Deck 18: Introduction to Infectious Diseases

Question 1

Which of these is true of an attenuated strain of a pathogenic microbe infecting a susceptible healthy host?

A)The microbe will NOT replicate in the host.
B)The microbe will replicate in the host but not cause disease.
C)The microbe will replicate in the host and cause disease.
D)The microbe will replicate in the host and ultimately kill the host.
E)The microbe will NOT replicate in the host but will cause disease.

Answer 1

B

Question 2

Ophiostoma novo-ulmi causes disease through:

A)production of chitinase which attacks beetle exoskeletons
B)production of chitinase damaging fungal structures
C)production of endotoxin released from its Gram negative cell wall
D)production of exotoxin released from its Gram positive cell wall
E)production of xylanase,destroying plant conductive tissue

Answer 2

E

Question 3

In the CRISPR-Cas system,which component is responsible for phage destruction?

A)Pre-cRNA transcript
B)cRNA subunits
C)Cas helicase
D)Cas nuclease
E)CRISPR locus

Answer 3

D

Question 4

Examine Table 18.1 in the text.Which symptom or sign would be MOST definitive in diagnosing one of the diseases listed?

A)Muscle aches
B)Fever
C)Decreased CD4+ cell count
D)Muscle pain
E)All are equally diagnostically significant

Question 5

The Herpes simplex I virus is able to avoid detection by the host immune system through this mechanism.

A)Antigenic variation.
B)The production of proteases that destroy antibodies.
C)The establishment of latency in sensory neurons.
D)The production of cytotoxins that kill macrophages.
E)The inhibition of B-cells.

Question 6

In the CRISPR-Cas system,which component is responsible for the bacterial equivalent of "immune memory"?

A)Pre-cRNA transcript
B)cRNA subunits
C)Cas helicase
D)Cas nuclease
E)CRISPR locus

Question 7

In order to cause disease,successful infectious pathogens must be able to do ALL of the following EXCEPT:

A)gain entry to the host.
B)attach to and/or invade host cells.
C)evade host defenses.
D)exit the host.
E)kill the host.

Question 8

In the CRISPR-Cas system,which component is responsible for phage recognition?

A)Pre-cRNA transcript
B)cRNA subunits
C)Cas helicase
D)Cas nuclease
E)CRISPR locus

Question 9

What is studied in the field of epidemiology?

A)Pathology of infectious diseases.
B)Patterns of infectious disease spread.
C)The causes of infectious diseases.
D)The study of spread patterns of all diseases.
E)The causes of all diseases.

Question 10

Examine Table 18.1 in the text.Which symptom or sign would be LEAST definitive in diagnosing one of the diseases listed?

A)anemia
B)Fever
C)Decreased CD4+ cell count
D)diarrhea
E)All are equally diagnostically significant

Question 11

What often determines the host range of a pathogen?

A)It's ability to replicate inside a host cell.
B)The exit strategy of the pathogen.
C)The ability of pathogen to attach to a host cell.
D)It's ability to destroy antibody.
E)Nutrient availability.

Question 12

Neisseria gonorrheae causes disease through:

A)latency of some bacterial cells within host tissues
B)creation of ever-changing VSG glycoproteins
C)ability to destroy immune defenses in the host
D)production of exotoxin released from its Gram positive cell wall
E)production of xylanase,destroying plant conductive tissue

Question 13

How does vertical transmission of a pathogen occur?

A)By an aerosol route.
B)As a result of an insect bite.
C)From mother to offspring.
D)By a sexual route.
E)By ingesting contaminated water.

Question 14

What does a high case-to-infection ratio (CI)indicate?

A)That the disease is usually fatal.
B)That most people infected by the pathogen will develop the disease.
C)That most people infected by the pathogen will not develop the disease.
D)That the disease is usually very mild.
E)That the pathogen is transmitted by an aerosol route.

Question 15

All of the following are components that may be used by a pathogen for attachment to a host cell EXCEPT:

A)pili.
B)lipoteichoic acid.
C)attachment proteins.
D)chitinases.
E)surface glycoproteins.

Question 16

A contagious disease is MOST likely to be spread via :

A)Sexual transmission
B)Blood-to-blood contact
C)Contaminated blood
D)Contaminated medications and dressings
E)Airborne transmission

Question 17

Pathogens that have the ability to change their surface antigens are better able to do which of the following?

A)acquire nutrients
B)evade host defenses
C)attach to host cells
D)exit the host successfully
E)enter host cells

Question 18

Which of these would need to occur for a disease to be considered communicable?

A)A susceptible host encounters an infectious agent.
B)An infectious agent colonizes a host.
C)An infectious agent colonizes a host and can be transmitted to another host.
D)An infectious agent causes damage to the host.
E)An infectious agent causes damage to the host and can be transmitted to another host.

Question 19

Term for pathogen properties that aid it in causing disease.

A)virulence factors
B)pathogenics
C)proteases
D)enhancers
E)promoters

Question 20

How is the protozoan Plasmodium falciparum transmitted from host to host?

A)an aerosol route
B)a fomite
C)contaminated food or water
D)a vector-borne route
E)sexual contact

Question 21

Which of these factors contributes to the resistance of SJL/J mice to murine hepatitis virus?

A)Host cell receptor variability
B)Immune system defects
C)Pathogen strain variability
D)Anatomical anomalies
E)All are equally confounding

Question 22

Examine this figure closely.What will occur before a Phase 6 outbreak determination is made?

A)Recognition that avaiable medications are inaqequate
B)Recognition that vaccination status within populations is inadequate
C)Air travel from areas of outbreak to unaffected areas
D)Recognition of a significant increase in disease incidence in non-human populations
E)Recognition of zoonotic transmission

Question 23

Given what you know about gene transfer,which of these transfer methods has the greatest potential to naturally facilitate the creation of pathogenicity islands (PAIs)?

A)Conjugation
B)Transformation
C)Transduction
D)Transposition
E)None would assist in PAI formation

Question 24

Which of these factors does NOT complicate the application of Koch's postulates?

A)Host cell receptor variability
B)Diseases with clearcut syndromes (collections of associated signs and symptoms)
C)Pathogen strain variability
D)Obligate intracellular metabolism of some pathogens
E)All are equally confounding

Question 25

Term for the number of NEW cases of a disease within a population during a specific time period.

A)prevalence
B)incidence
C)occurrence
D)infectious dose 50
E)mortality rate

Question 26

Which of these does NOT routinely constitute a "case"

A)a carrier of genital warts virus
B)an animal carrier of foot and mouth disease
C)a child with measles
D)an elderly man with pneumonia
E)a child born to an HIV-diaagnosed woman

Question 27

Which factor assisted Dr.John Snow's epidemiological determination that cholera was occurring as a common source outbreak?

A)he was able to limit access to the source he determined responsible for disease spread
B)his investigation began relatively soon after the first cases were seen
C)he had comparable non-infected sources as a comparative base
D)water access for most individuals was localized
E)all are contributing factors

Question 28

Which of these outcomes is the focus of molecular Koch's postulates?

A)The isolation of the pathogen.
B)The identification of the pathogen.
C)The determination of the LD₅₀.
D)The determination of the ID₅₀.
E)The identification of virulence factor genes.

Question 29

Term for a clustering of virulence genes on the chromosome of a pathogenic microbe.

A)transposon
B)pathogenicity island
C)operon
D)promoter
E)enhancer region

Question 30

Examine this figure closely.What will occur before a Phase 3 outbreak determination is made?

A)Recognition that avaiable medications are inaqequate
B)Recognition that vaccination status within populations is inadequate
C)Air travel from areas of outbreak to unaffected areas
D)Recognition of a significant increase in disease incidence in non-human populations
E)Recognition of zoonotic transmission

Question 31

Term for newly identified infectious diseases or those with a recent significant increase in incidence.

A)emerging diseases
B)new diseases
C)modern diseases
D)future diseases
E)special diseases

Question 32

Which of these is true of an endemic disease?

A)It quickly appears and then disappears in a population.
B)It is present in a population at numbers higher than expected.
C)It is always epidemic on a worldwide scale.
D)It is constantly present in a given population.
E)It is spread by an animal vector.

Question 33

Which of these is an example of a common-source epidemic?

A)A single case of H1N1 influenza is reported in a small town.
B)A prison has a higher rate of tuberculosis than is typical.
C)A number of children show up at school with measles.
D)Several cases of food poisoning from a wedding.
E)A local hospital sees cases of several different "staph" infections in a week

Question 34

Which one of the following statements is NOT one of Koch's postulates?

A)Identify the suspected microbe in every person with the disease.
B)Isolate the suspected microbe in pure culture.
C)Identify virulence factors from the isolated microbe.
D)Inoculate the isolated microbe into a susceptible host to see if it causes the disease.
E)Recover the microbe from the experimentally inoculated host.

Question 35

What is the prevalence rate of a disease?

A)The number of cases of the disease within a specified number of the population.
B)The number of deaths due to an infectious agent.
C)The ratio of the number of deaths to the number of individuals with the disease.
D)The total number of cases of a disease.
E)The number of deaths within a population.

Question 36

Examine this figure closely.What will occur before a Phase 1 outbreak determination is made?

A)Recognition that avaiable medications are inaqequate
B)Recognition that vaccination status within populations is inadequate
C)Air travel from areas of outbreak to unaffected areas
D)Recognition of a significant increase in disease incidence in non-human populations
E)Recognition of zoonotic transmission

Question 37

Dengue fever virus is spread via a mosquito in which part of its life cycle must take place.This makes the mosquito a/an:

A)Mechanical vector
B)Biological vector
C)Fomite
D)Reservoir
E)Symboint

Question 38

Term for an epidemic that occurs on multiple continents.

A)endemic disease
B)outbreak
C)pandemic
D)emerging disease
E)re-emerging disease

Question 39

Which disease listed below is NOT an example of a propagated disease?

A)measles
B)influenza
C)salmonellosis
D)tuberculosis
E)chicken pox

Question 40

Which of these factors complicates the application of Koch's postulates?

A)Host cell receptor variability
B)Diseases with clearcut syndromes (collections of associated signs and symptoms)
C)Antibiotic resistance of pathogens
D)International travel
E)All are equally confounding

Question 41

Which of these agencies collates information regarding notifiable disease incidence in the United States?

A)World Health Organization
B)Food and Drug Administration
C)Environmental Protection agency
D)Centers for disease Control and Prevention
E)Border Infectious Disease surveillance

Question 42

Bacterial defenses against cellular infection include: (Select all that apply)

A)latency of some bacterial cells within host tissues
B)CRISPR-Cas system
C)ability to destroy immune defenses in the host
D)production of exotoxin released from its Gram positive cell wall
E)production of restriction-methylation systems

Question 43

Which of these choices represent symptoms? (Select all that apply)

A)Fever
B)Nausea
C)Fatigue
D)Muscle pain
E)Swelling

Question 44

The influenza mortality rate rises from the yearly 3% average to 12% one winter season in Wisconsin.This would make the occurrence likely to be termed as a/an: (Select all that apply)

A)epidemic
B)outbreak
C)endemic
D)pandemic
E)none is a correct term

Question 45

The emergence of HIV/AIDS disease was most likely a result of:

A)an increase in virulence of an existing human retrovirus.
B)a change in human behavior that allowed the virus to spread.
C)a mutation in an existing retrovirus that allowed for increased spread between humans.
D)a rare zoonotic transfer of a retrovirus strain to humans.
E)an increase in homosexual activity among humans.

Question 46

Primary pathogens are distinguished from opportunistic pathogens in that they always cause a more severe disease.

Question 47

Genome comparisons of which strains contribute to the theory that HIV strains may have arisen independently from SIV strains over time?

A)HIV-1/SIVsmm,HIV-1/SIVcpz
B)HIV-2/SIVsmm,HIV-2/SIVcpz
C)HIV-2/SIVsmm,HIV-1 M/SIVcpz
D)HIV-2 O/SIVsmm,HIV-1/SIVgorilla
E)None provide sequence evidence to support this theory

Question 48

The CI (case to infection ratio)index can be used to estimate: (Select all that apply)

A)Pathogenicity
B)Virulence
C)Attenuation potential
D)number of likely deaths in an outbreak
E)number of likely disease cases in an outbreak

Question 49

Which of these agencies plays the major role in epidemiological surveillance in the USA?

A)World Health Organization
B)Food and Drug Administration
C)Environmental Protection agency
D)Centers for disease Control and Prevention
E)Border Infectious Disease surveillance

Question 50

Enterohaemorrhagic Shiga toxin influences cellular

A)transcription
B)translation
C)DNA replication
D)Glycolysis
E)Immune capability

Question 51

Pathogenic E.coli strain O157:H7 evolved from a non-pathogenic strain as a result of this genetic change.

A)A mutation in a virulence gene.
B)A mutation that resulted in antibiotic resistance.
C)The acquisition of virulence genes from Shigella.
D)The use of antibiotic supplements in animal feeds.
E)A mutation that resulted in increased capsule production.

Question 52

A single mutation in a pathogenic gene may cause the pathogen to become avirulent.

Question 53

The emergence of Lyme disease was most likely a result of:

A)an increase in virulence of the spirochete.
B)a change in human activity that allowed for an increased risk for contact with the pathogen.
C)a mutation in an existing spirochete that allowed for increase spread between humans.
D)a rare zoonotic transfer of the spirochete strain to humans.
E)an increase in the tick population.

Question 54

This is an example of a pathogen that has become more of a threat because it is increasingly harder to control with antimicrobials.

A)MRSA
B)E)coli O157:H7
C)HIV/AIDS
D)Ebola virus
E)Measles virus

Question 55

The discussion in this section of Shiga toxin's beneficial contribution to the survival of E.coli O157: H7 within its host leads us to speculate that the toxin may be part of a/an:

A)Surface receptor complex on the bacterial cell surface
B)Transcription activating complex
C)Translation stimulating peptide
D)DNA polymerase complex
E)Flagellar antigen complex

Question 56

This is an example of a pathogen that has become more of a threat because its host range and virulence have increased

A)MRSA
B)E)coli O157:H7
C)HIV/AIDS
D)Ebola virus
E)Measles virus

Question 57

Polio can be considered as which type(s)of disease: (Select all that apply)

A)infectious
B)communicable
C)contagious
D)primary
E)opportunistic

Question 58

What influenced the decision to halt the Marshall and Warren demonstration that Helicobacter pylori before all of Koch's postulates were satisfied?

A)Inoculating humans with pathogens in a deliberate manner was a questionable practice
B)The unavailability of any cure for the disease
C)The difficulty culturing the microbe
D)The fact that stopping at the stage reached had always been the documented approach
E)Antibiotic resistance of Helicobacter pylori

Question 59

Given the knowledge you gave gained regarding the increasing incidence of Lyme disease,when do you think that most cases are likely to occur?

A)Winter
B)Spring
C)Summer
D)Fall
E)Equal incidence throughout the year

Question 60

Cats suffer(ed)disease caused by the pathogen(s): (Select all that apply)

A)MEV
B)FPLV
C)CPV 2
D)CPV2a
E)CPV2b

Question 61

The incidence of a disease is the number of new cases of the disease in a population over a specific period of time.

Question 62

The replication of a microbial pathogen on or within a host is called a(n)__________________.

Question 63

The measure of the ability of a pathogen to cause severe disease in a host is called _______________.

Question 64

The number of deaths due to a specific disease over a specified number in the population is referred to as the ______________ rate.

Question 65

Endotoxins are toxins that are made in the cell and excreted to the external environment.

Question 66

Most pathogens need to avoid host defenses and attach to host cells before they are able to replicate and establish the disease state in the host.

Question 67

Koch's Postulates still play an important role today in identifying the causative agents of emerging diseases.

Question 68

A(n)________________ is a toxin made inside the pathogen and excreted into the external environment.