Epidemiology

Question 1

Time-Space clustering

Answer 1

distribution of disease occurs in patterns in a community

Question 2

Patterns of disease is

Answer 2

predictable

Question 3

Characteristics of the disease patterns may lead to

Answer 3

prevention or control of disease

Question 4

Epidemiologic Triad

Answer 4

Host - Agent - Environment; all 3 must be present and favorable for an infection to occur

Question 5

Host factors

Answer 5

biological traits (genetics, sex, age, ethnicity), social traits (behavior, nutrition, lifestyle, residence)

Question 6

Agents of disease

Answer 6

biological, chemical, nutritional, physical, energy

Question 7

Pathogenicity

Answer 7

ability to produce disease in a host

Question 8

virulence

Answer 8

to what extend can a pathogen cause disease (genetic, biochemical, structural)

Question 9

The outcome of an infection is determined by

Answer 9

the virulence of the pathogen and the resistance of the host

Question 10

vectors

Answer 10

biological means of spreading disease (insect)

Question 11

fomite

Answer 11

mechanical means of spreading disease (toilet seat)

Question 12

Herd Immunity

Answer 12

the spread of communicable disease within a group based on the proportion of susceptible and immune individuals

Question 13

What proportion of the population must be immune to maintain herd immunity?

Answer 13

dependent on the disease and the mode of transmission, higher for respiratory modes of transmission

Question 14

Physical factors

Answer 14

location of reservoir (where agent thrives), biologic factors (presence of arthropod/vector), mechanical vector (on feet of flies), biological vector (ticks), social factors

Question 15

Endemic

Answer 15

disease of humans present in a particular region at essentially constant levels

Question 16

Epidemic

Answer 16

sudden increase in the incidence of a particular disease

Question 17

Common source epidemic

Answer 17

all individuals are expose to pathogens from one common source

Question 18

Point source epidemics

Answer 18

all individuals are exposed to a pathogen during one point in time

Question 19

Propagative epidemics

Answer 19

serial transmission of an agent

Question 20

Pandemic

Answer 20

pandemics at a large scale (worldwide)

Question 21

Primary prevention

Answer 21

preventing disease before it occurs (sunscreen)

Question 22

Secondary prevention

Answer 22

catching a disease early (removing suspicious lesion)

Question 23

Tertiary Prevention

Answer 23

treating person with disease to get them healthy quicker

Question 24

Incidence

Answer 24

number of new cases reported during a specific time period (communicability and incubation time)

Question 25

Incidence rate

Answer 25

number of new cases with in a population in a defined time period / number of persons exposed in the same time period

Question 26

Incidence rates can be used to estimate

Answer 26

frequency (communicability) and incubation time

Question 27

Frequency

Answer 27

communicability; rate of disease transmission/time period

Question 28

Incubation period

Answer 28

time from exposure to time of onset of symptoms

Question 29

Incidence is

Answer 29

time dependent

Question 30

Attack rate

Answer 30

number of people ill / number of persons exposed during an outbreak

Question 31

Primary case

Answer 31

first case of disease in population

Question 32

index case

Answer 32

first case brought to attention of epidemiologists

Question 33

Secondary attack rate

Answer 33

percentage of people among close contacts of primary case who become ill

Question 34

Prevalence

Answer 34

incidence (new cases) + old cases

Question 35

Prevalence gives information about

Answer 35

the percent of disease in a population at one time; does not confer information about incubation period, rate of disease transmission, frequency of occurence

Question 36

What number directly impacts the predictive value of diagnostic tests

Answer 36

prevalence

Question 37

point prevalence

Answer 37

amount of disease present in a population at a time point (1300 TB cases / 130000 population = 1%)

Question 38

Point prevalence is helpful to

Answer 38

compare points of time, is prevalence increasing or decreasing

Question 39

Period prevalence

Answer 39

the number of people with the disease within the given time frame / population

Question 40

Factors that increase the prevalence rate

Answer 40

immigration of ill people or potentially exposed people, emigration of healthy people, increased incidence, increased duration of disease

Question 41

Prevalence is decreased by

Answer 41

increased death rates, shorter duration of disease, ill exiting, health entering

Question 42

If point prevalence AND incidence increase:

Answer 42

disease increases due to increased virulence or decreased treatment

Question 43

If point prevalence increases and incidence stays the same

Answer 43

recovery from disease slows, disease is less fatal ( anything that keeps ill people around longer)

Question 44

If point prevalence decreases and incidence stays the same

Answer 44

recovery from a disease speeds up or is more fatal (anything that takes ill people away faster)

Question 45

If point prevalence remains the same, but incidence drops

Answer 45

Prevention is occurring, but disease recovery is long-term

Question 46

If point prevalence remains relatively the same, but incidence is dropping significantly

Answer 46

Prevention of disease, but no cure (herpes)

Question 47

If point prevalence decreases and incidence decreases

Answer 47

spread of disease declines and recovery is permanent, disease is highly fatal

Question 48

Sensitivity

Answer 48

how good test is at picking up people who have this disease... True positive rate

Question 49

Specificity

Answer 49

how good this test is at at excluding people without the condition... true negative rate

Question 50

PPV

Answer 50

If test comes back positive, likelihood patient does have disease

Question 51

NPV

Answer 51

If test comes back negative, likelihood patient does not have disease