Deck 28: Epidemiology

Question 1

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

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

Answer 1

D

Question 2

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

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

Answer 2

D

Question 3

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.

Answer 3

B

Question 4

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

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

Question 5

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

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

Question 6

An example of a cyclical disease is

A) diphtheria.
B) smallpox.
C) influenza.
D) anthrax.

Question 7

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 8

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

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

Question 9

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 10

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 11

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 12

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 13

The MOST common vectorborne disease in the United States is

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

Question 14

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 15

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 16

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 17

Which body site is preferentially infected by foodborne pathogens?

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

Question 18

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 19

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

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.

Question 21

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 22

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 23

Which disease listed does NOT require quarantine?

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

Question 24

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 25

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

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

Question 26

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 27

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 28

Disease cases that exhibit new syndromes or characteristics or are linked to new pathogens are surveyed through regional laboratories and considered ________ cases.

A) zoonotic
B) index
C) endemic
D) epidemic

Question 29

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 30

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

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

Question 31

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 32

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

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

Question 33

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 34

What is a/are potential reservoir(s)for viruses?

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

Question 35

Middle eastern respiratory syndrome (MERS)is caused by

A) Streptococcus pneumoniae.
B) the influenza virus.
C) a coronavirus.
D) a rhinovirus.

Question 36

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

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

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

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 39

Why did the H1N1 strain of influenza virus cause a 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 40

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 41

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

Question 42

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 43

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

Question 44

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 45

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

Question 46

Many pathogenic organisms require living hosts as reservoirs to survive.

Question 47

In 2003,the majority of AIDS deaths occurred in

A) South America.
B) North America.
C) Europe.
D) Sub-Saharan Africa.

Question 48

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

Question 49

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

Question 50

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 51

"Typhoid Mary" 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 52

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 53

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 54

Pasteurization of milk 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 55

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 56

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

Question 57

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

Question 58

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

Question 59

Epidemiological studies of AIDS in Africa have confirmed that ________ transmission of the virus is the norm in that region.

A) fomite
B) indirect
C) heterosexual
D) homosexual

Question 60

The incidence of HIV among hemophiliacs and transfusion recipients has remained constant since 1994.

Question 61

Food and water are considered disease vehicles.

Question 62

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

Question 63

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

Question 64

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 65

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

Question 66

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 67

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

Question 68

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

Question 69

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

Question 70

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

Question 71

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

Question 72

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

Question 73

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 "magic bullets" of chemotherapy and immunization to control infectious disease are readily available.

Question 74

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

Question 75

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

Question 76

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 77

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

Question 78

What happened in Australia when rabbit hemorrhagic disease virus was released to control the rabbit population?

Question 79

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

Question 80

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?