Microbiology - Chapter 18

[ch 18] Term for an epidemic that occurs on multiple continents.

• endemic disease
• outbreak
• pandemic
• emerging disease

pandemic

[ch 18] What is studied in the field of epidemiology?

• Pathology of infectious diseases.
• Patterns of infectious disease spread.
• The causes of infectious diseases.
• The study of spread patterns of all diseases.

The study of spread patterns of all diseases.

[ch 18] How does vertical transmission of a pathogen occur?

• By an aerosol route.
• As a result of an insect bite.
• From mother to offspring.
• By a sexual route.

From mother to offspring.

[ch 18] How is the protozoan Plasmodium falciparum transmitted from host to host?

• an aerosol route
• a fomite
• contaminated food or water
• a vector-borne route

a vector-borne route

[ch 18] What often determines the host range of a pathogen?

• It’s ability to replicate inside a host cell.
• The exit strategy of the pathogen.
• The ability of pathogen to attach to a host cell.
• It’s ability to destroy antibody.

The ability of pathogen to attach to a host cell.

[ch 18] Term for pathogen properties that aid it in causing disease.

• virulence factors
• pathogenics
• proteases
• enhancers

virulence factors

[ch 18] In order to cause disease, successful infectious pathogens must be able to do ALL of the following except:

• gain entry to the host.
• attach to and/or invade host cells.
• evade host defenses.
• exit the host.
• kill the host.

kill the host.

[ch 18] A contagious disease is MOST likely to be spread via :

• Sexual transmission
• Blood-to-blood contact
• Contaminated blood
• Contaminated medications and dressings
• Airborne transmission

Airborne transmission

[ch 18] What does a high case-to-infection ratio (CI) indicate?

• That the disease is usually fatal.
• That most people infected by the pathogen will develop the disease.
• That most people infected by the pathogen will not develop the disease.
• That the disease is usually very mild.

That most people infected by the pathogen will develop the disease.

[ch 18] Which of these would need to occur for a disease to be considered communicable?

• A susceptible host encounters an infectious agent.
• An infectious agent colonizes a host.
• An infectious agent colonizes a host and can be transmitted to another host.
• An infectious agent causes damage to the host.
• An infectious agent causes damage to the host and can be transmitted to another host.

An infectious agent causes damage to the host.

[ch 18] A case-to-infection ratio of 0.25 indicates

• one in four people have been exposed to the disease.
• one in four people who are exposed to the disease are infected.
• one in four people who are infected develop the disease.
• three of four people are infected upon first exposure to the disease.

one in four people who are infected develop the disease.

[ch 18] More Gram negative bacteria are pathogens than Gram positive, perhaps because

• Gram negative bacteria are better able to attach to host cells.
• Gram negative bacteria are better able to invade host cells.
• Gram negative bacteria are better able to replicate in host cells.
• Gram negative bacteria are better able to avoid the host immune system.

Gram negative bacteria are better able to avoid the host immune system.

[ch 18] In fall 2008, a physician in a small rural community in Alaska, notified the state division of health and human services of a number of adult patients with recently diagnosed pneumonia (n = 10) including three persons who required hospitalization and one who died. Previously, only six sporadic cases of pneumonia had been reported in this state in the last 3 years. Is this considered an outbreak?

• No because it is only 10 cases, a very small number.
• No because it is restricted to just one small community.
• Yes because 10 cases in such a short period of time is well above the average of 2 cases per year.
• Yes because 10 is a lot of cases for a disease like pneumonia.

No because it is restricted to just one small community.

[ch 18] What is the most likely mode of transmission for respiratory infection like pneumonia?

• Vector-borne transmission.
• Food-borne transmission.
• Aerosol transmission.
• Direct contact transmission.

Aerosol transmission.

[ch 18] Infectious diseases are transmitted from host to host, but communicable diseases are transmitted from some common source to a host.

True or False

False

[ch 18] Primary pathogens cause severe diseases and opportunistic pathogens cause less severe, milder illnesses.

True or False

False

[ch 18] Pathogens typically cause disease by killing their host cells.

True or False

False

[ch 18] An endemic disease is one that is typically present in the population.

True or False

True

[ch 18] A common source epidemic occurs when one or a small number of individuals in a population contract a disease and spreads it to others in the population.

True or False

False

[ch 18] Emerging diseases are more virulent because our immune systems have not been challenged by them previously.

True or False

False

[ch 18] An important first step for many pathogens to be able to establish an infection in the host is an effective means of

• Replication.
• Invasion.
• Evasion of host defenses.
• Attachment.

Attachment

[ch 18] The rate of death associated with an infectious disease is referred to as its

• Severity.
• Morbidity.
• Incidence.
• Mortality.

Mortality

[ch 18] Zoonotic diseases are

• diseases found in captive animals.
• diseases passed from one animal species to another animal species.
• diseases passed from one individual to another of the same species.
• diseases passed from animals to humans.

Diseases passed from animals to humans.

[ch 18] Opportunistic pathogens

• cause diseases at every opportunity.
• cause diseases occasionally.
• cause diseases in some individuals, but not others.
• both cause diseases occasionally, and cause diseases in some individuals, but not others.

cause diseases occasionally.

[ch 18] The fact that Mary Mallon (Typhoid Mary) called Salmonella Typhi, but did not show symptoms of the disease indicates

• the strain she carried was attenuated.
• the strain she carried was avirulent.
• she had immunity against the strain.
• she must have been exposed to strain on more than one occasion.

she had immunity against the strain.

[ch 18] Objectively measurable and defined disease manifestations are termed

• Signs
• Symptoms
• Pathogenesis
• Virulence

Signs

[ch 18] Case-to-infection ratio and pathogenicity are ____ correlated.

• Directly
• Indirectly
• Inversely
• Not at all

Directly

[ch 18] The morbidity rate measures

• the ratio of the number of deaths from a given disease to the total number of cases of the disease.
• the total number of individuals infected at any one time in a given population.
• the number of individuals who become ill as a result of exposure to a pathogen within a susceptible population over a specific time period.
• the number of new infected individuals within a susceptible population over a specific period of time.

the number of individuals who become ill as a result of exposure to a pathogen within a susceptible population over a specific time period.

[ch 18] The prevalence rate measure

• the ratio of the number of deaths from a given disease to the total number of cases of the disease.
• the total number of individuals infected at any one time in a given population.
• the number of individuals who become ill as a result of exposure to a pathogen within a susceptible population over a specific time period.
• the number of new infected individuals within a susceptible population over a specific period of time

the total number of individuals infected at any one time in a given population.

[ch 18] Transmission of a pathogen from parent to offspring is termed

• Contact transmission
• Indirect transmission
• Horizontal transmission
• Vertical transmission
• Diagonal transmission

Vertical transmission