introduction to & fundamentals of epidemiology Flashcards
epidemiology
study of factors that determine the occurrence and distribution of disease in a popu
this understands:
how ppl get sick and die
who gets sick and dies
how to avoid getting sick
Epi - upon
Demos - people or population
Logos - discussion or study
epidemiology focuses on
Epidemics:
When a disease spreads rapidly to many people in a specific area or population at the same time.
Example: The COVID-19 outbreak in 2020 was an epidemic that became a pandemic (worldwide epidemic).
Other examples: Flu outbreaks in schools or workplaces
Infectious diseases (contagious or transmissible disease)
Examples:
Common cold (spreads through air and touch)
Chickenpox (spreads through air and direct contact)
Malaria (spreads through mosquito bites)
Chronic diseases (long-lasting disease)
Example:
Diabetes (affects blood sugar control)
Heart disease (affects the cardiovascular system)
Asthma (affects breathing)
Health-related diseases (disease or events that cause illness, death or disability)
Examples:
Injuries from car accidents
Health effects from air pollution
Food poisoning outbreaks
Mental health conditions
Portion of the population who has illness/ disease.
distribution
Factors that influence the problem.
determinants
differences between determinants and distribution
Distribution is the “WHO and WHERE” of the problem
Determinants are the “WHY and HOW” of the problem
who discovered pasteurization (the killing of microbes from materials, in his instance milk) and discovered The Germ Theory.
Louis Pasteur
who discovered many critical
forms of bacteria that were the
causative agents to many
then-ever-present diseases (examples)
Robert Koch
(tuberculosis, anthrax and cholera)
he is the founding fathers
of bacteriology.
Robert Koch
but he did not discover the bacteria. Anton van Leeuwenhoek discovered the bacteria.
Anton van Leeuwenhoek:
Louis Pasteur:
Robert Koch:
Anton van Leeuwenhoek: He was the first to see bacteria through a microscope
Louis Pasteur: He figured out how to kill harmful germs in milk (this is why we call it pasteurization)
Robert Koch: He proved that specific germs cause specific diseases
chain of causation
infectious agent > reservoir > portal of exit > mode of transmission > portal of entry > susceptible host
this is the microorganism (germ or bug) that can cause harmful infections and make you ill.
infectious agent:
(colds, flu, stomach bugs like norovirus and clostridiodes. difficile)
this is where the germ lives and grows
reservoir:
- human R
- animal R
- environmental R
this is the person who is at risk of infection because they are unable to fight the infection
susceptible host
*elderly ppl can have decreased immune systems and catch infectious easier
Defined as the cause or origin of a
disease or abnormal condition
etiology
* asks the question: “Is the disease due to genetics, lifestyle factors, radioactive interventions, etc.?”
what are the risk factors of etiology
they are characteristics or factors associated with disease development
- Nonmodifiable
(e.g. age, race, sex)
for example: Dark people have more melanin in the skin than lighter people. Hence, they are not prone to skin cancer. As they have more melanin that act like a shield.
- Modifiable
(e.g. frequency of smoking, exposure to radiation)
Is the study of how disease progresses in the absence of medical or public health intervention.
Natural history of disease
briefly explain the stages of natural history of diseases
- pre disease stage
- before exposure to D - latent stage (preclinical stage or incubation period)
- D process has started, present in the human body
- but show no signs and symptoms - symptomatic stage (clinical period)
- D manifestations are evident
levels of prevention
primary prevention:
prophylaxis, vaccines
secondary prevention:
vaccines
tertiary prevention:
medications, surgeries, therapies
signs vs symptoms
signs:
empiric measurement - measurable
(urine, temp, levels of bp)
symptoms:
not measurable but can feel
(body ache, headache, nausea)
when you are susceptible but do not have disease
stage of susceptibility
you have the disease but not manifesting
exposure
what are the types of clinical stage
nonclinical:
have the D but not showing any symptoms
v rare instances
subclinical:
no symptoms will ever be present (genetic malformanities, syndromes)
these includes their resistance and it is influenced by … (examples)
host
examples:
genetics
nutritional status
BMI
immune system
social behaviour
Are the causative microorganisms/microbes that bring about a disease
Agents:
- biological
- allergens
- infectious organism (bacteria, virus)
- food
- have direct influence in the body
- chemical
- chemical toxins and dusts - physical
- kinetic energy (movement)
- temp
- radiation
- noise
- physical trauma - social and physiological
- raised enviro
- immediate social and familial circle
- exposure to media
- physiological trauma
The physical, chemical and biological factors that exist outside of the body and affect human health.
environment
*More often, it is the usual locale of the host
A carrier of a disease-causing agent from an infected
individual to a non-infected individual or its food or environment.
vector
causative factors vs risk factors
similarities and differences
similarities:
include a wide array of elements that influence a person’s susceptibility to a specific disease.
difference:
CAUSATIVE FACTOR (1:1)
- direct causes
- are causative in nature
(smoking for lung cancer, unhealthy diet for obesity, allergens for anaphylactic shock)
RISK FACTOR
-characteristics or occurrence that is associated with an increased rate of a disease
- not necessarily the sole cause of the disease
- correlational in nature
(age for measles, obesity for gynecological cancer, sex for breast cancer )
epidemiological triangle
traditional epidemiologic triangle:
- host
- environment
- agent/ vector
modern epidemiologic triangle:
- causative factors
- risk factors
biological
physiological
sociocultural
environmental
cultural
behavioral
ecological
- groups of population
TIME: it takes time for the D to manifest/ develop
this shows how disease happens through the interaction of agent, host and environment
traditional epidemiological triangle
what has to be considered in the modern epidemiologic triangle
Causative factors have to be considered in relation to the risk factors and groups of population.
what does the modern epidemiological triangle focuses on
grps of ppl and
diff factors tht lead to disease, rather than an indiv
who made the BEINGS model
Mervyn Susser
a South African epidemiologist, activist and doctor who was a pioneer in epidemiology
He is one of the founding fathers of epidemiology
BEINGS Acronym for categories of preventable cause of disease
biological and behavioral factors
environmental factors
immunological factors
nutritional factors
genetic factors
services, social and spiritual factors
The normal occurrence of a disease or condition common to persons within a specified area.
endemic
Refers to a disease or condition that affects a greater than expected (or normal) number of individuals within a population, community or region at the same time
epidemic
- sudden increase in cases spreading through a large population
Upper end of the normal endemic level of infections.
epidemic threshold
An epidemic that has become geographically widespread
pandemic
endemic:
epidemic:
epidemic threshold:
pandemic:
endemic: “normal” or expected amt of cases in an area
epidemic: more cases than normal in one area, sudden surge
epidemic threshold: “warning line”, border btwn normal and concerning
pandemic: an epidemic that spreads to many countries
it is a disease caused by lack of nutrition (particularly niacin or vitamin B3) directly inked to malnutrition
pellagra
o causes redness to skin and scaling and also neurologic changes
o thought to be caused by germs and is transmissible (especially between prisoners) before Goldberger’s discovery
who discovered pellagra
Joseph Goldberger
a Hungarian doctor
o injected blood from “infected” people to his own bloodstream and then found that pellagra was not infective
o had prisoners volunteer to participate in his study with a promise of early release
o conducted years before ethical guidelines were established, but he did allow prisoners who volunteered to receive benefits for their participation
An experiment wherein black men were subjected to be trial subjects for the search of the cure of syphilis in exchange of “free medical care”. Although the cure was discovered in 1947, 15 years after the beginning of the trials, they still were given the proper treatment and were still only given placebo.
Tuskegee Syphilis Experiment (1932)
Mentally retarded children housed at the Willowbrook State School in Staten Island, New York, were intentionally given hepatitis in an attempt to track the development of the viral infection.
Willowbrook Human Experiment (1956)
Who injected live, cultured cancer cells into the bodies of 22 debilitated patients at the Jewish Chronic Disease Hospital (JCDH) in Brooklyn, New York. The purpose of the research was to determine whether the previously established immune deficiency of cancer patients was caused by their cancer or, alternatively, by their debilitated condition.
Jewish Chronic Disease Hospital Study (1963)
Chester M. Southampton is responsible for the study while Deogracias B. Custodio is the assistant.
summary:
Tuskegee Syphilis Experiment (1932) -
Willowbrook Human Experiment (1956) -
Jewish Chronic Disease Hospital Study (1963) -
Tuskegee Syphilis Experiment (1932) - black men, syphilis
Willowbrook Human Experiment (1956) - mentally retarded children, hepatitis
Jewish Chronic Disease Hospital Study (1963) - 22 patients at Jewish Chronic Disease Hospital, live cultured cancer cells
it is one of the leading works concerning ethics and health care research.
The Belmont Report
a 1978 report created by the National Commission for the Protection of Human Subjects of Biomedical and Behavioral Research.
the primary purpose of the Belmont Report
to protect subjects and participants in clinical trials or research studies
- one of the leading works concerning ethics and health care research
what are the elements, components and application of the Belmont Report
RESPECT FOR PERSONS
- autonomy
- protection for those with diminished autonomy (those who cannot think straight - under the influence of drugs or alcohol)
BENEFICENCE
- do no harm
- maximize benefits, minimize harm
JUSTICE
- those who will receive the benefits of research shld share its burden
who mandated the requirement for the completion of training in research ethics
National Institutes of Health (NIH)
what are the ethical and practical obligations
- Risks to study participants are minimized.
- Risks are reasonable in relation to anticipated benefits.
- Selection of study participants is equitable. (respect for persons, benefiance, justice)
- Informed consent is obtained and documented for each participant.
- Adequate monitoring of data is required to ensure safety of study participants.
- Privacy of participants and confidentiality of data are protected.
the confidential aspects of all data collected should be spelled out in “informed consent” that the subject reads, signs and gets a copy of
confidentiality
fabrication and falsification of data, plagiarism, misconduct in authorship and research bias are punishable by law
research misconduct
briefly explain the uses of epidemiology
- investigating epidemics and new diseases
- studying the biological spectrum of disease
- surveillance of community health interventions
- setting disease control priorities
- improving diagnosis, treatment and prognosis of clinical disease
sociocultural vs cultural
- Sociocultural – society an individual is formed under
- Cultural – ethnicity, country, or race
an illustration be a diphtheria epidemic in albama
iceberg phenomenon
What tools and methods do clinical epidemiologists often use?
Research designs and statistical tools similar to those used by classical epidemiologists.
What is the focus of classical epidemiology?
It is population-oriented and studies the community origins of health problems, including infectious agents, nutrition, the environment, human behavior, and the psychological, social, economic, and spiritual state of a population.
How does clinical epidemiology differ from classical epidemiology in its focus?
Clinical epidemiology focuses on studying patients in health care settings, while classical epidemiology focuses on the community at large.
What is the primary goal of clinical epidemiology?
To improve the prevention, early detection, diagnosis, treatment, prognosis, and care of illness in individual patients at risk for or already affected by specific diseases.
How do epidemiologists contribute to investigating epidemics and new diseases?
They provide initial hypotheses about disease causation, suggest probable types of agents, and develop models of disease transmission for further testing.
What is the biological spectrum of disease, and how do epidemiologists study it?
It refers to the range of disease presentations, from asymptomatic to severely symptomatic. Epidemiologists record data to improve treatment and prognosis.
How do epidemiologists evaluate new vaccines before community-wide use?
Through randomized field trials of preventive measures as part of community health intervention surveillance.
What factors should be considered when setting disease control priorities?
Current size of the problem.
Potential for disease spread.
Likelihood of causing death and disability.
Economic cost to individuals, families, and the community.
How does epidemiology improve clinical medicine?
By applying epidemiologic methods to improve diagnosis, therapy, and prognosis of clinical diseases, which is the domain of clinical epidemiology.
