Q: What is the formula for calculating incidence rate in epidemiology?

$$\frac{\text{Number of new cases}}{\text{Total population at risk during a specific time period}}$$

Question 1

Which of the following best describes the primary goal of epidemiology?

Accepted Answer

To identify and prevent factors that cause disease in populations

Question 2

A hospital reports a sudden increase in admissions for severe respiratory symptoms, but all common respiratory pathogens test negative. Which epidemiological question should be asked FIRST?

Accepted Answer

Where and when did the cases occur?

Question 3

Which of the following is an example of a propagated epidemic?

Accepted Answer

Influenza spreading from person to person over several weeks

Question 4

What is the formula for calculating incidence rate in epidemiology?

Accepted Answer

$$\frac{	ext{Number of new cases}}{	ext{Total population at risk during a specific time period}}$$

Question 5

A screening test for a disease is said to have high specificity. What does this mean?

Accepted Answer

It rarely gives false positives

Question 6

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

Accepted Answer

A significant portion of the population is immune, indirectly protecting those who are not immune

Question 7

Which of the following is NOT a criterion from the Bradford Hill criteria for causation?

Accepted Answer

Randomization

Question 8

A new disease appears in multiple continents at the same time. What is this scenario called?

Accepted Answer

Pandemic

Question 9

Which of the following is a correct definition of the basic reproduction rate ($$R_0$$)?

Accepted Answer

The average number of secondary cases produced by one infected individual in a fully susceptible population

Question 10

Which of the following is a healthcare-associated infection (HAI)?

Accepted Answer

A urinary tract infection acquired from a catheter during a hospital stay

Question 11

A researcher wants to determine if a new vaccine reduces the incidence of a disease. Which study design is most appropriate?

Accepted Answer

Randomized control trial

Question 12

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

Accepted Answer

Chlamydia

Question 13

What is the main difference between a screening test and a diagnostic test?

Accepted Answer

Screening tests are less accurate and used on healthy populations, while diagnostic tests are more accurate and used for confirmation

Question 14

Which of the following best describes a sporadic disease?

Accepted Answer

A disease that occurs occasionally and at irregular intervals

Question 15

A case-control study is best used to:

Accepted Answer

Compare people with a disease to those without it to identify past exposures

Question 16

Which of the following is a correct formula for case fatality rate (CFR)?

Accepted Answer

$$\frac{	ext{Number of deaths due to a disease}}{	ext{Number of persons infected with the disease}} 	imes 100\%$$

Question 17

Which of the following is a real-world example of a common-source epidemic?

Accepted Answer

A group of people developing hepatitis A after eating contaminated food at a picnic

Question 18

Which of the following is a key function of the CDC in the United States?

Accepted Answer

Collecting, analyzing, and reporting data on notifiable diseases

Question 19

Which of the following is an example of a re-emerging infectious disease?

Accepted Answer

Tuberculosis becoming more prevalent due to drug resistance

Question 20

Which of the following best describes the role of an infection-control officer in a hospital?

Accepted Answer

Implementing and monitoring aseptic practices to prevent healthcare-associated infections

Epidemiology of Infectious Diseases – Microbiology: A Systems Approach (Chapter 14 Study Notes)

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