Epidemiology: Introduction, History, & Definitions (1)

Question 1

What is epidemiology?

Answer 1

the study of what is upon people

• it used to only apply to human populations
  (hence, demos meaning people)

epi: means upon

Question 2

What is the LMU epidemiology definition?

Answer 2

the study of the health of populations

Question 3

What is one health?

Answer 3

the collaborative efforts of multiple disciplines working locally, nationally, and globally, to attain optimal health for people, animals and our environment

Question 4

What are the great epidemiology detective cases?

Answer 4

5 Ws and 1 H

Question 5

Who is John Snow?

Answer 5

English anesthesiologist who innovated several of the key epidemiological methods that remain valid and in use today

believed that cholera was transmitted by contaminated water and was able to demonstrate this association

Question 6

What is the miasmatic theory of disease?

Answer 6

disease is transmitted by a miasm, or cloud, that clung low on the surface of the earth

hence, malaria for “bad air”

in Snow’s time

Question 7

What is Snow’s natural experiment?

Answer 7

Snow noted that during a later cholera outbreak in 1854, those residents served by the Lambeth Company had fewer cases of cholera than residents served by the other water company

Question 8

What is health?

Answer 8

a state of complete physical, mental, and social well-being

not merely the absence of disease or infirmity

Question 9

What is disease?

Answer 9

absence of health

a non-compensated perturbation of one or several functions of the host

pathological condition occurring a susceptible host

Question 10

What is a case definition?

Answer 10

standard set of criteria for deciding whether an individual has a particular health condition

Question 11

Why is a case necessary?

Answer 11

you don’t always know what is causing the symptoms you are seeing during an outbreak or epidemic

defines who is included (as a numerator) in an outbreak investigation

Question 12

A case definition is defined in terms of _____, ______, and _____

Answer 12

person
place
time

Question 13

A case definition can be _____

Answer 13

sensitive
specific
influenced by number of cases

Question 14

Human rabies is a ______

Answer 14

clinically compatible illness laboratory confirmed by…

Question 15

What is the case definition for Ebola Zaire?

Answer 15

unexplained fever + contact with suspected patient
or unexplained fever + 3 of the following …
or unexplained acute hemorrhagic disease

Question 16

The graph shoes the number of AIDS cases reported as heterosexuality acquired in the US by years between 1981-1993. What happened in 1992-1993?

Answer 16

the case definition was changed and added the result of a laboratory test to the list of conditions which defined a case as AIDS

Question 17

What is the CDC’s definition of epidemic or outbreak?

Answer 17

the occurrence of more cases of disease than expected in a given area or among a specific group of people over a particular period of time

Question 18

T/F: An epidemic or outbreak is characterized by more than one case

Answer 18

FALSE - it can be a single case of a communicable disease long absent from a population

rabies, botulism, etc

Question 19

T/F: An outbreak is restricted to a single geographical area

Answer 19

FALSE - may occur in a restricted geographical area OR may extend over several countries

Question 20

What is a pandemic?

Answer 20

an epidemic that becomes very widespread and affects a whole region, a continent, or the world due to a susceptible population

Question 21

A true pandemic is associated with what?

Answer 21

high morbidity
significant mortality

Question 22

What is the attack rate equation?

Answer 22

of new cases in population at risk / # people in population at risk x 100

Question 23

What is crude mortality rate?

Answer 23

is the mortality rate from all causes of death for a population during a specified time period

Question 24

What is the denominator in crude mortality rate?

Answer 24

total population at the mid-point of time period

Question 25

What is case fatality rate?

Answer 25

the proportion of animals/persons with a particular condition who die from that condition

Question 26

What is the numerator in case fatality rate?

Answer 26

of deaths among those cases

Question 27

What is the denominator in case fatality rate?

Answer 27

number of incident cases

Question 28

What is cause-specific death rate?

Answer 28

the number of deaths from a specified cause per person/animal-years at risk

Question 29

What is the numerator for cause-specific death rate?

Answer 29

restricted to resident deaths in a specific geographic area (country, state, county, etc)

Question 30

T/F: Cause-specific death rate is very similar to case fatality rate but NOT the same

Answer 30

TRUE

Question 31

What is the iceberg dilemma of disease?

Answer 31

top: confirmed linked
bottom: at risk population

Question 32

What is the epidemiologic triad?

Answer 32

agent
host
environment

all encompassing disease