$$\text{Morbidity Rate} = \frac{\text{Number of people affected}}{\text{Total population}} \times 100$$

Question 1

Which of the following best describes the relationship between normal microbiota and the human host in which both organisms benefit?

Accepted Answer

Mutualism

Question 2

A patient is infected with a bacterium that cannot be cultured in laboratory media. Which of Koch’s postulates cannot be fulfilled in this case?

Accepted Answer

The pathogen must be isolated and grown in pure culture.

Question 3

Which of the following is an example of microbial antagonism?

Accepted Answer

Normal microbiota produce acids that inhibit the growth of pathogens.

Question 4

A disease that is constantly present in a population, such as malaria in certain regions, is classified as:

Accepted Answer

Endemic

Question 5

Which of the following best describes a nosocomial infection?

Accepted Answer

An infection acquired as a result of a hospital stay

Question 6

A patient develops a secondary infection after being treated for influenza. This secondary infection is most likely caused by:

Accepted Answer

An opportunistic pathogen taking advantage of the weakened host

Question 7

Which of the following is the correct formula for calculating the morbidity rate?

Accepted Answer

$$	ext{Morbidity Rate} = \frac{	ext{Number of people affected}}{	ext{Total population}} 	imes 100$$

Question 8

Which of the following is an example of vehicle transmission?

Accepted Answer

Drinking contaminated water

Question 9

A disease that spreads rapidly to many people in a given area in a short time is called:

Accepted Answer

Epidemic

Question 10

Which of the following is NOT a predisposing factor for disease?

Accepted Answer

Having a strong immune system

Question 11

Which of the following best describes a latent disease?

Accepted Answer

A disease with a period of no symptoms when the causative agent is inactive

Question 12

Which of the following is the correct sequence for the development of disease?

Accepted Answer

Incubation period → Prodromal period → Period of illness → Period of decline → Period of convalescence

Question 13

Which of the following is an example of indirect contact transmission?

Accepted Answer

A person touching a contaminated tissue and then touching their mouth

Question 14

Which of the following is a major contributing factor to emerging infectious diseases?

Accepted Answer

Genetic recombination

Question 15

A patient is diagnosed with septicemia. Which of the following best describes this condition?

Accepted Answer

Growth of bacteria in the blood

Question 16

Which of the following is the best example of a zoonosis?

Accepted Answer

Rabies transmitted from a dog to a human

Question 17

Which of the following is the correct formula for calculating prevalence?

Accepted Answer

$$	ext{Prevalence} = \frac{	ext{Number of total cases}}{	ext{Total population}} 	imes 100$$

Question 18

Which of the following is a sign, rather than a symptom, of disease?

Accepted Answer

Fever of 39°C

Question 19

Which of the following is the most common cause of nosocomial infections in hospitals?

Accepted Answer

Clostridium difficile

Question 20

Which of the following best describes herd immunity?

Accepted Answer

Immunity in most of a population

Principles of Disease and Epidemiology: Study Notes

Study Guide - Practice Questions