Origin: Chapter 15- Emerging Infectious Diseases, 1
1. The clinic clients respond negatively to the need for a yearly flu shot. They ask why the
medical communities don't just create one shot that will last for several years. Which
explanation should the nurse give?
A) Genetic changes in the bacteria that cause the flu require a rotating course of
antibiotics.
B) Genetic changes make the flu virus resistant to the flu shot from year to year.
C) There is more than one strain of the flu virus and you must be protected from all
of them.
D) The shots last only for 3 to 6 months and must be renewed on a yearly basis.
Ans: B
Feedback:
As microbes reproduce, genetic changes may result in pathogens that are
immunologically distinct from their parental strains. For example, antigenic drift, the
slow and progressive genetic changes that take place in DNA and RNA as organisms
replicate in multiple hosts, causes changes in influenza viruses each year. These
frequent changes that result from antigenic drift mean that there is a new seasonal
influenza vaccine each year. The flu is caused by the influenza virus, not bacteria, so
antibiotics would not be appropriate for treatment. One does not need to be protected
from all strains of the flu virus, only the ones prevalent in the client's area at the present
time. Vaccination shots typically last for years, not for 3 to 6 months.
Origin: Chapter 15- Emerging Infectious Diseases, 2
2. Nursing students in an enclosed classroom begin to become ill with a gastrointestinal
illness. The public health department identifies this occurrence as an emerging epidemic
and isolates the population that is ill. According to microbial adaptation, those who
survive the illness will then do which of the following?
A) Recover with adaptive organism reintroduction into the environment
Page 1
,B) Develop improved defenses against reinfection
C) Become hosts to the organism, which is symbiotic in nature
D) Become carriers of the infection, ultimately leading to an epidemic
Ans: B
Feedback:
Three stages of microbial adaptation and change occur over varying periods of time.
During stage I, an epidemic occurs. The microbes enter a “virgin” population where
hosts have no prior exposure to the organism and have few defenses. This leads to
further spread in the population. Ultimately, survivors are usually left with improved
defenses against reinfection. During stage II, the infection becomes endemic or
continuously present in a geographic area or population of people. Routine childhood
diseases are an example of such infections. During stage III, symbiosis is possible.
Further adaptation occurs, resulting in mutual tolerance and sometimes mutual benefit
for both the microorganism and the host. This is the preferred outcome.
Page 2
, Origin: Chapter 15- Emerging Infectious Diseases, 3
3. Three years after exposure to a virulent form of the flu, a population faces the same flu
strain. The public health department recognizes that there are members of the population
who have not been exposed to the flu strain. Which is most likely to happen?
A) The unexposed population will contract the illness
B) The unexposed population is not likely to contract the illness
C) The unexposed population will contract the illness and reinfect others
D) The flu will reach epidemic proportions and both populations will become ill
Ans: B
Feedback:
If a substantial proportion of people in a population are not susceptible to a
communicable disease, the few people who are susceptible are not likely to be exposed
and contract the illness. This is a process called herd immunity.
Origin: Chapter 15- Emerging Infectious Diseases, 4
4. Which environmental factors are likely to affect the life cycle of disease pathogens and
their vectors and thus disease outbreaks? (Select all that apply.)
A) Temperature
B) Geology
C) Precipitation
D) Humidity
E) Amount of daylight
Ans: A, C, D
Feedback:
Many infectious diseases have characteristic geographic distributions and seasonal
variations. Probably the most common is the influenza virus, which peaks each fall and
winter. Factors such as temperature, precipitation, and humidity affect the life cycle of
many disease pathogens and their vectors, and consequently they can affect disease
outbreaks. Geology, or the types of rocks present in the area, and the amount of daylight
are not likely to affect the life cycle of disease pathogens and their vectors.
Page 3
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