Deck 29: Epidemiology

Question 1

Which body site is preferentially infected by foodborne pathogens?

A) gastrointestinal tract
B) respiratory tract
C) cerebrospinal fluid
D) liver

Answer 1

A

Question 2

Treponema pallidum is extremely sensitive to temperature changes and low moisture, thus it is transmitted

A) by intimate person-to-person contact.
B) by fomites.
C) by vectors.
D) through common sources such as food and water.

Answer 2

A

Question 3

Which of the following is/are considered (a) direct contact infection(s)?

A) syphilis only
B) gonorrhea only
C) skin infections only
D) syphilis, gonorrhea, and skin infections

Answer 3

D

Question 4

Which of the following shows the correct relationship among the epidemiology terms listed?

A) prevalence > incidence > mortality
B) incidence > prevalence > mortality
C) mortality > morbidity > prevalence
D) mortality > incidence > prevalence

Question 5

Potential candidates for biological warfare

A) are generally gram-negative rather than gram-positive.
B) can be virtually any pathogenic bacterium or virus.
C) are eukaryotic rather than prokaryotic.
D) must be genetically engineered to be effective.

Question 6

A disease that is present in unusually high numbers throughout the world is called a(n)

A) endemic.
B) epidemic.
C) sporadic.
D) pandemic.

Question 7

Which of the following emergence factors has contributed to the HIV/AIDS epidemic?

A) climate change
B) rapid pathogen adaptation and change
C) increasing travel to endemic areas
D) exotic pet and meat trade

Question 8

The most common vector-borne disease in the United States is

A) influenza A.
B) Lyme disease.
C) malaria.
D) pneumonia.

Question 9

Which of the following is an example of herd immunity?

A) Brucellosis is no longer found in farm animals in the United States.
B) If 70% of the population is immunized against polio, the disease will be essentially absent from the population.
C) Federal law requires that all cattle not immune to anthrax be destroyed.
D) All farm animals used for food must be immunized against all the common agents of disease that infect humans.

Question 10

A ________ is a disease that primarily infects animals but can be transmitted to humans.

A) nosocomial infection
B) zoonosis
C) vector infection
D) mudurane

Question 11

Which stage of an acute infectious disease occurs between the time the organism begins to grow in the host and the appearance of disease symptoms?

A) acute period
B) decline period
C) infection
D) incubation period

Question 12

The onset of a given epidemic is indicated by a sharp rise in the number of cases reported daily over a brief interval. This indicates that the mode of transmission is

A) host to host.
B) a common source.
C) insect vector.
D) mechanical vector.

Question 13

A marked seasonality to a disease is often indicative of

A) certain modes of transmission.
B) the presence of carriers.
C) a zoonotic infection.
D) a bacterial disease.

Question 14

An example of a cyclical disease is

A) diphtheria.
B) smallpox.
C) California encephalitis.
D) anthrax.

Question 15

Which of the following is NOT a public health measure used to control the transmission of disease?

A) sanitary water and waste disposal methods
B) immunization
C) forced quarantine
D) genetic engineering

Question 16

An inanimate object that transmits infectious agents between hosts is most appropriately called a

A) fomite.
B) carrier.
C) vector.
D) reservoir.

Question 17

Which of the following diseases is NOT normally spread by a common source?

A) measles
B) foodborne diseases
C) waterborne diseases
D) cholera

Question 18

A large number of cases of a particular disease observed in a relatively short period of time in an area that previously experienced only sporadic cases of the disease is known as a(n)

A) pandemic.
B) outbreak.
C) endemic.
D) zoonosis.

Question 19

Based on knowing the history of the HIV/AIDS pandemic, and of efforts to track its spread, you can conclude that it is likely that the incidence of HIV/AIDS among transfusion recipients has

A) increased since the discovery of HIV.
B) decreased since the discovery of HIV.
C) remained the same since the discovery of HIV.
D) never been more than a few individuals per year.

Question 20

Which of the following are NOT vectors important in disease transmission?

A) fomites
B) insects
C) ticks
D) rodents

Question 21

A disease present at a constant low level in a population is described as

A) zoonotic.
B) common source.
C) endemic.
D) epidemic.

Question 22

What is a/are potential reservoir(s) for the rabies virus?

A) water
B) insects
C) bats
D) fomites

Question 23

Diseases that suddenly become more prevalent are referred to as ________ diseases.

A) indirect
B) emerging
C) vector
D) common source

Question 24

Which of the following diseases would be the easiest to control in a human population?

A) an infectious disease with wild animals as a reservoir
B) an infectious disease with humans as the only reservoir
C) an infectious disease with domestic cows as the only reservoir
D) an infectious disease with several possible reservoirs

Question 25

The number of ill individuals within a population is referred to as

A) morbidity.
B) mortality.
C) residency.
D) prevalence.

Question 26

A disease showing a relatively slow, progressive rise followed by a gradual decline in incidence is indicative of a(n)

A) host-to-host epidemic.
B) common source epidemic.
C) biological weapon.
D) endemic disease.

Question 27

Which public health measure(s) is/are most effective against pathogens transmitted through common vehicles?

A) water purification
B) mosquito control
C) food safety regulations
D) water purification and food safety regulations

Question 28

Diseases that are good candidates for eradication have

A) only a human reservoir.
B) no asymptomatic phase.
C) an environmental reservoir.
D) only a human reservoir and no asymptomatic phase.

Question 29

Influenza pandemics occur cyclically because

A) less than 100% of the population is immunized.
B) new strains emerge due to reassortment between bird, swine, and human variants.
C) the vector is seasonal.
D) there are environmental reservoirs that release the virus during particular seasons.

Question 30

A nonliving source of an infectious agent that infects a large number of people is called a

A) fomite.
B) reservoir.
C) vector.
D) vehicle.

Question 31

Cholera is an example of a pandemic disease that

A) has multiple wild animal reservoirs and is thus difficult to eradicate.
B) spreads from a common source and could be controlled with adequate clean water and waste sanitation measures.
C) is spread through direct contact and has only a human reservoir.
D) has recently emerged due to overcrowding in urban centers.

Question 32

Filoviruses (such as Ebola virus) that cause severe hemorrhagic fevers generally have high ________ but low ________.

A) incidence / prevalence
B) prevalence / mortality
C) mortality / morbidity
D) morbidity / mortality

Question 33

With regards to mode of disease transmission, respiratory pathogens are generally ________, and intestinal pathogens are generally spread by contaminated ________.

A) spread by direct contact / vectors
B) spread by indirect contact / carriers
C) more transmissible / needles
D) airborne / food or water

Question 34

Influenza pandemics occur periodically due to characteristics of the influenza virus. How did these characteristics, in this case of the H1N1 strain, contribute to the spread of the swine flu pandemic in 2009?

A) The H1N1 virus had a mutation that increased the mortality associated with infection.
B) The H1N1 virus had a mutation that increased the basic reproduction number of the virus.
C) The H1N1 virus underwent a significant antigenic shift compared to other circulating strains of influenza.
D) The H1N1 virus acquired a new gene from pigs that resulted in increased virulence.

Question 35

Ebola is caused by

A) Streptococcus pneumoniae.
B) the Zika virus.
C) a filovirus.
D) a rhinovirus.

Question 36

The field of study that specifically examines the occurrence, distribution, and determinants of health and disease in a population is

A) microbiology.
B) immunology.
C) epidemiology.
D) virology.

Question 37

Which group of organisms is difficult to control through immunization because of their rapid and unpredictable genetic mutations?

A) vector-borne organisms
B) RNA viruses
C) Archaea
D) DNA viruses

Question 38

Disease ________ is measured by the total number of new reported disease cases within a population over a period of time.

A) incidence
B) frequency
C) morbidity
D) prevalence

Question 39

People who have a subclinical case of a disease are frequently ________ of a particular disease.

A) fomites
B) carriers
C) vectors
D) vehicles

Question 40

Which disease listed does NOT require quarantine?

A) smallpox
B) HIV/AIDS
C) plague
D) cholera

Question 41

Since 1994, HIV is no longer more prevalent in certain groups of people.

Question 42

Reservoirs of infectious disease agents may be either animate or inanimate.

Question 43

Most cases of mosquito-transmitted diseases occur in

A) the summer and fall seasons.
B) tropical and sub-tropical regions.
C) rural areas.
D) tropical and sub-tropical regions or during the summer and fall seasons.

Question 44

Epidemiological studies of AIDS suggest that

A) socioeconomic factors may affect infection risk.
B) the incidence is increasing in recent years.
C) heterosexual women are at lower risk of infection than other women.
D) the virus is no longer changing and evolving.

Question 45

The basic reproduction number of a pathogen

A) can vary during an epidemic based on infection control measures.
B) can be determined experimentally in the lab.
C) is usually high for pathogens that are transmitted through direct contact.
D) can be determined experimentally and is usually high for pathogens that are transmitted through direct contact.

Question 46

Over time, the relationship between a pathogen and a naïve susceptible population tends towards

A) the extinction of the host.
B) the extinction of the pathogen.
C) a balance between host and pathogen such that both are maintained.
D) the extinction of either the host or the pathogen.

Question 47

Many pathogenic organisms require living hosts as reservoirs to survive.

Question 48

Morbidity statistics more precisely define the health of a population than mortality statistics.

Question 49

ʺTyphoid Maryʺ is an example of a ________, because she was infected by the causative agent for typhoid fever yet was asymptomatic.

A) fomite
B) carrier
C) vector
D) vehicle

Question 50

A disease that is constantly present in low numbers is called an acute disease.

Question 51

When the life cycle of a disease agent is dependent on a single host species, the pathogen can be eradicated.

Question 52

The most recent influenza pandemic was in

A) 1918.
B) 1961.
C) 1979.
D) 2009.

Question 53

In the United States and other developed countries, deaths due to infectious diseases are decreasing.

Question 54

An endemic disease is constantly present, usually at low incidence, in a population.

Question 55

In just over a decade of efforts, the World Health Organization (WHO) eradicated smallpox by using worldwide

A) education campaigns.
B) destruction of infected domestic animals.
C) education campaigns and destruction of infected domestic animals.
D) vaccination programs.

Question 56

Pasteurization of milk is a process that reduces bacterial levels and is an example of a disease control measure aimed at

A) preventing host-to-host transmission.
B) controlling the disease vector.
C) preventing common source diseases.
D) eliminating the disease reservoir.

Question 57

In the absence of susceptible hosts, Clostridium tetani would still survive in nature.

Question 58

Diseases can be controlled through immunization even if the percentage of the population that is immunized is less than 100% because

A) vectors can be controlled through other means.
B) most diseases lack reservoirs.
C) of herd immunity.
D) vehicles can be sterilized.

Question 59

The term ________ is applied to strains and preparations of Bacillus anthracis that exhibit properties that enhance dissemination and use as biological weapons.

A) weaponized
B) virulized
C) category A
D) infectious

Question 60

Upper respiratory infectious agents are commonly transmitted from person to person.

Question 61

Many parasites, such as those that cause malaria, use antigenic variation to decrease virulence within a specific host.

Question 62

How can epidemiologist differentiate between common-source and host-to-host epidemics based only on the incidence of disease?

Question 63

Give an example of an acute and a chronic carrier of disease. What disease characteristics allow for chronic carriers to play significant roles in the spread of the disease? How are diseases with chronic carriers controlled?

Question 64

Food and water are considered disease vehicles.

Question 65

A disease transferred by indirect contact with a high basic reproduction number and mortality would be an effective biological weapon.

Question 66

Immunization against endemic diseases is NOT necessary when traveling outside of oneʹs home country or region.

Question 67

To control a disease in a population, 100% immunization is necessary.

Question 68

How might climate change impact the incidence of a disease? Use a specific example to illustrate your answer.

Question 69

Emerging infectious disease will likely affect only developing countries in the near future.

Question 70

You are planning a whitewater rafting vacation in Kenya. Based on what you know about microbiology, what precautions should you take to return in the best of health?

Question 71

What measures would be taken if a case of smallpox were recognized in a world traveler after the individual had debarked from Heathrow airport in England following several days of sightseeing in London?

Question 72

Rodents have been associated with numerous severe epidemics in the past, prompting microbiologist Hans Zinsser in the 1930s to write a book, Rats, Lice, and History, in which he documented the important role of rodents in epidemics. Discuss why rodent control is still desirable, even in an age when it is perceived that the ʺmagic bulletsʺ of chemotherapy and immunization to control infectious disease are readily available.

Question 73

Why are diseases such as rabies that have a wild animal reservoir so difficult to eradicate while other diseases such as brucellosis that reside in domestic animals have been virtually eradicated.

Question 74

Failure to reach equilibrium with a disease agent could result in extinction for a host species.

Question 75

The lower the basic reproduction number of a pathogen, the higher the percentage of immune individuals necessary to provide herd immunity.

Question 76

What are the five stages of a typical infectious disease? During which stage is the host likely to infect others?

Question 77

A disease that is transferred by direct intimate contact with a mortality rate over 90% would be an effective biological weapon.

Question 78

Explain the concept of coevolution in terms of host-pathogen interactions.

Question 79

Changes in food processing and distribution can increase the incidence of new and emerging diseases.

Question 80

List and discuss five factors responsible for the emergence of new pathogens or the reemergence of existing pathogens.