Deck 14: Principles of Disease and Epidemiology

Question 1

Which of the following diseases is NOT spread by droplet infection?

A) the common cold
B) measles
C) tuberculosis
D) botulism
E) diphtheria

Answer 1

D

Question 2

Which of the following statements about biological transmission is FALSE?

A) The pathogen may require the vector as a host.
B) The pathogen may be injected by the bite of the vector.
C) The pathogen reproduces in the vector.
D) The pathogen may enter the host in the vector's feces.
E) Houseflies are an important vector.

Answer 2

E

Question 3

Which of the following statements is TRUE?

A) Symbiosis refers to different organisms living together and benefiting from each other.
B) Members of a symbiotic relationship cannot live without each other.
C) At least one member must benefit in a symbiotic relationship.
D) At least one member must not benefit in a symbiotic relationship.
E) A parasite is not in symbiosis with its host.

Answer 3

C

Question 4

Pseudomonas bacteria colonized the bile duct of a patient following his liver transplant surgery. This is an example of a

A) latent infection.
B) communicable disease.
C) nosocomial infection.
D) sporadic disease.
E) None of the answers is correct.

Question 5

If a prodromal period exists for a certain disease, it should occur prior to

A) convalescence.
B) illness.
C) incubation.
D) decline.

Question 6

The major significance of Robert Koch's work is that

A) microorganisms can be cultured.
B) microorganisms are present in a diseased animal.
C) microorganisms are the result of disease.
D) diseases can be transmitted from one animal to another.
E) microorganisms cause disease.

Question 7

The CDC is located in

A) Washington, DC.
B) New York City, NY.
C) Chicago, IL.
D) Las Angeles, CA.
E) Atlanta, GA.

Question 8

Symptoms of disease differ from signs of disease in that symptoms

A) are specific for a particular disease.
B) are changes observed by the physician.
C) are changes felt by the patient.
D) always occur as part of a syndrome.
E) None of the answers is correct.

Question 9

Which of the following is NOT a verified exception in the use of Koch's postulates?

A) Some pathogens can cause several disease conditions.
B) Some human diseases have no other known animal host.
C) Some diseases are not caused by microbes.
D) Some diseases are noncommunicable.
E) Some diseases have poorly defined etiologies.

Question 10

A cold transmitted by a facial tissue is an example of

A) droplet transmission.
B) vehicle transmission.
C) direct contact.
D) vector.
E) fomite.

Question 11

Koch observed Bacillus anthracis multiplying in the blood of cattle. What is this condition called?

A) local infection
B) systemic infection
C) bacteremia
D) septicemia
E) focal infection

Question 12

The yeast Candida albicans does not normally cause disease because of

A) symbiotic bacteria.
B) antagonistic bacteria.
C) other fungi.
D) commensal bacteria.
E) parasitic bacteria.

Question 13

Which of the following is a fomite?

A) a hypodermic needle
B) insects
C) water
D) droplets from a sneeze
E) pus

Question 14

Which of the following is NOT an example of microbial antagonism?

A) bacteria producing vitamin K
B) bacteriocin production
C) bacteria occupying host receptors
D) bacteria causing disease
E) acid production by bacteria

Question 15

A commensal bacterium

A) may also be an opportunistic pathogen.
B) is beneficial to its host.
C) does not receive any benefit from its host.
D) does not infect its host.
E) is beneficial to, and does not infect, its host.

Question 16

A researcher has performed a prospective study on the disease tetanus. To which specific kind of epidemiological study is this referring?

A) case control
B) descriptive
C) prodromal
D) experimental
E) analytical

Question 17

Which of the following can contribute to postoperative infections?

A) using syringes more than once
B) errors in aseptic technique
C) antibiotic resistance
D) normal microbiota on the operating room staff
E) All of the answers are correct.

Question 18

The method of transmission of the disease in Situation 14.1 was

A) droplet.
B) direct contact.
C) vector- borne.
D) indirect contact.
E) vehicle.

Question 19

Which of the following is NOT a communicable diseases?

A) typhoid fever
B) malaria
C) tetanus
D) tuberculosis
E) AIDS

Question 20

Which of the following statements is FALSE?

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

Question 21

Which of the following statements about nosocomial infections is FALSE?

A) They may be caused by normal microbiota.
B) They may be caused by drug- resistant bacteria.
C) They may be caused by opportunists.
D) The patient was infected before hospitalization.
E) They occur in compromised patients.

Question 22

Figure 14.1

Figure 14.1 shows the incidence of influenza during a typical year. Which letter on the graph indicates the endemic level?

A) a
B) b
C) c
D) d
E) The answer cannot be determined based on the information provided.

Question 23

Which one of the following is NOT a zoonosis?

A) tapeworm
B) cat- scratch disease
C) rabies
D) Hantavirus pulmonary syndrome
E) None of the answers is correct; all of these are zoonoses.

Question 24

Which one of the following does NOT contribute to the incidence of nosocomial infections?

A) gram- negative cell walls
B) antibiotic resistance
C) lack of handwashing
D) lapse in aseptic techniques
E) lack of insect control

Question 25

In which of the following patterns of disease does the patient experience no signs or symptoms?

A) decline
B) prodromal
C) convalescence
D) incubation
E) incubation and convalescence

Question 26

Focal infections initially start out as

A) septicemia.
B) systemic infections.
C) bacteremia.
D) sepsis.
E) local infections.

Question 27

Biological transmission differs from mechanical transmission in that biological transmission

A) requires an arthropod.
B) requires direct contact.
C) works only with noncommunicable diseases.
D) involves specific diseases.
E) involves fomites.

Question 28

In which of the following diseases can gender be considered a viable predisposing factor?

A) salmonellosis
B) pneumonia
C) urinary tract infections
D) anthrax
E) tetanus

Question 29

Emergence of infectious diseases can be attributed to all of the following EXCEPT

A) new strains of previously known agents.
B) antibiotic resistance.
C) ease of travel.
D) climatic changes.
E) None of the answers is correct; the emergence of infectious diseases can be attributed to all of these.

Question 30

A needlestick is an example of

A) droplet transmission.
B) vector.
C) fomite.
D) vehicle transmission.
E) direct contact.

Question 31

Which of the following definitions is INCORRECT?

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

Question 32

One effect of washing regularly with antibacterial agents is the removal of normal microbiota. This can result in

A) fewer diseases.
B) no bacterial growth because washing removes their food source.
C) normal microbiota returning immediately.
D) body odor.
E) increased susceptibility to disease.

Question 33

The science that deals with when diseases occur and how they are transmitted is called

A) communicable disease.
B) morbidity and mortality.
C) public health.
D) ecology.
E) epidemiology.

Question 34

Which of the following is NOT a reservoir of infection?

A) a hospital
B) a sick person
C) a healthy person
D) a sick animal
E) None of the answers is correct; all of these can be reservoirs of infection.

Question 35

Figure 14.2

In Figure 14.2, when is the prevalence the highest?

A) February
B) March
C) July
D) January
E) The answer cannot be determined based on the information provided.

Question 36

Transient microbiota differ from normal microbiota in that transient microbiota

A) are always acquired by direct contact.
B) never cause disease.
C) are present for a relatively short time.
D) cause diseases.
E) are found in a certain location on the host.

Question 37

Situation 14.1 is an example of

A) a zoonosis.
B) a focal infection.
C) a nonliving reservoir.
D) a vector.
E) human reservoirs.

Question 38

Which of the following is NOT a predisposing factor of disease?

A) occupation
B) climate
C) genetic background
D) lifestyle
E) None of the answers are correct; all of these are predisposing factors of disease.

Question 39

The rise in herd immunity amongst a population can directly attributed to

A) antibiotic- resistant microorganisms.
B) improved handwashing.
C) vaccinations.
D) increased use of antibiotics.
E) None of the answers is correct.

Question 40

A disease in which the causative agent remains inactive for a time before producing symptoms is referred to as

A) zoonotic.
B) latent.
C) subacute.
D) subclinical.
E) acute.

Question 41

Figure 14.3

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) sporadic infection.
C) pandemic.
D) communicable disease.
E) epidemic level.

Question 42

A nosocomial infection is

A) only a result of surgery.
B) always caused by medical personnel.
C) always present, but is inapparent at the time of hospitalization.
D) always caused by pathogenic bacteria.
E) acquired during the course of hospitalization.

Question 43

Urinary tract infections are the most common forms of nosocomial infections.

Question 44

Figure 14.4

Salmonella Heidelberg gastroenteritis occurred on three cruises aboard the T.S.S. Festivale. Figure 14.4 shows on- board clinic visits for diarrheal illness between February 10 and March 3. Explain the incidence pattern shown on the graph. What are probable modes of transmission? What changes would you recommend before the ship books more cruises after March 3?

Question 45

Both normal and transient flora can become opportunistic pathogens.

Question 46

Compromised hosts are always suffering from suppressed immune systems.

Question 47

Reservoirs of infections are always animate objects.

Question 48

Which of the following definitions is INCORRECT?

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

Question 49

For a particular disease at a specific time period, morbidity rates should always be equal or greater than mortality rates.

Question 50

A researcher only needs to select a cohort group when implementing an analytical epidemiological study.

Question 51

The etiologic agent of the disease in Situation 14.1 is

A) soil.
B) wind.
C) sheep.
D) pneumonia.
E) Coxiella burnetii.

Question 52

When studying the epidemiology of a particular disease, why are retrospective studies commonly undertaken before prospective studies?

Question 53

Dengue fever, a zoonotic disease, is endemic in northern Mexico, but not in the U.S. Provide two plausible explanations for this dichotomy, and explain.

Question 54

MMWR is a publication by the CDC that reports on only emerging diseases.

Question 55

Diseases that are referred to as EIDs have only been discovered in the past fifty years.

Question 56

Which of the following pairs is mismatched?

A) influenza - droplet infection
B) malaria - vector
C) salmonellosis - vehicle transmission
D) syphilis - direct contact
E) None of the pairs is mismatched.

Question 57

A host is not considered diseased until an infection changes one's state of health.

Question 58

Testing the effectiveness of a new drug for anthrax would be best performed as an experimental study.