immunity
Acquired Immunity
Active Natural Immunity

The individual is exposed to pathogen and
the body produces antibodies to destroy it
Acquired Immunity
Active Artificial Immunity

Vaccination with form (dead, weakened, or
attenuated) of the disease causing
pathogen thus enabling the body to
produce antibodies
Acquired Immunity
Passive Natural Immunity

Results from the transfer of antibodies
from a mother to her child through the
placenta.
Acquired Immunity
Passive Artificial Immunity

Inoculation of antibodies to destroy foreign
pathogen. Usually given to individuals
effected by rabies or tetanus
Acquired Immunity
Antibodies-Immunoglobulins
 5 types
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IgM
IgG
IgA
IgD
IgE
* Picture of an IgM
Immunoglobulins
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IgM – large antibody that is very effective
in combining with large antigens such as
fungi.
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IgG – smaller antibody that is formed in
response to the majority of the infectious
agents.
Immunoglobulins

IgA – produced by antibody-forming cells in the
respiratory and gastrointestinal mucosa.
Protects against harmful ingested or inhaled
antigens.

IgD – surrounds surfaces of lymphocytes
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IgE – present in small amounts in blood but
higher concentrations can be found in
individuals with allergies.
Immune Disorders

An individual form antibodies to his/her
own cells or tissues
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2 types
Hypersensitivity
 Autoimmunity
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Hypersensitivity
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4 major types
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Allergic Rhinitis
Urticaria
Angioedema
Asthma
Allergic Rhinitis (Hay Fever)

Reaction to airborne allergen. May be
seasonal or year round condition.
Cause – pollen, mold spores, house dust, cat
dander, cigarette smoke
 Symptoms – histamine and other chemicals
released by the body
 Prevention – avoid allergens
 Treatment – antihistamines reduce
symptoms, desensitization

Urticaria (Hives) & Angioedema

Skin condition characterized by itchy,
raised white lumps surrounded by red,
inflamed area.
Cause – reaction to chemical substance or
toxin
 Symptoms – rash
 Prevention – avoid allergen
 Treatment – antihistamines and skin lotions

Urticaria (Hives) & Angioedema
Asthma

Immediate or subdued spasms of the
bronchial tubes, increase mucous
secretion, and swelling of the mucous
membrane, and preceded by respiratory
infection
Cause – genetics, exposure to allergens,
stress
 Prevention – avoid allergens, predisposing
factors
 Treatment – adrenocortical drugs

Anaphylaxis

Anaphylactic Shock
A life-threatening rapid and serious allergic
reaction due to increase in IgE antibody
resulting in a narrowed airway.
 Cause: foods (nuts), vaccinations, antibiotics
(penicillin), other medicines, latex, insect
stings/bites, exercise.
 Treatment requires:

 Adrenaline
(epinephrine) injection to stabilize.
Asthma Prevalence, United States
Asthma Mortality
Autoimmunity

Rheumatoid Arthritis

Lupus Erythematosus

Immune-mediated
Diabetes
Rheumatoid Arthritis

Inflammation of joints, muscles, tendons,
ligaments, and blood vessels
Cause – unknown, possibly genetic
 Prevention – none known
 Treatment – aspirin, anti-inflammatory drugs

Lupus Erythematosus


Inflammatory disorder effecting the connective
tissue
2 types





Cutaneous: affects skin
Systemic: affects body organ systems
Cause – stress, bacterial & viral infections, sun
exposure
Prevention – none known
Treatment – corticosteroids for systemic lupus, avoid
sun exposure
Lupus Erythematosus
Immune-mediated Diabetes

The body destroys the cells in the
pancreas that produce insulin, leading to a
total failure to produce insulin and the way
the body uses food
Cause – unknown, possibly genetic
 Prevention – none known
 Treatment – monitor insulin, food, & blood.
Exercise is beneficial

Stages of Disease
1.
2.
3.
4.
5.
Incubation – agent enters body (latent)
Prodrome – first symptoms appear
(communicable)
Clinical – peak for symptoms
(communicable)
Decline – signs of recovery (carrier)
Convalescent – return to full health
(carrier)
Disease Causing Organisms
Prions
 Bacteria

Rickettsiae
 Chlamydiae
 Mycoplasma

Viruses
 Fungi
 Protozoa
 Metazoa

Prions

An infective group of complex organic
compounds (proteins) suggested as the
causative agents of several infectious
diseases

Examples:
 Creutzfeldt-Jakob
 Kuru
Disease (Mad Cow Disease)
Bacteria


Small, single-celled microorganisms that are the
most common cause of disease.
Diseases:







Cholera
Diphtheria
Most STDs
Most Foodborne diseases
Tuberculosis
Septicemia-bacterial blood infection
Nosocomial disease-Hospital acquired
Bacteria

Common Foodborne Diseases:
E. Coli
 Listeriosis
 Campylobacter
 Salmonella
 Botulism

Bacteria

Common STDs:
Chlamydia
 Syphilis
 Gonnorhea
 Herpes (virus)
 HPV (Human Papillomavirus) Genital warts

Treatment for Bacterial Infections

Use of Antibiotics
Inhibition of cell-wall synthesis
 Inhibition of cell-membrane function
 Inhibition of metabolic functions
 Competitive inhibition

Adverse Effects of Antibiotics
Toxicity
 Hypersensitivity
 Alteration of “friendly” bacteria
 Development of antibiotic-resistant
bacteria:

MRSA (and CA-MRSA)
 VRE
 MDTB

Rickettsiae
Microorganisms that resemble viruses and
bacteria
 Diseases include:

Typhus (body lice, ticks)
 Rocky Mountain Spotted Fever

Tick-borne diseases
Rocky Mountain Spotted Fever
(Rickettsiae)
 Tularemia (Bacteria)
 Babesiosis (Protozoa)
 Lyme Disease (Bacteria)
 Ehrlichiosis (Bacteria)

Chlamydiae


Very small, nonmotile
bacteria
Diseases include:



Nongonococcal
urethritis
Inclusion conjunctivitis
Picture of inclusion
conjunctivitis
Mycoplasmas
Very small bacteria that lack a cell wall
 Diseases include:


Primary atypical pneumonia
Electron micrograph of thin-sectioned
mycoplasma cells
Viruses
Small infectious pathogen that relies on
other living cells to complete life cycle.
Three main type of viruses exist: DNA,
RNA, and incomplete or defective
 Diseases include:

Cold/Flu
 Chicken Pox
 AIDS
 Measles

Small Pox (eradicated)
Hemorrhagic Fevers
-Ebola
-Lassa Fever
Small Pox and Chicken Pox
Human Defense Mechanisms Against
Viruses

Formation of Interferon

Interferon is a nonspecific antiviral agent
induced by viruses. Produced mainly by
monocytes and lymphocytes
Humoral Cell Response
 Cell-Mediated Response

Diseases Targeted for Eradication
World Health Organization (WHO)
 Small pox (since 1973)
 Polio
 Drancunculiasis (Guinea Worm)
 Leprosy
Fungi
Plantlike organism that vary
in size and number of cells
 Two types of fungal
diseases:


Athlete’s foot fungus
Superficial (skin) infections
 Athlete’s
feet
 Ringworm

Systematic infections
Ringworm fungus
Fungi

Systematic Infections
Histoplasmosis
 Blastomycosis
 Coccidiodomycosis

These diseases can infect a persons heart,
lung, and central nervous system
Protozoa


Single-celled microscopic animal forms that
release toxins and enzymes that interfere with
bodily functions.
Diseases include:







Dysentery (vehicle-water)
Malaria (vector-mosquito)
African Sleeping Sickness (tsetse fly)
Chagas (reduviid bug)
Giardiasis (vehicle-water)
Toxoplasmosis (reservoir-cat)
Leishmaniasis (vector-sand fly)
Metazoa

Multicellular organisms such as tapeworms,
ringworms, and flukes.

Diseases include:
 Trichinosis
 Pinworm
 Tapeworm
 Lymphatic Filiarisis (Elephantiasis) vectormosquito
 Drancunculiasis (Guinea Worm) vehicle-water
Tapeworm & Elephantiasis
Bioterrorism Diseases
Small pox
 Tuleremia
 Anthrax
 Plague
 Botulism (Toxin)

Current World Health Problems
Morbidity
1.
2.
3.
4.
5.
Diarrhea
Respiratory infections
Occupational injuries
Chlamydia
Trichomoniasis
Number
1821 million
248 million
120 million
97 million
94 million
Current World Health Problems
Morbidity (2nd top 5)
6.
7.
8.
9.
10.
Gonococcal Infections
Occupational Diseases
Measles
Whooping Cough
Genital Warts
Number
78 million
69 million
45 million
43 million
32 million
Current World Health Problems
Disability
1.
2.
3.
4.
5.
Mood Disorders
Lymphatic Filariasis
Hearing Loss
Mental Retardation
Cataract-related Blindness
Number
59 million
43 million
42 million
41 million
16 million
Current World Health Problems
Disability (2nd top 5)
6.
7.
8.
9.
10.
Epilepsy
Dementia
Poliomyelitis
Schizophrenia
Obstructed Labor
Number
15 million
11 million
10 million
8 million
7 million
Section D: Chronic
Diseases
Dr. Jones
University of Arkansas
Human Disease
Chronic Diseases
Definition
 Illnesses that are prolonged, do not
resolve spontaneously, & are rarely cured
completely
Chronic diseases that are a focus of
prevention efforts are those that are
preventable & pose a significant burden in
mortality, morbidity, & cost
Chronic Diseases & Conditions
Major Diseases
 Alzheimer’s Disease = 4 million
 Arthritis = 69 million
 Cancer = 8 million
 Cardiovascular Disease = 58 million
 Chronic Obstructive Pulmonary Disease =
30 million
Chronic Diseases & Conditions
Major Diseases
 Diabetes =20 million
 Epilepsy = 2.3 million
 Iron Overload = 1 million
 Oral Diseases & Conditions = ??
 Osteoporosis = 28 million
Age-adjusted death rates for selected leading causes of death: United States,1958-2005
ICD-7
ICD-8
ICD-9
ICD-10
1-diseases of the heart
1000.0
2-malignant neoplasms
3-cerebrovascular diseases
100.0
5-unintentional injuries
9-nephritis, nephrotic syndrome
and nephrosis
10.0
13-Hypertension
14-Parkinson’s
1.0
7- Alzheimer’s
0.1
1958 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005
Numbers indicate ranking of conditions as leading causes of death in 2005. (ICD stands for International Classification of Diseases)
NOTE: Age-adjusted rates per 100,000 U.S. standard population, see “Technical Notes.”
SOURCE: CDC/NCHS, National Vital Statistics System, Mortality.
Cardiovascular Disease
A general term to describe many heart
disorders, including high blood pressure,
coronary artery disease, & clogging of the
arteries (arthrosclerosis).
 Number one cause of death in the United
States (CDC) and worldwide (WHO)

Cardiovascular Disease
Congenital
 Valvular
 Coronary
 Hypertension (high blood pressure)
 Primary Myocardial

Congenital Heart Disease
The heart fails to develop normally from
the prenatal to 1 year period of a person’s
life.
 Causes: virus, chromosomal
abnormalities, or unknown
 Prevention: protection of fetus from
interuterine injury

Congenital Heart Disease

Primary Types:
Septal defects
 Obstruction defects (stenosis)
 Cyanotic defects
 Hypoplastic

Valvular Heart Disease
Scarring or malfunction of heart valves
(mainly mitral & aortic)
 Causes: bacterial infections, degenerative
processes, IV drug abusers
 Treatment: prevention of Rheumatic
Fever & other bacterial infections

Valvular Heart Disease
Dysfunctions of valves
 Stenosis-hardening or calcification of valves
that prevents valves from fully closing.

Prolapse (floppy valve)-valves are enlarged
and attached cords become long and allows
blood to flow in the opposite direction back
into the chamber.
Valvular Heart Disease
Valves can become damaged by:
Pregnancy
 Fever, infection
 Changes due to aging

Coronary Heart Disease


Diseases resulting from the
arteriosclerosis of the large coronary
arteries.
Arteries become:
Narrowed due to the accumulation of lipids
(fat & cholesterol)
&
2) Weak & brittle due to degeneration
1)
Another view
Coronary Heart Disease

Possible causes
Elevated blood lipids
 High blood pressure
 Smoking
 Diabetes
 Personality
 Obesity

Results of Myocardial Ischemia
(Loss of Blood Flow)
Coronary Thrombosis
Hemorrhage in plaque
Coronary arterial spasm
Increased myocardial oxygen requirements
Cardiac Arrest
Myocardial
Infarction
Myocardial Infarction
1.
2.
3.
4.
5.
6.
7.
Disturbance of cardiac rhythm
Heart failure
Cardiac rupture
Intracardial thrombi
Pericarditis
Papillary muscle dysfunction
Ventricular aneurysm
More realistic view

As in prior picture,
heart muscle death
would be taking place
in area of thrombosis
Coronary Heart Disease
Treatment Procedures
 Medical Treatment
Medication
 Smoking cessation
 Control of Hypertension

Surgical Treatment
 Coronary Angioplasty/Catheterization

Cost for Treatment
Cardiac Catheterization - $20,000
 Angioplasty - $20,370
 Open Heart - $253,000
 Bypass - $44,000
 Transmyocardial Revascularization - ?

Hypertensive Heart Disease

Excessive vasoconstriction of the small
arterioles throughout the body, thus raising
diastolic blood pressure.

Measured by taking the systolic blood
pressure (arteries) over the diastolic blood
pressure (ventricles).
Hypertensive Heart Disease


Effects
 Cardiac
 Vascular
 Renal
Causes


In most cases it is
unknown
Treatment

medication
Primary Myocardial Disease

Disease of the heart muscle

Two types:
Myocarditis
 Cardiomyopathy

Primary Myocardial Disease
Myocarditis
 Inflammation of the heart muscle
associated with injury and necrosis of the
muscle fibers.
 Cause: viruses, parasites, fungi,
hypersensitivity
 Treatment: bed rest, treat the cause
This is your pericardium.
This is your pericardium with
myocarditis.
Heart Disease as Compared with
Mechanical Pump Dysfunction
Mechanical Abnormality
Faulty pump construction
Faulty unidirectional valves
Dirty or clogged fuel line
Overloaded pump
Malfunctioning pump
Heart Disease
Congenital
Valvular
Coronary
Hypertensive
Primary myocardial
Cerebrovascular Disease (Stroke)

Injury to the
brain tissue
resulting from
disturbance of
blood supply to
the brain
Cerebrovascular Disease (Stroke)

Three Classifications
Thrombosis (clot forms in the brain; most common)

Embolus (clot forms elsewhere, moves to brain)

Hemorrhage (most fatal)

Causes: Same as for CVD (cardiovascular disease)
Treatment: Rehabilitation


-Anti-clot busting drugs(TPA)
Prevalence of stroke by age* and sex
Percent of Population
16
14.8
14
12.4
12
10
8
6.5 6.2
6
4
2
0.5 0.5
1.2
2.3
0
20-39
40-59
Men
60-79
Women
*Note age categories are different than prior slide.
(NHANES: 1999-2004). Source: NCHS and NHLBI.
80+
Diabetes
Definition
 The inability of the body to produce or
respond properly to the hormone insulin.
The body needs insulin to convert glucose
(“blood sugar”) to energy. Diabetes is
defined as a fasting plasma glucose level
of 126 mg/dL or more measured on 2
different occasions.
Diabetes
Types
 Type I – insulin dependent (3 mil)
 Type II – non-insulin dependent (17 mil)
 Pre-diabetes (15 mil)
 Gestational
 Other causes
Diabetes
Complications
 Heart Disease
 Kidney Failure
 Blindness
 Lower/Upper Extremity Amputations
Diabetes
Treatment
 Changes in eating habits
 Weight management
 Exercise programs
 Medication
 Regular check-ups
Diabetes
Possible Cures
 Pancreas transplantation
 Islet cell transplantation
 Artificial pancreas development
 Genetic manipulation
Cancer
A group of diseases characterized by
uncontrolled growth and spread of
abnormal cells
 Induction time of cancer (exposure +
incubation) can be from 30 years or more
to less than 1 year
 Second leading cause of death in the
United States

The good news – Estimated
cancer survivors, 1971-2004
2008 Estimated US Cancer Cases*
Men
745,180
Women
692,000
Prostate
25%
26%
Breast
Lung & bronchus
15%
14%
Lung & bronchus
Colon & rectum
10%
10%
Colon & rectum
Urinary bladder
7%
6%
Uterine corpus
Non-Hodgkin
lymphoma
5%
4%
Non-Hodgkin
lymphoma
Melanoma of skin
5%
4%
Thyroid
Kidney & renal pelvis
4%
4%
Melanoma of skin
Oral cavity
3%
3%
Ovary
Leukemia
3%
3%
Kidney & renal pelvis
Pancreas
3%
3%
Leukemia
20%
23%
All Other Sites
All Other Sites
*Excludes basal and squamous cell skin cancers and in situ carcinomas except urinary bladder.
Source: American Cancer Society, 2008.
2008 Estimated US Cancer Deaths*
Lung & bronchus
31%
Prostate
10%
Men
294,120
Women 26%
271,530
15%
Lung & bronchus
Breast
Colon & rectum
8%
9%
Colon & rectum
Pancreas
6%
6%
Pancreas
Liver & intrahepatic
bile duct
4%
6%
Ovary
3%
Leukemia
4%
Non-Hodgkin
lymphoma
Esophagus
4%
3%
Leukemia
Urinary bladder
3%
3%
Uterine corpus
Non-Hodgkin
lymphoma
3%
2%
Liver & intrahepatic
bile duct
Kidney & renal pelvis
3%
2%
Brain/ONS
24%
25%
All other sites
ONS=Other nervous system.
Source: American Cancer Society, 2008.
All other sites
Lifetime Probability of Developing Cancer, Men, 2002-2004*
Site
Risk
All sites†
Prostate
1 in 2
1 in 6
Lung and bronchus
1 in 13
Colon and rectum
1 in 18
Urinary bladder‡
1 in 27
Melanoma
1 in 41
Non-Hodgkin lymphoma
1 in 46
Kidney
1 in 59
Leukemia
1 in 67
Oral Cavity
1 in 71
Stomach
1 in 88
* For those free of cancer at beginning of age interval.
† All Sites exclude basal and squamous cell skin cancers and in situ cancers except urinary bladder.
‡ Includes invasive and in situ cancer cases
Source: DevCan: Probability of Developing or Dying of Cancer Software, Version 6.2.1 Statistical Research and
Applications Branch, NCI, 2007. http://srab.cancer.gov/devcan
Lifetime Probability of Developing Cancer, Women, US, 2002-2004*
Site
Risk
All sites†
Breast
1 in 3
1 in 8
Lung & bronchus
1 in 16
Colon & rectum
1 in 19
Uterine corpus
1 in 41
Non-Hodgkin lymphoma
1 in 53
Melanoma
1 in 61
Ovary
1 in 71
Pancreas
1 in 76
Urinary bladder‡
1 in 85
Uterine cervix
1 in 142
* For those free of cancer at beginning of age interval.
† All Sites exclude basal and squamous cell skin cancers and in situ cancers except urinary bladder.
‡ Includes invasive and in situ cancer cases
Source: DevCan: Probability of Developing or Dying of Cancer Software, Version 6.2.1 Statistical Research and
Applications Branch, NCI, 2007. http://srab.cancer.gov/devcan
Cancer Survival*(%) by Race,1996-2003
Site
African
WhiteAmerican
Absolute
Difference
All Sites
67
57
10
Breast (female)
90
78
12
Colon
66
55
11
Esophagus
18
11
7
Leukemia
51
40
11
Non-Hodgkin lymphoma
65
56
9
Oral cavity
62
41
21
Prostate
99
95
4
Rectum
66
58
8
Urinary bladder
81
65
16
Uterine cervix
74
66
8
Uterine corpus
86
61
25
*5-year relative survival rates based on cancer patients diagnosed from 1996 to 2003 and followed through 2004.
Source: Surveillance, Epidemiology, and End Results Program, 1975-2004, Division of Cancer Control and
Population Sciences, National Cancer Institute, 2007.
Trends in Five-year Relative Survival (%)* Rates, US, 1975-2003
Site
1975-1977
1984-1986
1996-2003

All sites
50
54
66

Breast (female)
75
79
89

Colon
51
59
65

Leukemia
35
42
50

Lung and bronchus
13
13
16

Melanoma
82
87
92

Non-Hodgkin lymphoma
48
53
64

Ovary
37
40
45

Pancreas
2
3
5

Prostate
69
76
99

Rectum
49
57
66

Urinary bladder
74
78
81
*5-year relative survival rates based on follow up of patients through 2004.
Source: Surveillance, Epidemiology, and End Results Program, 1975-2004, Division of Cancer Control and
Population Sciences, National Cancer Institute, 2007.
http://statecancerprofiles.cancer.gov/map/map.noimage.php
http://statecancerprofiles.cancer.gov/map/map.noimage.php
Causes of Cancer

Exact cause is unknown

Multiple causes associated with cancer
may include life-style, and external and
internal factors
Causes of Cancer

Life-style factors include:


External factors include:


Nutrition, smoking, stress, and activity levels
Chemicals, radiation, viruses
Internal factors include:

Hormones, immune system, and inherited
mutations
Cancer Tumors (Neoplasms)
Two types:
1. Benign (non-cancerous)
2.
Malignant (harmful growth)
Which is which?
How Cancer Spreads

Infiltration-effecting nearby organ

Metastases – spreads through blood
vessels or lymphatic system
Colon cancer infiltration
The Metastasis Process
Cancer Tissue By Type
Lung adenocarcinoma

Carcinoma – Epithelium

Sarcoma – Connective
tissue
Soft tissue sarcoma
Cancer Tissue By Type


Melanoma – Skin
cells
Neuroblastoma –
Central Nervous
System
Large neuroblastoma behind liver
Types of Skin Cancer

Basal Cell (90%)

Squamous Cell

Melanoma (most serious)
Cancer Tissue By Type
Adenocarcinoma – Epithelium &
Endocrine gland tissue
 Hepatoma – liver
 Leukemia – blood cells
 Lymphoma – immune system and
lymphatic tissue

Grading and Staging of Cancer

Grading

Based on grades of I through IV, depending
on degree of difference from normal cells
Grading and Staging of Cancer

The American Joint Commission on Cancer has
recommended the following guidelines for
grading tumors:





GX – grade cannot be assessed
G1 – well differentiated
G2 – moderately well differentiated
G3 – poorly differentiated
G4 - undifferentiated
Grading and Staging of Cancer

Staging

Use of the TNM system
T
= primary tumor
 N = nodal involvement
 M = metastases
Grading and Staging of Cancer
Example for Rectal Cancer
Primary tumor (T)
TX: Minimum requirements to assess the primary tumor
cannot be met
TO: No evidence of primary tumor
Tis: Carcinoma in situ: intraepithelial or invasion of the
lamina propria*
T1: Tumor invades submucosa
T2: Tumor invades muscularis propria
T3: Tumor invades through the muscularis propria into the
subserosa or into the nonperitonealized pericolic or
perirectal tissues
T4: Tumor perforates the visceral peritoneum, or directly
invades other organs or structures**
Grading and Staging of Cancer
Example for Rectal Cancer
Regional lymph nodes (N)
NX: Minimum requirements to assess the regional nodes can be met
NO: No regional lymph node metastasis
N1: Metastasis in 1 to 3 pericolic or perirectal lymph nodes
N2: Metastasis in 4 or more pericolic or perirectal lymph nodes
N3: Metastasis in any lymph node along the course of a named
vascular trunk and/or metastasis to apical node(s) (when marked by
the surgeon)
Grading and Staging of Cancer
Example for Rectal Cancer
Distant metastasis (M)
MX: Minimum requirements to assess the
presence of distant metastasis cannot be met
MO: No distant metastasis
M1: Distant metastasis
7 Warning Signs of Cancer
Change in bowel or bladder habits
 A sore that does not heal
 Unusual bleeding or discharge
 Thickening or lump in breast or elsewhere
 Indigestion or difficulty swallowing
 Obvious change in a wart or mole
 Nagging cough or hoarseness

Cancer Treatment





Surgery
Radiation
Chemotherapy
Anti-cancer drugs
Any combination of the
above
Promising Cancer Treatments





Immunotherapy
Vaccines
Gene/hormone
Therapy
Bone Marrow
Transplantation
Drug Delivery
Systems
Disease Screening

Purpose

To identify people who have an enhanced
probability of receiving a disease and have no
signs or symptoms of the disease. A
screening test is not intended to be
diagnostic.
Disease Screening

Outcomes
True-Positive – individual has the disease &
is screened with the disease
 True-Negative – individual does not have
disease & is screened without the disease
 False-Positive – individual does not have
disease but is screened positive
 False-Negative – individual has the disease
but is screened negative

Disease Screening

Definitions

Sensitivity – the ability of a screening tool to
detect individuals with the disease

Specificity – the ability of a screening tool to
detect individuals without the disease
Sensitivity vs. Specificity
A
B
C
Non-diseased
Diseased
Disease Screening

Types of Screening Tools
Mammography
 Pap Smear
 PSA
 Cholesterol
 Blood Pressure
 Blood Sugar
