Chap 3: Epidemiology: The Study of Disease, Injury, and Death in the Community Flashcards
- Concerned with the course of disease in an individual
patient
Primary Care Physician
– is a public health scientist, who is responsible for carrying out all useful and effective activities needed for successful epidemiology practice
Epidemiologist
GOALof _______: To limit disease, injury, and death in a community by intervening to prevent or limit outbreaks or epidemics of disease and injury
Epidemiologist
– study of the distribution and
determinants of health related
states or events in specified
population and the application of this study to control health problems
Epidemiology
Epidemiology is also known as
population medicine
Epidemiology
– scientific discipline
- Study
Epidemiology
– factors that influence the occurrence of disease and other health-related events
Determinants
Epidemiology
– anything that affects the well-being of a population
- Health-related states or events
- “Father of Medicine”
- Suggested the relationship between the occurrence of disease & the physical environment (300 B.C.)
Hippocrates
– Few advances in epidemiology –
Epidemics
(Plague, leprosy, smallpox, malaria, syphilis, yellow fever)
Spiritual Era
traced the cases to the docks where ships arrived from tropical ports (Philadelphia)
Dr. Benjamin Rush
*Discovered the yellow fever
mosquito, Aedes aegypti
Walter Reed
50 years after the yellow fever outbreaks, ______ became
epidemic in London, 1849.
cholera
*Removed pump handle (1849)
*Achieved goal in limiting disease
and deaths
Dr. John Snow
30 yrs. after cholera:
- “Germ theory of disease”
- Principle of pasteurization
Louis Pasteur
- 1883,
*discovered Vibrio cholerae
& many other bacteria
Robert Koch
3 Types of Epidemiology:
- Descriptive epidemiology
- Analytical epidemiology
- Experimental epidemiology
– Describes the distribution of health status in terms of: age, gender, race, geography, time
etc.
Descriptive Epidemiology
Assessing health status, health
problems, health needs through
collections & surveys
Descriptive Epidemiology
Disease Surveillance
* what (case definition)
* who (person)
* where (place)
* when (time), and
* how many (count)
Descriptive Epidemiology
– study of the determinants (causes) of health-related states or events
– Answers: why and how
Analytical Epidemiology
test hypotheses about relationships between health problems & possible risk factors, factors that increase that increase the probability of disease
Analytical Epidemiology
– Evaluate the effects of intervention
– Identify the cause of a disease
Experimental Epidemiology
Determine the effectiveness of a
vaccine, therapeutic drug, or surgical
procedure
Experimental Epidemiology
Objective of epidemiological
study:
- To obtain an estimate of an epidemiological measure
without ______________________.
The research question should state what we want to measure.
random or systematic error
How many are (becoming) diseased?
(occurrence)
Why are some diseased?
(causal effects, etiology)
How can we tell whether someone is diseased?
(diagnostics)
What can we do for the diseased?
(intervention effects)
How does the diseased fare?
(prognosis)
How does it feel to have the disease?
(patient experiences)
EPIDEMIOLOGIC TRIANGLE
* 3 components
Host
Agent
Environment
– any susceptible organism invaded by an agent
HOST
– the element that must be present in order for disease to occur
AGENT
– includes all factors –
physical, biological, or social – that inhibit or promote disease transmission
ENVIRONMENT
– Influenced by exposure, susceptibility or
response to agents
INTRINSIC FACTORS/risk factors
– prior to
infection/immunization
Active immunity
– maternal
antibodies, gamma
globulins
Passive immunity
AGENTS OF DISEASE: PINC
PHYSICAL AGENTS
INFECTIOUS AGENTS
NUTRITIVE ELEMENTS
CHEMICAL AGENTS
- Excess
- Deficiencies
NUTRITIVE ELEMENTS
- Poisons
- Allergens
CHEMICAL AGENTS
- Heat, Light, Ionizing Radiation
PHYSICAL AGENTS
- Parasites, Protozoa, Bacteria, Fungi, Viruses
INFECTIOUS AGENTS
- influence existence of the agent, exposure, orsusceptibility to agent
EXTRINSIC FACTORS
EXTRINSIC FACTORS: PSB
PHYSICAL
SOCIOECONOMIC ENVIRONMENT
BIOLOGICAL
– inanimate surroundings
PHYSICAL
– Occupation, urbanization and disruption
SOCIOECONOMIC ENVIRONMENT–
– living things around us
BIOLOGICAL
– cockroach, flies, plants, etc
PASSIVE HOST
– vectors
ACTIVE HOST
- Characteristic data & factors - not constant
Epidemiologic Data
To analyze epidemiologic data
– Organize data according to the variables of :
TIME
PERSON
PLACE
– refers both to the period of exposure to the source of infection & the period during which the illness occurred
TIME
̶Characteristics of the individual (exposed & contacted the infection)
PERSONS
̶Characteristics of the individual (exposed & contacted the infection)
PERSONS
Described in terms of inherent or acquired characteristics ( age, race, sex, immune status,
marital status)
PERSONS
Variables under PERSONS
Age
Sex & Occupation
- Single most useful variable in describing occurrence &
distribution of disease - Potential for exposure to a source of infection
- Level of immunity or resistance
- Physiologic activity at the tissue level.
AGE
Male : higher _______ rate;
Female: higher ________ rate
mortality
morbidity
Differ in pattern of behavior, activities, travel, occupation,
exposure to infection
* Activities (work, play, & customs)
* Circumstances (social,economic & environmental )
SEX & OCCUPATION
– Features, factors or conditions in the environment where the disease occurred
PLACE
– Geographic area described in terms of:
* Street , address, city, municipality, province,
region, country
– Urban / Rural Differences
– Socio-economic areas
PLACE
Patterns of Disease Occurrence & Distribution
- Sporadic Diseases
- Endemic Diseases
- Epidemic Diseases
- Pandemic Diseases
- Epizootics
- Epizoodemic
̶ Intermittent occurrence of a few isolated &
unrelated cases in a given locality
Ex. Rabies (cases scattered throughout the country)
Sporadic Diseases
– a disease that occur regularly in a population with the usual number of cases in a given
locality
– Ex. Schistosomiasis in Leyte & Samar, Filariasis in Sorsogon
Endemic Diseases
: persistently high level of occurrence (endemic)
Hyperendemic
– an unexpectedly large number of cases of disease in a particular population in relatively short period of time
– More acute and serious problem
– Ex. Bird Flu
Epidemic Diseases
– an outbreak of disease over a wide geographical area such as a continent
– World-wide occurrence
– influenza pandemic of 1918-1919 killed 25 million people worldwide
Pandemic Diseases
– Disease outbreaks in animal populations
– Ex. Bubonic plague, St. Louis encephalitis (but later become epidemics)
– epizootiologist
Epizootics
– Disease outbreaks involving both animals and humans
Epizoodemic
