CBIC Outbreak Investigation 3

Question 1

During a foodborne outbreak investigation at a hospital cafeteria, which analytical study design calculates a relative risk directly?

Accepted Answer

Cohort study

Answer

A cohort study follows exposed and unexposed groups forward, allowing direct calculation of incidence rates and relative risk.

Question 2

A hospital is investigating an MRSA outbreak on an ICU. Whole-genome sequencing of isolates is used to:

Accepted Answer

Assess clonality and transmission chains among cases

Answer

Whole-genome sequencing identifies genetic relatedness of isolates, helping trace transmission chains and confirm clonal outbreaks.

Question 3

Which measure should an IP use to compare infection rates between units with different patient populations?

Accepted Answer

Risk-adjusted or stratified infection rates

Answer

Risk adjustment or stratification accounts for differences in patient acuity and exposure time, enabling valid comparisons across units.

Question 4

An outbreak of gram-negative bacteremia is linked to contaminated IV fluids. Which investigation step confirms the vehicle?

Accepted Answer

Matching the molecular type of patient isolates to product cultures

Answer

Demonstrating identical molecular fingerprints between patient isolates and the suspected contaminated product confirms the transmission vehicle.

Question 5

In a healthcare-associated outbreak, 'generation time' refers to:

Accepted Answer

The average time between successive cases in a transmission chain

Answer

Generation time is the interval between the infection of a primary case and the infection of secondary cases, helping characterize person-to-person spread.

CBIC - Certification Board of Infection Control Practice Test

CBIC - Certification Board of Infection Control Practice Test

CBIC Outbreak Investigation 3