Deck 14: Infection, Infectious Disease, and Epidemiology

Question 1

Which of the following types of epidemiology applies Koch's postulates to study a disease?

A) experimental
B) retrospective
C) descriptive
D) analytical
E) systemic

Answer 1

A

Question 2

Diseases that are induced by modern medical procedures are referred to as infections.

A) subacute
B) opportunistic
C) exogenous
D) iatrogenic
E) endogenous

Answer 2

D

Question 3

A person is exposed to desert air containing fungus spores and develops valley fever as a result. Valley fever is an example of a disease.

A) latent
B) contagious
C) chronic
D) noncommunicable
E) subacute

Answer 3

D

Question 4

The incidence of tuberculosis in the year 2000 in the United States was 12.43/100,000 cases. This means

A) there were 12.43 tubercle bacilli per 100,000 microbes in the United States in the year 2000.
B) 12.43 of every 100,000 people died of tuberculosis in the U.S. in the year 2000.
C) 12.43 of every 100,000 cases of tuberculosis were treated in the United States in the year 2000.
D) 12.43 in every 100,000 people in the United States had tuberculosis in the year 2000.
E) there were 12.43 new cases of tuberculosis for every 100,000 people in the United States in the year 2000.

Question 5

A nosocomial disease is a disease acquired

A) by using a contaminated needle.
B) by being bitten by an infected insect.
C) in a health care facility.
D) by having unprotected sexual intercourse.
E) by eating contaminated food.

Question 6

Among the virulence factors produced by Staphylococcus aureus are hemolysin, coagulase, hyaluronidase, and enterotoxin. Which of these factors contribute to the ability of S. aureus to invade the body?

A) hyaluronidase
B) coagulase
C) enterotoxin
D) coagulase and hemolysin
E) hemolysin

Question 7

A strain of Neisseria gonorrhea has a mutation which has caused it to lose the ability to produce fimbriae and become less virulent as a consequence. What function has this pathogen lost?

A) the ability to prevent phagocytes killing it
B) the ability to adhere to cells of the body
C) the ability to establish a latent infection
D) the ability to produce an endotoxin
E) the ability to move from one location in the body to another

Question 8

Which of the following is an example of an exotoxin?

A) coagulase
B) collagenase
C) neurotoxin
D) lipid A
E) streptokinase

Question 9

The fungus Pneumocystis jiroveci is found in the lungs of most people in low numbers, but in immunocompromised people it overgrows, resulting in severe respiratory problems. The fungus is best described as

A) a mutualist symbiotic partner.
B) resident microbiota.
C) a parasite.
D) transient microbiota.
E) both resident microbiota and opportunistic pathogen.

Question 10

Which of the following situations might cause normal microbiota to become opportunistic pathogens?

A) growth of microorganisms on the excreted cellular wastes and dead cells in the large intestine
B) growth of microbes on the surface of intact skin
C) presence of Entamoeba in the lumen of the colon
D) growth of Lactobacillus on the surface of teeth
E) treatment of a cancer patient with radiation

Question 11

In early spring 2009, the CDC reported several dozen cases of novel H1N1 influenza ("swine flu") in the United States. By the summer, the number of confirmed cases was reported as over 40,000. The pattern of novel H1N1 cases in the United States represents a(n) disease.

A) sporadic
B) epidemic
C) opportunistic
D) pandemic
E) endemic

Question 12

Which of the following statements regarding the demonstration of the etiology of disease is FALSE?

A) The suspect agent must be the only potential pathogen present in disease cases.
B) The suspect agent must be isolated and cultured in the laboratory.
C) The suspect agent must cause the disease under investigation when introduced into a susceptible host organism.
D) The suspect agent must be present in all cases of disease.
E) It must be possible to reisolate the suspect agent from the infected experimental host.

Question 13

Chagas' disease is transmitted by a bug with mouthparts that penetrate blood vessels. Which type of exposure does this represent?

A) mucous membrane portal
B) parenteral route
C) fomite
D) contact
E) skin portal

Question 14

In which of the following do the mucous membranes serve as a portal of entry for disease?

A) A pathogen is introduced into the body when the person rubs the eye with contaminated fingers and the pathogen is washed into the nasal cavity by way of tears.
B) A person is bitten by a mosquito that carries the malaria parasite.
C) A person receives an injection with a contaminated needle.
D) Fungi digest the outer layer of the skin.
E) A pathogen crosses from the mother to the fetus by way of the placenta.

Question 15

Mutualism is a relationship

A) where it is difficult to prove the benefits or disadvantages one member of the relationship may provide for the other.
B) where only one member derives benefit from the other.
C) where one member of the relationship may kill the other.
D) where one member of the relationship benefits without hurting the other.
E) that sometimes provides benefits for both members such that one or both parties cannot live without the other.

Question 16

Treatment with high doses of antibiotics may lead to which type of nosocomial infection?

A) zoonosis
B) endogenous infection
C) iatrogenic disease
D) exogenous infection
E) latent infection

Question 17

Which of the following pairings of microbe and disease was disproven using Koch's postulates?

A) hepatitis B and D and liver cancer
B) Haemophilus influenzae and the flu
C) HIV and AIDS
D) varicella- zoster virus and chickenpox
E) Mycobacterium leprae and leprosy

Question 18

Which of the following is NOT an example of symbiosis?

A) protozoa in termites
B) tuberculosis in the human lung
C) tapeworm in the human intestine
D) bacteria in the human colon
E) microbes passing across the placenta to the fetus

Question 19

The bacterium that causes tuberculosis can be expelled from the lungs by a cough and remain viable in the air for an hour or more. If a person inhales the bacteria from the air, what type of transmission has occurred?

A) waterborne
B) indirect contact
C) bodily fluid
D) airborne
E) foodborne

Question 20

The condition called parasitism is characterized as a(n)

A) relationship between two organisms where only one member benefits and the other is unharmed.
B) relationship between two organisms where one member harms the other.
C) relationship between two organisms where both members benefit.
D) nonsymbiotic relationship.
E) unsuccessful microbial invasion due to the presence of preexisting microbes.

Question 21

A pathogen is best described as

A) a microorganism that may cause a disease under certain circumstances.
B) an organism that remains in the body for a short time.
C) any microorganism that causes disease.
D) a source of microbial contamination.
E) a microorganism that remains with the person throughout life.

Question 22

Which of the following stages of an infectious disease is the most severe?

A) the prodromal period
B) the illness period
C) the decline period
D) the convalescence period
E) the incubation period

Question 23

An axenic environment is one

A) in which microorganisms remain present only for a short time.
B) that is a source of contamination.
C) that is free of microbes.
D) contaminated by microbial toxins.
E) in which microorganisms remain with the person throughout life.

Question 24

Microbes known as transient microbiota are

A) organisms that remain in the body for a short time.
B) unsuccessful microbial invaders because of the presence of preexisting microbes.
C) microorganisms that remain with the person throughout life.
D) microorganisms that may cause a disease under certain circumstances.
E) sources of microbial contamination.

Question 25

Which of the following combinations of pathogen and virulence factor is correct?

A) Neisseria gonorrhoeae and endotoxin
B) Streptococcus pyogenes and protein M
C) Staphylococcus aureus and neurotoxin
D) Escherichia coli and cytotoxin
E) Gram- positive bacteria and lipid A

Question 26

Which of the following situations is NOT a way in which a baby acquires normal microbiota?

A) Microorganisms grow in the respiratory tract after the baby's first breath.
B) Microbes enter the nose and mouth when the baby is in the birth canal.
C) The baby acquires the residential microbiota in the colon after the first meal.
D) Staphylococcus epidermidis is transferred from the hospital staff to the newborn after delivery.
E) Microbes cross the placenta during pregnancy.

Question 27

A protozoan and its resident bacteria invade the body of a worm. The bacteria release toxins and exoenzymes that immobilize and digest the worm, and the protozoan and bacteria absorb the nutrients produced. The relationship between the protozoan and the bacteria would best be described as

A) commensalism.
B) parasitism.
C) mutualism.
D) both commensalism and parasitism.
E) a nonsymbiotic relationship.

Question 28

Which of the following is a sign of disease?

A) dizziness
B) cramps
C) nausea
D) headache
E) fever

Question 29

Commensalism is best described as a(n)

A) relationship in which a microorganism causes disease.
B) relationship between two organisms where only one member benefits and the other is unharmed.
C) relationship between two organisms where both members benefit.
D) source of contamination.
E) unsuccessful microbial invasion due to the presence of preexisting microbes.

Question 30

Which of the following diseases may be reduced by improved public sanitation measures?

A) chickenpox
B) cholera
C) HIV
D) rabies
E) malaria

Question 31

The condition known as microbial antagonism may be defined as

A) a relationship between two organisms where only one member benefits.
B) a relationship between two organisms where both members benefit.
C) an unsuccessful microbial invasion due to the presence of preexisting microbes.
D) microorganisms that remain with a person throughout life.
E) a relationship between two organisms where one member harms the other.

Question 32

Two children attend the same daycare, but one child is at daycare in the morning and the other child attends the daycare facility in the afternoon. Both children become ill with fifth disease within a day of each other. How might the pathogen have infected both children?

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

Question 33

Symptoms are

A) objective manifestations of a disease that can be observed by others.
B) objective manifestations of a disease that can be measured.
C) subjective characteristics of a disease that only the patient can feel.
D) laboratory tests used to diagnose a disease.
E) characteristics of a disease, such as sweating.

Question 34

The close contact between newborns and family members allow them to become with microbes that become established as their microbiota. (Choose the most accurate term.)

A) parasitized
B) infected
C) contaminated
D) colonized
E) infiltrated

Question 35

Which of the following is the correct sequence of a disease process?

A) incubation, convalescence, prodromal period, illness, decline
B) illness, convalescence, incubation, prodromal period, decline
C) convalescence, incubation, prodromal period, illness, decline
D) incubation, prodromal period, illness, decline, convalescence
E) prodromal period, convalescence, incubation, illness, decline

Question 36

Which of the following is transmitted by the parenteral route?

A) warts
B) pertussis
C) gonorrhea
D) yellow fever
E) ringworm

Question 37

In the wake of the cyclone that hit Myanmar (Southeast Asia) in 2008, there were widespread reports of typhoid fever. Which of the following was the most likely mode of transmission?

A) aerosols
B) contaminated water
C) contact
D) flies
E) mosquitoes

Question 38

A reservoir is

A) a condition in which organisms remain in the body for a short time.
B) a source of microbes for laboratory testing.
C) a source of microbial contamination.
D) any microorganism that causes disease.
E) an environment that is free of microbes.

Question 39

Aerosols may be involved in transmission of pathogens.

A) fecal- oral
B) waterborne
C) direct
D) droplet
E) vector

Question 40

Which of the following is considered part of the indigenous microbiota of the female reproductive system?

A) E. coli
B) Bacteroides
C) Candida
D) Lactobacillus
E) both Candida and Lactobacillus

Question 41

The large populations of pathogenic microbes found in health care settings contribute to (nosocomial/iatrogenic/epidemic) infections.

Question 42

The study of the cause of disease is known as (epidemiology/etiology).

Question 43

The bacterium that causes cholera is capable of living independently in freshwater. As a consequence, cholera epidemics primarily involve (nonliving/animal/zoonotic) reservoirs.

Question 44

Biological (sources/vectors/carriers) not only transmit pathogens, but also serve as hosts for the manipulation of the pathogen during some phase of the pathogen's life cycle.

Question 45

Which of the following is considered a mechanical vector transmission?

A) cockroach transmission of Shigella
B) flea transmission of Yersinia
C) louse transmission of Rickettsia
D) tsetse fly transmission of Trypanosoma
E) mosquito transmission of Plasmodium

Question 46

The degree to which a microbe is able to cause disease is known as its (morbidity/virulence/toxicity).

Question 47

Nervous system function may be impaired by the action of (endotoxins/neurotoxins/cytotoxins).

Question 48

Staphylococcus bacteria are commonly present in the human nasal cavity but rarely cause disease of the upper respiratory system. This situation is an example of (commensalism/mutualism/parasitism).

Question 49

Lipid A is a(n) (cytotoxin/endotoxin/exotoxin) that stimulates the body to release chemicals that cause fever, inflammation, diarrhea, hemorrhaging, shock, and blood coagulation.

Question 50

The taxonomic approach to classifying disease is based on the

A) means of transmission.
B) type of host for the microbe.
C) severity and duration of the disease.
D) organs or organ systems affected by the disease.
E) type of microbe that causes the disease.

Question 51

Organisms that are resident microbiota are best described as

A) organisms that remain in the body for a short time.
B) microorganisms that remain with the person throughout life.
C) microorganisms that may cause a disease under certain circumstances.
D) any microorganisms that cause disease.
E) microorganisms that never cause disease.

Question 52

Persons with asymptomatic infections may be (contaminants/reservoirs/zoonoses) of disease.

Question 53

Spread of pathogens from one host to another by fomites is an example of (vehicle/direct/indirect) contact transmission.

Question 54

A new influenza strain appears and is spreading rapidly. What measures might be taken by public health agencies to stop the spread?

A) Educate the public, promote vaccination, and treat those who are infected.
B) Educate members of the public about ways to protect themselves.
C) Facilitate access to vaccines.
D) Shut down public transportation.
E) Identify and treat people who are infected.

Question 55

The hepatitis C virus normally establishes a (latent/chronic/subclinical) infection and may be asymptomatic for a decade.

Question 56

Fomites are

A) silent carriers of infectious diseases.
B) animal sources for human pathogens.
C) insects that transmit pathogens from an infected host to a noninfected host.
D) inanimate objects involved in the indirect contact transmission of pathogens.
E) fecal material from infected hosts.

Question 57

The (incubation/morbidity/prodromal) period is the time between infection and the occurrence of the first symptoms or signs of the disease.

Question 58

Toxins that affect the lining of the gastrointestinal tract are (endotoxins/enterotoxins/exotoxins).

Question 59

Virions attach to target host cell by means of (capsules/receptors/ligands).

Question 60

The study of when and where diseases occur is known as (analytical/descriptive/experimental) epidemiology.

Question 61

Koch's postulates can be applied to every infectious disease to identify its causative pathogen.

Question 62

Describe three types of reservoirs of infection in humans. Give an example disease for each type of reservoir.

Question 63

A syndrome is a group of symptoms and signs that collectively characterize a particular disease.

Question 64

What are the different types of symbiosis? List and give a short definition and an example for each.

Question 65

A common cold is an example of a chronic disease.

Question 66

Places in the body where there is no normal microbiota are referred to as (sterile/aseptic/axenic).

Question 67

All diseases go through the stages known as incubation period, prodromal period, and illness.

Question 68

Fomites cause disease by direct contact.

Question 69

Bacterial cells with capsules are resistant to killing by phagocytes.

Question 70

In 2012 a new kind of fungal meningitis (infection of the nervous system) was discovered. Disease occurred among patients who had received steroid injections. Discuss whether these were nosocomial infections: defend your answer. Discuss the route of transmission and what measures public health agencies could take to reduce disease.

Question 71

In commensalism, one member of the relationship harms the other.

Question 72

Normal microbiota may cause disease if they are introduced into an unusual site in the body.

Question 73

Biofilms provide an alternative means for bacteria to attach to surfaces within the body.

Question 74

Researchers have proposed that the herpesvirus responsible for the childhood illness roseola may cause a type of T cell leukemia. Ninety percent of the population has been infected by the virus by two years of age, but the T cell leukemia is relatively rare. The virus can be cultured in the laboratory in tissue culture, but not in mature organisms. Discuss the obstacles to applying Koch's postulates to the etiology of this disease.

Question 75

An infection always leads to disease.

Question 76

Compare and contrast endotoxins and exotoxins.