Epidemiology and Disease Prevention
Comprehensive Examination 2026
This examination assesses core competencies across epidemiological principles,
outbreak investigation protocols, biostatistical measures, and disease prevention
strategies.
Question 1
Public health officials observe a sudden spike in new cases of viral gastroenteritis among
residents of a long-term care facility over a 48-hour period. What epidemiological
measure is most appropriate to calculate for this specific bounded population during this
short window?
● A) Period prevalence
● B) Point prevalence
● C) Attack rate
● D) Person-years incidence
Correct Answer: C
Explanation: The attack rate is a specialized form of cumulative incidence used
specifically for acute outbreaks over a short, defined observation window in a closed
population. Point prevalence would incorrectly measure existing rather than new cases,
failing to reflect the speed of viral spread.
Question 2
A county health department initiates a mammography screening initiative to identify
asymptomatic breast cancer in high-risk women aged 40 to 65. Under which category of
disease prevention does this intervention fall?
● A) Secondary prevention
● B) Primary prevention
● C) Tertiary prevention
, ● D) Primordial prevention
Correct Answer: A
Explanation: Secondary prevention focuses on early detection and intervention before
symptoms manifest to stop or slow disease progression. Primary prevention differs
because it aims to prevent disease occurrence entirely by eliminating exposure or risk
factors before pathology begins.
Question 3
An epidemiologist plots an epidemic curve for a norovirus outbreak at a university
campus and notices a sharp, steep peak followed by a rapid, symmetrical decline within a
single incubation period. What mode of transmission does this pattern signify?
● A) Propagated spread
● B) Continuous common source
● C) Intermittent common source
● D) Point source
Correct Answer: D
Explanation: A point source epidemic occurs when a population is exposed to a single
common harmful agent over a brief period, producing a distinct, sharp single peak within
one incubation period. A continuous common source exposure lasts longer, resulting in a
plateaued curve rather than a swift, symmetrical decline.
Question 4
In a cohort study investigating occupational solvent exposure and peripheral neuropathy,
researchers calculate an epidemiological ratio. If the baseline risk in the exposed group is
0.12 and in the unexposed group is 0.03, what is the Relative Risk (RR)?
● A) 0.25
● B) 4.00
● C) 0.09
● D) 3.00
,Correct Answer: B
Explanation: Relative Risk is calculated by dividing the incidence in the exposed group
(0.12) by the incidence in the unexposed group (0.03), yielding 4.00. Option D represents
the Risk Difference (0.12 minus 0.03 = 0.09) or an incorrect subtraction ratio rather than a
true risk ratio.
Question 5
A state laboratory tests a new rapid diagnostic strip for Influenza A. Out of 100 individuals
verified to have the virus via gold-standard PCR, 88 test positive on the rapid strip. What
does the value 88% represent?
● A) Specificity
● B) Sensitivity
● C) Positive Predictive Value
● D) Negative Predictive Value
Correct Answer: B
Explanation: Sensitivity measures the proportion of actual diseased individuals who
correctly test positive (true positives divided by all with disease). Specificity measures
the proportion of healthy individuals correctly identified as disease-free, which cannot be
determined without testing non-infected controls.
Question 6
During a measles outbreak investigation, public health officers order asymptomatic
individuals who were exposed to an index case on an international flight to remain at
home for 21 days. What intervention is being executed?
● A) Isolation
● B) Reverse isolation
● C) Universal precaution
● D) Quarantine
Correct Answer: D
Explanation: Quarantine restricts the movement of well, asymptomatic individuals who
have been exposed to a contagious agent to see if they become ill. Isolation differs by
, specifically separating symptomatic, infected individuals from the healthy population to
prevent transmission.
Question 7
In a rural municipality, a hospital system logs every confirmed case of hepatitis C directly
into a centralized state registry without prompting. What form of public health monitoring
is being utilized?
● A) Passive surveillance
● B) Active surveillance
● C) Sentinel surveillance
● D) Syndromic surveillance
Correct Answer: A
Explanation: Passive surveillance relies on mandatory or voluntary reporting of health
data by healthcare providers without proactive data collection by health agencies. Active
surveillance would involve health department officials actively contacting clinics and
reviewing medical records to find cases.
Question 8
In an epidemiological model of Lyme disease, Ixodes scapularis (the blacklegged tick)
carries Borrelia burgdorferi from white-footed mice to human hosts. In the classic
Epidemiological Triad, how is the tick classified?
● A) Host
● B) Agent
● C) Vector
● D) Environment
Correct Answer: C
Explanation: A vector is an living organism (like a tick) that transports an infectious agent
from a reservoir or host to a susceptible human host. The bacteria (Borrelia burgdorferi)
is the agent, not the tick itself.
Comprehensive Examination 2026
This examination assesses core competencies across epidemiological principles,
outbreak investigation protocols, biostatistical measures, and disease prevention
strategies.
Question 1
Public health officials observe a sudden spike in new cases of viral gastroenteritis among
residents of a long-term care facility over a 48-hour period. What epidemiological
measure is most appropriate to calculate for this specific bounded population during this
short window?
● A) Period prevalence
● B) Point prevalence
● C) Attack rate
● D) Person-years incidence
Correct Answer: C
Explanation: The attack rate is a specialized form of cumulative incidence used
specifically for acute outbreaks over a short, defined observation window in a closed
population. Point prevalence would incorrectly measure existing rather than new cases,
failing to reflect the speed of viral spread.
Question 2
A county health department initiates a mammography screening initiative to identify
asymptomatic breast cancer in high-risk women aged 40 to 65. Under which category of
disease prevention does this intervention fall?
● A) Secondary prevention
● B) Primary prevention
● C) Tertiary prevention
, ● D) Primordial prevention
Correct Answer: A
Explanation: Secondary prevention focuses on early detection and intervention before
symptoms manifest to stop or slow disease progression. Primary prevention differs
because it aims to prevent disease occurrence entirely by eliminating exposure or risk
factors before pathology begins.
Question 3
An epidemiologist plots an epidemic curve for a norovirus outbreak at a university
campus and notices a sharp, steep peak followed by a rapid, symmetrical decline within a
single incubation period. What mode of transmission does this pattern signify?
● A) Propagated spread
● B) Continuous common source
● C) Intermittent common source
● D) Point source
Correct Answer: D
Explanation: A point source epidemic occurs when a population is exposed to a single
common harmful agent over a brief period, producing a distinct, sharp single peak within
one incubation period. A continuous common source exposure lasts longer, resulting in a
plateaued curve rather than a swift, symmetrical decline.
Question 4
In a cohort study investigating occupational solvent exposure and peripheral neuropathy,
researchers calculate an epidemiological ratio. If the baseline risk in the exposed group is
0.12 and in the unexposed group is 0.03, what is the Relative Risk (RR)?
● A) 0.25
● B) 4.00
● C) 0.09
● D) 3.00
,Correct Answer: B
Explanation: Relative Risk is calculated by dividing the incidence in the exposed group
(0.12) by the incidence in the unexposed group (0.03), yielding 4.00. Option D represents
the Risk Difference (0.12 minus 0.03 = 0.09) or an incorrect subtraction ratio rather than a
true risk ratio.
Question 5
A state laboratory tests a new rapid diagnostic strip for Influenza A. Out of 100 individuals
verified to have the virus via gold-standard PCR, 88 test positive on the rapid strip. What
does the value 88% represent?
● A) Specificity
● B) Sensitivity
● C) Positive Predictive Value
● D) Negative Predictive Value
Correct Answer: B
Explanation: Sensitivity measures the proportion of actual diseased individuals who
correctly test positive (true positives divided by all with disease). Specificity measures
the proportion of healthy individuals correctly identified as disease-free, which cannot be
determined without testing non-infected controls.
Question 6
During a measles outbreak investigation, public health officers order asymptomatic
individuals who were exposed to an index case on an international flight to remain at
home for 21 days. What intervention is being executed?
● A) Isolation
● B) Reverse isolation
● C) Universal precaution
● D) Quarantine
Correct Answer: D
Explanation: Quarantine restricts the movement of well, asymptomatic individuals who
have been exposed to a contagious agent to see if they become ill. Isolation differs by
, specifically separating symptomatic, infected individuals from the healthy population to
prevent transmission.
Question 7
In a rural municipality, a hospital system logs every confirmed case of hepatitis C directly
into a centralized state registry without prompting. What form of public health monitoring
is being utilized?
● A) Passive surveillance
● B) Active surveillance
● C) Sentinel surveillance
● D) Syndromic surveillance
Correct Answer: A
Explanation: Passive surveillance relies on mandatory or voluntary reporting of health
data by healthcare providers without proactive data collection by health agencies. Active
surveillance would involve health department officials actively contacting clinics and
reviewing medical records to find cases.
Question 8
In an epidemiological model of Lyme disease, Ixodes scapularis (the blacklegged tick)
carries Borrelia burgdorferi from white-footed mice to human hosts. In the classic
Epidemiological Triad, how is the tick classified?
● A) Host
● B) Agent
● C) Vector
● D) Environment
Correct Answer: C
Explanation: A vector is an living organism (like a tick) that transports an infectious agent
from a reservoir or host to a susceptible human host. The bacteria (Borrelia burgdorferi)
is the agent, not the tick itself.
