Chapter 14 Flashcards

1) A commensal bacterium
A) does not receive any benefit from its host.
B) is beneficial to its host.
C) may also be an opportunistic pathogen.
D) isn't capable of causing disease in its host.
E) always causes disease in its host.

2) Which of the following statements is TRUE?
A) Both members are harmed in a symbiotic relationship.
B) Members of a symbiotic relationship cannot live without each other.
C) A parasite is not in symbiosis with its host.
D) Symbiosis always refers to different organisms living together and benefiting from each
other.
E) At least one member must benefit in a symbiotic relationship.

3) A healthcare-associated infection (traditionally known as a nosocomial infection) is
A) always present, but is inapparent at the time of hospitalization.
B) acquired during the course of hospitalization.
C) always caused by medical personnel.
D) only a result of surgery.
E) always caused by pathogenic bacteria.

4) The major significance of Robert Koch's work is that
A) microorganisms are present in a diseased animal.
B) diseases can be transmitted from one animal to another.
C) microorganisms can be cultured.
D) microorganisms cause disease.
E) microorganisms are the result of disease.

5) Which of the following is NOT a verified exception in the use of Koch's postulates?
A) Some diseases have poorly defined etiologies.
B) Some pathogens can cause several disease conditions.
C) Some human diseases have no other known animal host.
D) Some diseases are not caused by microbes.
E) Some diseases are noncommunicable.

6) Which of the following diseases is NOT spread by droplet infection?
A) botulism
B) tuberculosis
C) measles
D) the common cold
E) diphtheria

7) Biological transmission differs from mechanical transmission in that biological transmission
A) occurs when a pathogen is carried on the feet of an insect.
B) involves fomites.
C) involves reproduction of a pathogen in an arthropod vector prior to transmission.
D) requires direct contact.
E) works only with noncommunicable diseases.

8) Which of the following definitions is INCORRECT?
A) endemic: a disease that is constantly present in a population
B) epidemic: a disease that is constantly present across the world
C) pandemic: a disease that affects a large number of people in the world in a short time
D) sporadic: a disease that affects a population occasionally
E) incidence: number of new cases of a disease

9) Focal infections initially start out as
A) sepsis.
B) bacteremia.
C) local infections.
D) septicemia.
E) systemic infections.

10) The rise in herd immunity amongst a population can be directly attributed to
A) increased use of antibiotics.
B) improved handwashing.
C) vaccinations.
D) antibiotic-resistant microorganisms.
E) None of the answers is correct

11) Koch observed Bacillus anthracis multiplying in the blood of cattle. What is the condition
specifically called when bacteria are multiplying in the blood?
A) bacteremia
B) focal infection
C) local infection
D) septicemia
E) systemic infection

12) Which one of the following does NOT contribute to the incidence of healthcare-associated
infections?
A) antibiotic resistance
B) lapse in aseptic techniques
C) gram-negative cell walls
D) lack of handwashing
E) lack of disinfecting surfaces

13) Transient microbiota differ from normal microbiota in that transient microbiota
A) cause diseases.
B) are found in a certain location on the host.
C) are always acquired by direct contact.
D) are present for a relatively short time.
E) never cause disease.

14) Which of the following statements about healthcare-associated infections is FALSE?
A) They occur in compromised patients.
B) They may be caused by opportunists.
C) They may be caused by drug-resistant bacteria.
D) They may be caused by normal microbiota.
E) The patient was infected before hospitalization.

15) One effect of washing regularly with antibacterial agents is the removal of normal
microbiota. This can result in
A) body odor.
B) fewer diseases.
C) increased susceptibility to disease.
D) normal microbiota returning immediately.
E) no bacterial growth because washing removes their food source.

16) Which of the following is NOT a reservoir of infection?
A) a sick person
B) a healthy person
C) a sick animal
D) a hospital
E) None of the answers is correct; all of these can be reservoirs of infection.

17) Which of the following is NOT a communicable disease?
A) malaria
B) AIDS
C) tuberculosis
D) tetanus
E) typhoid fever

18) Which of the following is a fomite?
A) water
B) droplets from a sneeze
C) pus
D) insects
E) a hypodermic needle

19) Which of the following statements about biological transmission is FALSE?
A) The pathogen reproduces in the vector.
B) The pathogen may enter the host in the vector's feces.
C) Houseflies are an important vector.
D) The pathogen may be injected by the bite of the vector.
E) The pathogen may require the vector as a host.

20) Which of the following definitions is INCORRECT?
A) acute: a short-lasting primary infection
B) inapparent: infection characteristic of a carrier state
C) chronic: a disease that develops slowly and lasts for months
D) primary infection: an initial illness
E) secondary infection: a long-lasting illness

21) Symptoms of disease differ from signs of disease in that symptoms
A) are changes felt by the patient.
B) are changes observed by the physician.
C) are specific for a particular disease.
D) always occur as part of a syndrome.

22) The science that deals with when diseases occur and how they are transmitted is called
A) ecology.
B) epidemiology.
C) communicable disease.
D) morbidity and mortality.
E) public health.

23) Figure 14.1 shows the incidence of influenza during a typical year in the northern
hemisphere. Which letter on the graph indicates the endemic level?
A) a
B) b
C) c
D) d

24) In Figure 14.1, which letter on the graph indicates the epidemic level?
A) a
B) b
C) c
D) d

25) In Figure 14.1, which letter indicates the gradual end of the epidemic outbreak?
A) a
B) b
C) c
D) d

26) Would you expect the graph to change if this was for the southern hemisphere, rather than
the northern hemisphere? If so, how?
A) No, the graph would not change. Influenza epidemics occur at the same time each year.
B) Yes, because the population in the northern hemisphere is less than that in the southern
hemisphere, the peak of the graph would be higher.
C) Yes, because the weather is hotter in the southern hemisphere than in the northern
hemisphere, you could expect to see less cases overall in the graph, leading to a lower peak.
D) Yes, because the seasons are reversed in the southern hemisphere. While weather doesn't
directly cause influenza outbreaks, the cold, dry air and human crowding indoors contribute to
increased cases. The southern hemisphere would still have a peak, but it would be at a different
time of year than the northern hemisphere

27) Emergence of infectious diseases can be attributed to all of the following EXCEPT
A) antibiotic resistance.
B) climatic changes.
C) new strains of previously known agents.
D) ease of travel.
E) The emergence of infectious diseases can be attributed to all of these.

28) Which of the following pairs is mismatched?
A) malaria – foodborne transmission
B) salmonellosis – vehicle transmission
C) syphilis – direct contact
D) influenza – droplet infection

29) Which of the following can contribute to postoperative infections?
A) using syringes more than once
B) normal microbiota on the operating room staff
C) errors in aseptic technique
D) antibiotic resistance
E) All of the answers are correct

30) In Figure 14.2, when is the prevalence the highest?
A) July
B) January
C) February
D) March

31) In Figure 14.2, which one of the following choices has the highest morbidity rate?
A) July
B) October
C) November
D) December

32) A cold transmitted by a facial tissue is an example of
A) direct contact.
B) droplet transmission.
C) fomite.
D) vector.
E) vehicle transmission

33) A researcher has performed a prospective study on a disease. To which specific kind of
epidemiological study is this referring?
A) analytical
B) case control
C) descriptive
D) experimental
E) prodromal

34) The CDC is located in
A) Atlanta, GA.
B) Washington, DC.
C) New York City, NY.
D) Los Angeles, CA.
E) Chicago, IL.

35) A disease in which the causative agent remains inactive for a time before producing
symptoms is referred to as
A) subacute.
B) subclinical.
C) latent.
D) zoonotic.
E) acute.

36) A needlestick is an example of
A) direct contact.
B) droplet transmission.
C) indirect contact transmission by fomite.
D) direct biological transmission by vector.
E) vehicle transmission.

37) Which of the following is NOT a predisposing factor of disease?
A) lifestyle
B) genetic background
C) climate
D) occupation
E) All of these are predisposing factors of disease.

38) In which of the following diseases can gender be considered a viable predisposing factor?
A) urinary tract infections
B) pneumonia
C) salmonellosis
D) tetanus
E) anthrax

39) In which of the following patterns of disease does the patient experience no signs or
symptoms?
A) prodromal
B) decline
C) convalescence
D) incubation
E) both incubation and convalescence

Situation 14.1
During a six-month period, 239 cases of pneumonia occurred in a town of 300 people. A clinical
case was defined as fever ≥ 39°C lasting >2 days with three or more symptoms (i.e., chills,
sweats, severe headache, cough, aching muscles/joints, fatigue, or feeling ill). A laboratoryconfirmed
case was defined as a positive result for antibodies against Coxiella burnetii. Before
the outbreak, 2000 sheep were kept northwest of the town. Of the 20 sheep tested from the flock,
15 were positive for C. burnetii antibodies. Wind blew from the northwest, and rainfall was 0.5
cm compared with 7 to 10 cm during each of the previous three years.
40) Situation 14.1 is an example of
A) human reservoirs.
B) a zoonosis.
C) a nonliving reservoir.
D) a vector.
E) a focal infection.

Situation 14.1
During a six-month period, 239 cases of pneumonia occurred in a town of 300 people. A clinical
case was defined as fever ≥ 39°C lasting >2 days with three or more symptoms (i.e., chills,
sweats, severe headache, cough, aching muscles/joints, fatigue, or feeling ill). A laboratoryconfirmed
case was defined as a positive result for antibodies against Coxiella burnetii. Before
the outbreak, 2000 sheep were kept northwest of the town. Of the 20 sheep tested from the flock,
15 were positive for C. burnetii antibodies. Wind blew from the northwest, and rainfall was 0.5
cm compared with 7 to 10 cm during each of the previous three years.

41) The etiologic agent of the disease in Situation 14.1 is
A) sheep.
B) soil.
C) Coxiella burnetii.
D) pneumonia.
E) wind.

42) The method of transmission of the disease in Situation 14.1 was
A) direct contact.
B) droplet.
C) indirect contact.
D) vector-borne.
E) vehicle.

43) Which of the following is NOT an example of microbial antagonism?
A) acid production by bacteria
B) bacteriocin production
C) bacteria occupying host receptors
D) bacteria causing disease
E) bacteria producing vitamin K

44) The yeast Candida albicans does NOT normally cause disease because of
A) symbiotic bacteria.
B) antagonistic bacteria.
C) parasitic bacteria.
D) commensal bacteria.
E) other fungi.

45) If a prodromal period exists for a certain disease, it should occur prior to
A) incubation.
B) illness.
C) decline.
D) convalescence.

46) Which one of the following is NOT a zoonosis?
A) cat-scratch disease
B) Hantavirus pulmonary syndrome
C) rabies
D) tapeworm
E) All of these are zoonoses.

47) Pseudomonas bacteria colonized the bile duct of a patient following his liver transplant
surgery. This is an example of a
A) communicable disease.
B) latent infection.
C) nosocomial infection.
D) sporadic disease.
E) None of the answers is correct.

48) The graph in Figure 14.3 shows the incidence of polio in the United States. The period
between 1945 and 1955 indicates a(n)
A) endemic level.
B) epidemic level.
C) sporadic infection.
D) communicable disease.
E) pandemic.

49) Interpreting this graph, can we conclude that polio has been eradicated globally? Why or
why not?
A) Yes, as the number of reported cases goes to zero around 1965.
B) No, because polio is part of the normal microbiota, and could become resurgent if vaccination
efforts lapse.
C) No, because the graph only depicts incidence of polio in the United States.
D) Yes, because a zero incidence rate for over 40 years clearly indicates there are no longer any
susceptibles left in the global population.

50) Which of the following statements is FALSE?
A) Antimicrobial therapy for hemodialysis-associated infections increases antibiotic resistance.
B) S. aureus is differentiated from other mannitol+ cocci by the coagulase test.
C) The M in MRSA stands for mannitol.
D) The USA100 strain accounts for most hospital-acquired MRSA.
E) The USA300 strain accounts for most community-acquired MRSA