$$\text{Incidence Rate} = \frac{\text{Number of new cases during a specific period}}{\text{Total population at risk during the same period}}$$

$$\text{Mortality Rate} = \frac{\text{Number of deaths from a disease}}{\text{Total population in a given period}}$$

Question 1

Which of the following best describes the relationship between E. coli in the large intestine and the human host, as shown in the provided image?

Accepted Answer

Mutualism: Both E. coli and the host benefit.

Question 2

During which stage of disease progression, as depicted in the graph, is a patient most likely to transmit an infectious disease to others?

Accepted Answer

Period of illness

Question 3

According to the pie chart, which type of healthcare-associated infection (HAI) is most prevalent in hospitals?

Accepted Answer

Gastrointestinal Clostridioides difficile infections

Question 4

Which of the following is an example of a noncommunicable disease?

Accepted Answer

Tetanus

Question 5

A patient develops a secondary infection after being treated with antibiotics for pneumonia. Which term best describes this scenario?

Accepted Answer

Opportunistic infection

Question 6

Which of Koch’s postulates would be violated if a pathogen cannot be grown in pure culture?

Accepted Answer

The pathogen must be isolated from the diseased host and grown in pure culture.

Question 7

Which of the following best explains why Clostridioides difficile infections are common in hospitals?

Accepted Answer

Antibiotic treatment reduces normal microbiota, allowing C. difficile to proliferate.

Question 8

Which of the following is a correct formula for calculating the incidence rate of a disease?

Accepted Answer

$$	ext{Incidence Rate} = \frac{	ext{Number of new cases during a specific period}}{	ext{Total population at risk during the same period}}$$

Question 9

A disease that is constantly present in a population, such as the common cold, is best described as:

Accepted Answer

Endemic

Question 10

Which of the following is an example of vehicle transmission?

Accepted Answer

A person contracting cholera from contaminated water

Question 11

Which of the following best describes herd immunity?

Accepted Answer

Immunity in most of a population, reducing disease spread

Question 12

Which of the following is a predisposing factor that can increase susceptibility to infectious disease?

Accepted Answer

Genetic inheritance

Question 13

Which of the following is an example of biological vector transmission?

Accepted Answer

A mosquito transmitting malaria after the parasite multiplies inside it

Question 14

Which of the following best describes the prodromal period in the course of an infectious disease?

Accepted Answer

Short period after incubation with early, mild, nonspecific symptoms

Question 15

Which of the following is a correct formula for calculating the mortality rate of a disease?

Accepted Answer

$$	ext{Mortality Rate} = \frac{	ext{Number of deaths from a disease}}{	ext{Total population in a given period}}$$

Question 16

Which of the following is a reason why emerging infectious diseases are increasing in incidence?

Accepted Answer

Genetic recombination and evolution of microbes

Question 17

Which of the following is an example of a focal infection?

Accepted Answer

Bacterial endocarditis that began as a local oral infection

Question 18

Which of the following best describes the role of the Centers for Disease Control and Prevention (CDC)?

Accepted Answer

Collecting and analyzing epidemiological information in the United States

Question 19

Which of the following is a characteristic of a chronic disease?

Accepted Answer

Symptoms develop slowly and last for a long period

Question 20

Which of the following is an example of descriptive epidemiology?

Accepted Answer

Collecting and mapping data on the occurrence of cholera in London

Chapter 14

Study Guide - Practice Questions