Deck 18: Introduction to Infectious Diseases

Question 1

What is the morbidity 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.

Answer 1

A

Question 2

Term for an epidemic that occurs on multiple continents.

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

Answer 2

C

Question 3

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 3

B

Question 4

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 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

Pathogens may cause damage to the host by ALL of the following mechanisms EXCEPT:

A) induction of apoptosis in the host cell.
B) production of an exotoxin.
C) production of an endotoxin.
D) lysis of host cell.
E) replication in the host.

Question 7

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 8

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 9

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 10

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 patterns of all diseases.
E) The causes of all diseases.

Question 11

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 12

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 13

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

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 14

Term for pathogen properties that aid it in causing disease.

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

Question 15

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 16

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 17

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 18

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

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

Question 19

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 20

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 21

Vertical transmission of a pathogenic agent occurs from mother to child.

Question 22

Individuals that are carriers of a particular pathogen but do not develop the disease cannot transmit the pathogen to other individuals.

Question 23

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 24

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 25

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

Question 26

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 27

The ability of Staphylococcus aureus to become antibiotic resistant is referred to as antigenic variation.

Question 28

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

Question 29

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

Question 30

A pathogen that causes disease in a healthy host when displaced from its usual location in the body could be termed opportunistic.

Question 31

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 32

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

Question 33

When the virulence of a pathogen is decreased to such a degree that it no longer can cause disease it is termed a(n)_______________ strain.

Question 34

A fomite is an inanimate object used for the transmission of a pathogenic agent.

Question 35

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 36

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 37

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 38

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

Question 39

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

Question 40

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 41

Give two specific examples of emerging pathogens and explain what factors may have contributed to their emergence.

Question 42

A(n)_____________________ disease is an infectious disease of animals that can be transmitted to a human.

Question 43

When the incidence of a disease occurs at a level higher than expected,it is called a(n)______________.

Question 44

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

Question 45

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

Question 46

Distinguish between a primary pathogen and an opportunistic pathogen.

Question 47

Why is Koch's third postulate sometimes problematic?

Question 48

A(n)_____________ disease is one that is always present in a population.

Question 49

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

Question 50

Borrelia burgdorferi,the agent of Lyme disease,is found in nature in the white-footed mice and deer.Mice and deer are said to be _______________ for this pathogen.