Chapter Three Questions 2010
1. An outbreak of disease should be reported to the local or state health department:
a. If the diagnosis is uncertain
b. If the disease is infectious
c. If the disease is serious
d. If the outbreak involves at least 10 people
e. Under all circumstances
2. Arizona, Colorado, and New Mexico report cases of an unexplained respiratory tract illness
with a high case fatality ratio. Which of the following is most reliably true regarding this event?
a. It is an epidemic
b. It is an example of active surveillance
c. It is appropriately investigated by the CDC
d. It is attributable to improve surveillance
e. It is not an outbreak because the condition may be endemic
3. Cases of “flesh-eating” group A streptococcal disease are reported in a defined population.
Which of the following types of information would be most helpful for determining whether
these cases represent a disease outbreak?
a. The clinical features and methods of diagnosing the disease.
b. The disease vector and reservoir
c. The exact location and timing of disease onset
d. The incubation period and pattern of disease transmission
e. The usual disease patterns and reporting practices.
4. An official from the state department of public health visits outpatient clinics and
emergency departments to determine the number of cases of postexposure prophylaxis
for rabies. The official’s action is an example of:
a. Active surveillance
b. Case finding
c. Outbreak investigation
d. Screening
e. Secondary prevention
5. An article highlighting the long-term consequences of inadequately treated Lyme disease is
published in a medical journal. After a summary of the article appears in popular
newspapers and magazines, patients with joint pains begin insisting that their physicians
test them for Lyme disease. Cases in which the test results are positive are reported as
cases of Lyme borreliosis. This represents:
a. A change in reporting that would underestimate prevalence
b. A change in surveillance that would have an unknown effect
c. A change in surveillance that would overestimate the likelihood of an outbreak
d. Active surveillance
e. Recall bias.
1 Julie A. Fox
Chapter Three Questions 2010
A Democratic president invites a dozen or so of his dearest friends, prominent Republican
legislators, to a formal luncheon at the White House. The salmon mousse is even more popular
than highlights from the campaign finance reform movement. Within 24 hours, 11 of the 17
diners experience abdominal pain, vomiting, and diarrhea. The president, who happens not to
like salmon because it deadens the taste buds to the subtleties of beef jerky, feels fine. In fact, he
goes jogging. Of the 11 symptomatic guests, 4 have fever and 7 do not; 5 have an elevated
white blood cell count, and 6 do not; 6 ate shrimp bisque, and 5 did not; 9 ate salmon mousse,
and 2 did not; and 1 goes on to have surgery for acute cholecystitis resulting from an impacted
calculus (stone) in the common bile duct. Of the 11 symptomatic guests, 10 recover within 3 days;
the exception is the senator who underwent surgery and recovered over a longer period. The guests
at this luncheon had shared no other meals at any time recently.
6. The phenomenon described:
a. Is a coincidence until proven otherwise
b. Is a disease outbreak
c. Is attributable to bacterial infection
d. Is not an outbreak because the usual pattern of disease is unknown
e. Should be investigated by the CDC
7. The attack rate is:
a. 4/11
b. 5/11
c. 11/13
d. 1/17
e. 11/17 (# ill/ [# ill + # well]= 11/17)
8. An early priority in investigating the phenomenon would be to:
a. Close the kitchen temporarily
b. Define a case
c. Perform a case-control study
d. Perform stool tests
e. Submit food samples to the laboratory
9. The best-case definition for the guests’ disease would be:
a. Abdominal pain, vomiting, and diarrhea within 24 hours of the state luncheon
b. Acute viral gastroenteritis
c. Staphylococcal food poisoning
d. The onset of abdominal pain and fever after the state luncheon
e. Vomiting, diarrhea and an elevated white blood cell count
2 Julie A. Fox
Chapter Three Questions 2010
10. Suspecting that the disease is the result of a common source exposure involving
contaminated food, the investigators attempt to determine which food is responsible.
Their initial task is to:
a. Analyze food specimens in the laboratory
b. Close the White House kitchen
c. Examine the food preparers
d. Interview the symptomatic guests to find out what they ate
e. Perform a case-control study.
11. The investigators are unable to identify a single food that was eaten by every
symptomatic guest. They should:
a. Abandon the investigation because the disease is not serious
b. Conclude that the disease was not food-borne
c. Conclude the investigation but without identifying the source
d. Implicate the food least eaten by those without symptoms
e. Implicate the food most eaten by those with symptoms.
12. The investigators suspect that the salmon mousse is the source of the disease. To
confirm or refute their suspicion, they should:
a. Conduct a prospective study
b. Identify the causative agent
c. Initiate active surveillance
d. Perform a case-study in which the cases are the guests who ate salmon mousse and
the controls are those who did not.
e. Perform a case-control study in which the cases are the guests who became ill
and the controls are those who did not.
3 Julie A. Fox