CBIC Outbreak Investigation 2

Question 1

During an outbreak investigation, which epidemiological measure best describes the proportion of exposed persons who develop the disease?

Accepted Answer

Attack rate

Answer

The attack rate is the proportion of exposed individuals who develop illness during a specific outbreak period.

Question 2

A cluster of surgical site infections is identified in a hospital. What is the FIRST step in a formal outbreak investigation?

Accepted Answer

Verify the diagnosis and confirm the outbreak exists

Answer

Verifying the diagnosis and confirming a true outbreak (vs. pseudooutbreak or surveillance artifact) is always the first step.

Question 3

Which type of epidemic curve shape is most consistent with a common-source, point-source outbreak?

Accepted Answer

Sharp rise with a rapid fall within one incubation period

Answer

A point-source outbreak produces a sharp, narrow epidemic curve because all exposures occur at essentially the same time.

Question 4

An infection preventionist notes that Clostridioides difficile rates on a unit have tripled. Before declaring an outbreak, which action should be taken FIRST?

Accepted Answer

Review changes in testing methods or case definitions

Answer

Changes in testing platforms or case definitions can create pseudooutbreaks; these must be ruled out before an investigation begins.

Question 5

In outbreak investigation, a case-control study is most useful when:

Accepted Answer

The number of cases is small and the source is unknown

Answer

Case-control studies are efficient when cases are few, allowing comparison of exposures between cases and matched controls to identify the source.

CBIC - Certification Board of Infection Control Practice Test

CBIC - Certification Board of Infection Control Practice Test

CBIC Outbreak Investigation 2