Deck 2: Basics of Infectious Disease Epidemiology

Question 1

Infectivity is:

A) the amount of pathogen required to produce an infection.
B) the ability of a pathogen to produce an infection.
C) only caused by viruses.
D) the same as infertility.

Answer 1

B

Question 2

The incubation period is:

A) the time during which an individual displays the signs and symptoms of an infectious illness.
B) the time between exposure to the pathogen and appearance of signs and symptoms in an individual.
C) the time it takes to culture an organism in the laboratory.
D) the time it takes between first contact with a diseased individual for a second susceptible individual to display signs and symptoms.

Answer 2

B

Question 3

Pathogenicity:

A) refers to the degree of harm caused by an organism to a host.
B) requires laboratory tests to verify its presence.
C) the ability of an organism to cause a disease (or not).
D) the same as virulence.

Answer 3

C

Question 4

Virulence is:

A) the degree of damage caused by a microorganism to a host.
B) a term only used in the context of viral infection.
C) applied only to human infections.
D) the same as pathogenicity.

Question 5

Consider the following: the common cold and the Ebola virus.
Which is/are pathogenic?

Question 6

In Question 5, which disease is more virulent?

Question 7

Which of the following could normally be considered chronic infections? Choose all that apply.

A) Strep throat
B) AIDS
C) Meningitis
D) COPD

Question 8

Which one of the following is the best possible definition of sensitivity?

A) The number of those individuals for whom a test result is positive divided by the total number of individuals in a sample which the gold standard test has given a positive result
B) How well a test selects those who have the disease
C) The number of positives in the sample divided by the total number of participants
D) How well a test selects those who do not have the disease

Question 9

A definition of specificity is:

A) The proportion of true negatives indicated by the test result divided by the total number of negatives indicated by the gold standard test
B) The probability of finding a negative in the general population
C) How well a test selects a condition
D) A diagnostic test that diagnoses a condition

Question 10

Which of the following is true in terms of the number of patients involved?

A) outbreak > pandemic > epidemic
B) outbreak = pandemic = epidemic
C) epidemic > pandemic > outbreak
D) pandemic > epidemic > outbreak

Question 11

A latency period is defined as:

A) the interval between exposure and clinical signs.
B) how long an organism remains in the body.
C) the interval between exposure and infectiousness.
D) the period during which the organism is not infectious.

Question 12

The incubation period is:

A) the interval between the point of infection and clinical disease.
B) always the same as the latency period.
C) how long it takes to culture the organism in the laboratory.
D) how long it takes the population of organisms to double.

Question 13

Prevalence takes into account only new cases in a population during a given period of time.

Question 14

Incidence takes into account only existing cases in a population during a given period of time.