Epidemiology Exam 1

Epidemiology

the study of disease patterns in the environment genetics, and behaviors are studied and refined for health

descriptive epidemiology

describes the distribution of health related events (diseases) by case and characteristics. The knowledge gained is important for prevention and control activities

Characteristics of descriptive epidemiology

Person: Who Place: Where Time: When

analytic epidemiology

determines and measures the association between different exposures and different health related events

Purpose of analytic epidemiology

identify risk factors factors and causes for different diseases

efficacy

the ability of a program to produce a desired effect among those who participate vs those who did not

Effectiveness

The ability of a program to provide benefits among those who are offered the program

endemic

Persistent, usual, expected health-related state or event in a defined population over a given period of time

epidemic

Health-related state or event in a defined population above the expected over a given period of time

Pandemic

Epidemic affecting a large number of people, many countries, continents, or regions

common point source epidemic

1. common source (point, intermittent, continuous)

2. propagated: person to person

3. mixed: most common

epidemic curve of common point source

propagated epidemic

arise from infections transmitted from one infected person to another. person to person (epidemics rise and fall more slowly than common source) Examples: flu, tb, etc.

epidemic curve of propagated

primary case

the first disease case in the population

index case

the first patient found in an epidemiological investigation

suspect (possible) cases

may have signs and symptoms of disease but have not been diagnosed

probable case

As more info is avaliable, a clinical diagnosis may be made

confirmed case

when all the case criteria are met (lab results)

epi triangle

shows interaction and interdependence of agent, host, environment, and time as used in investigation of diseases and epidemics

agent

cause of the disease

host

an organism, usually human or animal that harbors a disease

environment

surrounding external organism that causes and allows disease transmission

time

accounts for incubation period, life expectancy of the host of the pathogen and duration of the course of the illness and condition

fomite

Any inanimate object to which infectious material adheres and can be transmitted. Ex: transmission of COVId-19 from a drink -indirect transmission

zoonosis

a disease that can pass from animals to humans Ex: Rabies, Lyme disease

Carrier

a person who is infected with a virus and who can pass it on to others but doesn't have clinical disease and no signs or symptoms

primary prevention

Actions that change overall background conditions to prevent some unwanted event or circumstance, such as injury, disease, or abuse. Ex: Immunization, sanitation, education

secondary prevention

Efforts to limit the effects of an injury or illness that you cannot completely prevent. Ex: Cancer screening

Tertiary Prevention

to reduce the limitation of disability from disease that has already occurred and is established Ex: Pt for stroke patients, fitness programs for heart attack patients

Hippocrates

first epidemiologist; earth, air, fire, water

Thomas Sydenham

Fever levels, persecuted for new treatments of fevers

James Lind

Experimental methods found remedy for scurvy

Benjamin Jesty

exposed his wife and children to cow pox to prevent them from getting small pox

Edward Jenner

Invented vaccine for small pox

Ignaz Semmelweis

Importance of hand washing to prevent disease

John Snow

Conducted descriptive and analytical studies on cholera

Louis Pasteur

Identified the cause of rabies; anthrax vaccine

Van Leeuwenhoek

Development of the use of the microscope

John Graunt

Systematic recording of mortality in London

William Farr

Developed a modern vital statistics system

Mary Mallon

Chronic carrier of typhoid fever, causing over 50 cases

Framingham Study

famous/extensive prospective cohort study that looked at cardiovascular disease in Massachusetts's

Doll and Hill

Case control and cohort studies showed an association between smoking and lung cancer

Etiology

cause of the disease and their mode of operation

vertical transmission

refers to transmission from an individual to its offspring through sperm, placenta, milk, or vaginal

horizontal transmission

refers to transmission of infectious agents from an infected individual to a susceptible contemporary

pathogen

Organisms/substances such as bacteria, viruses, or parasites that are capable of producing diseases

Acute disease

disorder with sudden onset, relatively severe, and short duration of symptoms

Chronic disease

less severe but of long/continuous duration, lasting over long time (6 months or more) periods if not lifetime

infectious disease

A disease that is caused by a pathogen and that can be spread from one individual to another.

communicable disease

a disease that is spread from one host to another

elements of disease flow chart

1. Point of exposure

2. pre symptomatic or subclinical disease

3. symptoms present meaning clinical disease

4. Stage of recovery, disability, or death (Time element involved)

Five categories of disease

1. Congenital and Heredity diseases

2. Allergies and inflammatory diseases

3. Degenerative diseases

4. Metabolic diseases

5. Cancer

3 Factors for reporting an outbreak (CDC and WHO)

1. causes serious morbidity or death

2. has the potential to spread

3. can be controlled with appropriate intervention (must have all 3!!)

Active immunity

the body produces its own antibodies. This can occur through a vaccine or in response to having a specific disease pathogen invade the body

passive immunity

is acquired through transplacental transfer of a mother's immunity from diseases to the unborn child

herd immunity

The resistance of a group to an attack by a disease to which a large proportion of the members of the group are immune (80% of population vaccinated)

Basic reproduction number

the average number of secondary cases produced by an infective person in a fully susceptible population

disease

An abnormal state in which the body is not functioning normally

imparement

a loss of function or ability

disability

any lost, absent, or impaired physical or mental function

Qualitative data

Information describing color, odor, shape, or some other physical characteristic (categorical data)

Quantitative data

Data associated with mathematical models and statistical techniques used to analyze spatial location and association. (continuous data)

displays for quantitative data

Frequency table, histogram, stem and leaf plot, dot plot, and box plot

displays for qualitative data

pie charts, bar graphs

Case report

involves a profile of a single individual, recognizes a conversational accounting of the signs/symptoms of a given patient

Case Series

involves a small group of patients with a similar diagnosis

ecologic study

mass exposure, mass surveying

The unit of analysis is a group not individual subjects, studying data on population level

cross-sectional study

A study in which a representative cross section of the population is tested or surveyed at one specific time.

Rates

relate directly to the risk, include time element

counts

relative to the population size

mortality rate

deaths occurring during a given time/ population from which the death occurred

incidence rate

new cases occurring during a given time period/ population at risk during the same time period

attack rate

new cases occurring during a short period time/population at risk at the beginning of the time period

crude rates

calculated for the entire population of interest and do not take into account differences that may be present in subgroups

adjusted rates

Statistical procedures applied to make crude rates more comparable

descriptive methods

case study survey naturalistic observation (DON'T SHOW CAUSE/EFFECT) collect person, place, and time

display of person characteristics

characterizes and describes who is getting the disease Ex: age, sex, race, occupation, marital status, education

Display of place

addresses where health related states or events are occurring and how frequent they are occurring

display time

can range from hours, weeks, years, and decades

temporal

time or refers to time related events or issues

marriage protection

married people have more economic resources, social and psychological support, and support for healthy lifestyles

Marriage Selection

healthier people being more likely to get married and stay married

healthy worker effect

observation that employed populations tend to have a lower mortality experience than the general population

Disease transmission by use of a shared needle is an example of

a. Direct Transmission b. Confirmed case c. Fomite d. Primary prevention

fomite

Characterizing the distribution of health-related states or events (according to person, place, and time) is

a. Descriptive epidemiology b. Analytic epidemiology c. Cohort study designs d. Case control study designs

Descriptive epidemiology

Epidemiology involves studying of only infectious communicable disease, not events like injury, obesity, mental health disorders, seat belt use, etc.

True False

False

A sharp and significant increase in a given disease is classified as an epidemic, especially if this type of increase is not anticipated.

True False

True

Outbreak of salmonella traced to chicken cooked and held at an improper temperature and served at a potluck supper is an example of a:

a. Common (Point) source epidemic b. Intermittent or continuous source epidemic c. Propagated epidemic d. Mixed epidemic

Common (Point) source epidemic

Public health surveillance involves all of the following except

a. Collection of health data b. Analysis of health data c. Interpretation of health data d. Dissemination e. It includes all of the above

It includes all of the above

Effectiveness of a program refers to which of the following:

a. The ability of a program to produce benefits among those who are offered the program b. The ability of a program to produce a desired effect among those who participate in the program compared with those who do not c. Both of the above d. Neither of the above

The ability of a program to produce benefits among those who are offered the program

The disease-causing pathogen is most commonly considered the agent.

True False

true

The primary cause of death in 1900 was

a. Cancer b. Heart disease c. Pneumonia and influenza d. Diabetes

c. Pneumonia and influenza

The epidemiologic triangle is based on the communicable disease model and is useful in showing the interaction and interdependence of certain factors. Which of the following best describes the Host?

a. Cause of the disease b. Harbors a disease c. Causes or allows disease transmission d. Duration

b. Harbors a disease

If you are the first person to contract a disease, then you are the ______________ case.

primary

Mammograms for early detection of breast cancer and surgical intervention if necessary is an example of.

a. Primary prevention b. Secondary prevention c. Tertiary prevention

b. Secondary prevention

Physical therapy for stroke victims is an example of.

a. Primary prevention b. Secondary prevention c. Tertiary prevention

c. Tertiary prevention

Education about the hazards of cigarette smoking is an example of.

a. Primary prevention b. Secondary prevention c. Tertiary prevention

a. Primary prevention

Typically the intervention focus inspired by the Triangle of Epidemiology infectious disease model is...

a. Surveillance and prevention b. Breaking one of the legs of the triangle c. Identification of the types of symptoms that characterize the disease d. Eliminating all three corners of the triangle

b. Breaking one of the legs of the triangle