Question 1

Which of the following best describes the relationship between normal microbiota and the host in the human body?

Accepted Answer

Commensalism, where one organism benefits and the other is unaffected

Question 2

A patient develops a yeast infection (vaginitis) after taking antibiotics for a bacterial infection. Which mechanism of the normal microbiota was disrupted, allowing Candida albicans to overgrow?

Accepted Answer

Maintenance of pH by normal microbiota

Question 3

Which of the following is NOT a step in Koch’s postulates for determining the etiology of a disease?

Accepted Answer

The pathogen must be able to infect only humans

Question 4

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

Accepted Answer

Endemic

Question 5

Calculate the incidence rate per 100,000 people for HIV in Ohio in 2023, given 861 new diagnoses and a population of 11.82 million. Use the formula $$	ext{Incidence Rate} = \frac{	ext{Number of new cases}}{	ext{Population}} 	imes 100,000.$$

Accepted Answer

$$\approx 7.3$$

Question 6

Which of the following best explains why the case fatality ratio (CFR) for a disease like COVID-19 might decrease over time?

Accepted Answer

Improved medical treatments and earlier diagnosis

Question 7

A patient is diagnosed with pneumonia after recovering from influenza. This is an example of:

Accepted Answer

A secondary infection

Question 8

Which of the following is a real-world example of a zoonosis?

Accepted Answer

Rabies transmitted from a dog bite

Question 9

A hospital patient develops a urinary tract infection after catheterization. This infection is best classified as:

Accepted Answer

A healthcare-associated infection (HAI)

Question 10

Which of the following is a key reason why hand hygiene is emphasized as a standard precaution in healthcare settings?

Accepted Answer

It reduces the chain of transmission of microbes between patients and staff

Question 11

A disease with an $$R_0 ($$basic reproduction number) less than 1 will:

Accepted Answer

Gradually die out

Question 12

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

Accepted Answer

A person contracts influenza by touching a contaminated doorknob

Question 13

Which of the following best describes the difference between incidence and prevalence?

Accepted Answer

Incidence measures new cases over a period; prevalence measures all cases at a specific time

Question 14

A patient is exposed to a pathogen but does not show symptoms for several days. This period is known as:

Accepted Answer

Incubation period

Question 15

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

Accepted Answer

Immunosuppression

Question 16

A patient with sepsis is found to have bacteria actively multiplying in the blood. This condition is best described as:

Accepted Answer

Septicemia

Question 17

Which of the following is an example of vehicle transmission?

Accepted Answer

A person contracts cholera from contaminated water

Question 18

Which of the following best explains why some pathogens cannot be studied using Koch’s postulates?

Accepted Answer

They cannot be cultured in artificial media

Question 19

A patient is diagnosed with a latent infection. Which of the following is the best example of this type of disease?

Accepted Answer

Herpes simplex virus causing intermittent cold sores

Question 20

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

Accepted Answer

Widespread use of antibiotics and pesticides

Principles of Disease and Epidemiology: Study Notes for Microbiology Students

Study Guide - Practice Questions

Study Guide - Flashcards