Q: Which of the following equations correctly represents the calculation of disease incidence?

$$\text{Incidence} = \frac{\text{Number of new cases during a specific period}}{\text{Population at risk during that period}}$$

Q: Which of the following best defines morbidity rate?

$$\text{Morbidity rate} = \frac{\text{Number of people affected by a disease}}{\text{Total population at risk}}$$

Question 1

Which of the following best describes the difference between normal microbiota and transient microbiota?

Accepted Answer

Normal microbiota permanently colonize the host, whereas transient microbiota are present for only a short period.

Question 2

A patient develops pneumonia after being hospitalized for a surgical procedure. Which term best describes this infection?

Accepted Answer

Nosocomial infection

Question 3

Which of the following is an example of mutualism?

Accepted Answer

Escherichia coli in the human colon synthesizing vitamin K for the host while obtaining nutrients

Question 4

Which of the following is NOT one of Koch’s postulates?

Accepted Answer

The microorganism must be able to survive outside the host for at least 24 hours.

Question 5

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

Accepted Answer

Endemic

Question 6

Which of the following equations correctly represents the calculation of disease incidence?

Accepted Answer

$$	ext{Incidence} = \frac{	ext{Number of new cases during a specific period}}{	ext{Population at risk during that period}}$$

Question 7

Which of the following best illustrates the concept of herd immunity?

Accepted Answer

A population is protected from an epidemic because a high percentage of individuals are immune, reducing disease spread.

Question 8

Which of the following is a predisposing factor for disease?

Accepted Answer

Age

Question 9

Arrange the following stages of disease in the correct sequence: period of decline, period of convalescence, period of illness, prodromal period, incubation period.

Accepted Answer

Incubation period, prodromal period, period of illness, period of decline, period of convalescence

Question 10

Which of the following is an example of a nonliving reservoir of infection?

Accepted Answer

A contaminated water source

Question 11

Which method of disease transmission is best exemplified by a mosquito transmitting malaria to a human?

Accepted Answer

Biological vector transmission

Question 12

Which of the following best defines a compromised host?

Accepted Answer

A host whose resistance to infection is impaired by disease, therapy, or burns

Question 13

Which of the following is a primary way to prevent nosocomial infections in hospitals?

Accepted Answer

Frequent and proper handwashing by healthcare workers

Question 14

Which of the following is an example of an emerging infectious disease?

Accepted Answer

COVID-19

Question 15

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

Accepted Answer

To monitor, investigate, and control infectious diseases in the United States

Question 16

Which of the following best defines morbidity rate?

Accepted Answer

$$	ext{Morbidity rate} = \frac{	ext{Number of people affected by a disease}}{	ext{Total population at risk}}$$

Question 17

A patient is infected with a pathogen but does not show symptoms and can still transmit the disease. What is this person called?

Accepted Answer

Carrier

Question 18

Which of the following is an example of amensalism?

Accepted Answer

A bacterium producing antibiotics that inhibit the growth of nearby bacteria without being affected itself

Question 19

Which of the following best describes the difference between communicable and non-communicable diseases?

Accepted Answer

Communicable diseases can be transmitted from one host to another, while non-communicable diseases cannot.

Question 20

A hospital patient with a urinary catheter develops a urinary tract infection caused by E. coli, which is part of the normal gut flora. Which best explains this scenario?

Accepted Answer

An opportunistic microorganism caused a nosocomial infection in a compromised host.

Microbiology Study Guide: Infections, Infectious Diseases, and Epidemiology

Study Guide - Practice Questions

Study Guide - Flashcards