$$Prevalence = \frac{\text{Number of existing cases}}{\text{Total population}}$$

Question 1

Which of the following best describes a reservoir in epidemiology?

Accepted Answer

The primary habitat of a pathogen in the natural world, which can be living or nonliving

Question 2

A nurse who unknowingly carries and spreads MRSA to patients without showing symptoms is best classified as which type of carrier?

Accepted Answer

Passive carrier

Question 3

Which of the following is an example of a zoonosis?

Accepted Answer

Rabies transmitted from a dog to a human

Question 4

Which pattern of transmission involves an inanimate object that harbors and transmits pathogens?

Accepted Answer

Fomite

Question 5

A propagated epidemic is characterized by which of the following?

Accepted Answer

A sustained increase in cases over time due to person-to-person transmission

Question 6

Which equation correctly represents prevalence in epidemiology?

Accepted Answer

$$Prevalence = \frac{	ext{Number of existing cases}}{	ext{Total population}}$$

Question 7

Why is it difficult to eradicate zoonotic diseases?

Accepted Answer

Because the animal reservoir must also be eradicated to eliminate the disease

Question 8

Which of the following is a major concern with nosocomial infections?

Accepted Answer

They are acquired or developed during a hospital stay and may involve drug-resistant microorganisms

Question 9

Which of the following best describes herd immunity?

Accepted Answer

Resistance of a group to infection due to a high proportion of immune members, protecting non-immunized individuals

Question 10

Which of the following is true regarding the virulence of host-to-host pathogens over time?

Accepted Answer

Virulence tends to diminish and host resistance increases due to coevolution

Question 11

A patient develops a boil (furuncle) after a minor skin injury. Which organism is most likely responsible?

Accepted Answer

Staphylococcus aureus

Question 12

Which of the following is a correct statement about MRSA?

Accepted Answer

MRSA carries multiple drug resistances and some strains are resistant to all major drug groups except vancomycin

Question 13

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

Accepted Answer

Using a contaminated doorknob (fomite)

Question 14

Which of the following best describes the role of the CDC in epidemiology?

Accepted Answer

The CDC collects, analyzes, and reports data on infectious diseases and shares statistics with the WHO

Question 15

Which of the following equations correctly represents incidence?

Accepted Answer

$$Incidence = \frac{	ext{Number of new cases}}{	ext{Total population}}$$

Question 16

A foodborne outbreak of gastrointestinal distress is traced to heat-stable enterotoxins. Which disease is most likely involved?

Accepted Answer

Staphylococcal food intoxication

Question 17

Which of the following is a universal precaution to prevent nosocomial infections?

Accepted Answer

Using gloves and proper hand hygiene when handling blood and body fluids

Question 18

Which of the following best describes a chronic carrier?

Accepted Answer

An individual who shelters the infectious agent for a long period

Question 19

Which of the following is a correct statement about the relationship between immunized and non-immunized individuals in herd immunity?

Accepted Answer

Immunized individuals protect non-immunized individuals by breaking the cycle of infectivity

Question 20

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

Accepted Answer

$$Mortality\ Rate = \frac{	ext{Number of deaths due to a disease}}{	ext{Total population}}$$

Microbe-Human Interactions: Epidemiology, Transmission, and Reservoirs

Study Guide - Practice Questions