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From One to Another
VI
ACTIVIT Y OVERVIEW
EW AND
RE
F
SUMMARY
Students watch a segment of the video, A Science Odyssey: “Matters of Life and Death,”
that focuses on the bubonic plague epidemic in San Francisco in the early 1900s. This
story becomes the basis for investigating the relationship between scientific knowledge and the prevention of disease.
KEY CONCEPTS AND PROCESS SKILLS
1.
Tracing the history of science demonstrates how individuals contributed to
the development of modern scientific ideas, and reveals important
interactions between science and society.
2.
Infectious diseases can spread rapidly through a population.
3.
Society sometimes responds to people with infectious diseases with fear,
prejudice, or cruelty.
4.
More complete knowledge of disease transmission has led to improved public
health measures.
5.
Vectors are one way in which some infectious diseases are spread to humans.
KEY VOCABULARY
disease
quarantine
ethics
vectors
infectious
Teacher’s Guide
C-55
Activity 33 • From One to Another
MATERIALS AND ADVANCED PREPARATION
For the teacher
1
A Science Odyssey: “Matters of Life and Death” video
*
1
television monitor
*
1
videocassette recorder
*
1
overhead projector (optional)
*
1
overhead transparency (optional)
*Not supplied in kit
n Teacher’s Note: Always preview the video segments from A Science Odyssey. The
video footage is not divided into sections; however, a clear beginning and end typically mark each segment. Cue to the segment on the bubonic plague, which is approximately 12 minutes in length. The bubonic plague segment can be found near the
start of the tape, immediately following a short introduction to the series. The segment ends as the narrator begins to discuss improvements in public health. Be sure to
end the tape before the segment on pellagra begins. (Different segments of the video
will be viewed at different points of Science and Life Issues.)
A Science Odyssey: “Matters of Life and Death” Table of Contents
Hour 1
Hour 2
Prologue and Introduction
Introduction
Bubonic Plague
Heart Surgery
Pellagra
Organ Transplants
Diabetes
Cancer
Penicillin
Role of Modern Medicine
TEACHING SUMMARY
Getting Started
1.
Contrast the concept of vector with that of a carrier.
Doing the Activity
2.
C-56
Students watch a video segment on the bubonic plague.
Science and Life Issues
From One to Another • Activity 33
Follow–Up
3.
Use the Analysis Questions to summarize ideas presented in the video.
INTEGRATIONS
Social Studies
The treatment of the Chinese immigrants shown in the video can be discussed to
examine the experiences of immigrants to the United States and the treatment of people with infectious diseases.
BACKGROUND INFORMATION
Bubonic Plague
Symptoms of the bubonic plague include chills and fever, vomiting and diarrhea,
headache, and pain in the back and limbs. Victims eventually develop painful hard
lumps called buboes, which are caused by the collection of pus in the lymph nodes of
the groin, armpit, or neck. Eventually blood vessels under the skin burst, causing a
black appearance that led to the name the Black Death for this plague.
Untreated bubonic plague may eventually start to spread in airborne droplets, which
are extremely infectious. This causes pneumonic plague (an infection of the lungs),
which is extremely virulent and spreads quickly. Plague, like many diseases, has an
animal reservoir—the black rat, in which it does not cause serious illness. The rat flea
must be present to act as a vector, transmitting the disease bacterium (Yersinia pestis)
from the rat to the human.
When a disease makes the initial “jump” from animal to human, it tends to cause a
more severe illness than diseases that have been with humankind for hundreds of
years. The plague has become weaker since it first killed approximately one-third of
the population of Europe in 1347–50. Over generations of a host-parasite relationship, the virulence of the parasite and the immune system of its host both adapt,
ensuring the survival and multiplication of both species.
Vectors
Another example of vectors that you can share with students is the deer tick, which
spreads Lyme disease to humans.
Teacher’s Guide
C-57
From One to Another • Activity 33
FOLLOW–UP
TEACHING SUGGESTIONS
3.
GETTING STARTED
1.
Use the Analysis Questions to summarize
ideas presented in the video.
Contrast the concept of vector with that of
When discussing Analysis Question 1, begin to use
a carrier.
the word quarantine instead of isolate. The con-
Review the term vector, which is defined as an
organism that spreads disease-causing germs to
cept of quarantine is further developed in the next
activity.
humans, usually without getting sick itself. Anoth-
Note that Analysis Question 4 can be used to quick-
er disease that is spread by vectors is African sleep-
ly check students’ understanding of the concept of
ing sickness, which is caused by the protist Try-
a vector as well as the concept of disease preven-
panosoma brucei and is spread by the tsetse fly.
tion, which was discussed in the first few activities
Malaria, which is caused by the protist Plasmodium
of this unit.
vivax, is spread by female Anopholes mosquitoes.
Note that the spread of malaria is described in
Analysis Question 4, in which students are asked to
identify the vector.
If students are having difficulty answering the
Analysis Questions, or for review, consider having
the class work together to develop a brief timeline
of events on an overhead projector before watching
You may want to clarify the idea that the term car-
the video a second time. (If you develop this time-
rier is usually applied to people, while vector is used
line with the class before they answer the Analysis
to describe other organisms (typically animals). In
Questions, Questions 1 and 3 might become redun-
both cases, the organism carrying the disease-caus-
dant.) A timeline follows:
ing agent is able to spread it to others, but does not
show any symptoms of the disease.
1894
pendently discover that the bacterium
Yersinia pestis causes the bubonic
DOING THE ACTIVIT Y
2.
Students watch a video segment on the
bubonic plague.
Researchers Yersin and Kitasato inde-
plague.
1900
First bubonic plague epidemic in San
Francisco, California, occurs.
Have students read Analysis Questions 1–3 and
People living in Chinatown were
then watch the video segment on the bubonic
quarantined because it was assumed
plague. Be sure students know that the questions
that the disease is spread by person–
will be answered in the video. It may be helpful to
to–person contact and the first infect-
point out to the class the exact placement of the
ed individuals were Chinese immi-
questions in the context of a timeline of the events
grants.
(see Follow-Up section below).
Teacher’s Guide
C-59
Activity 33 • From One to Another
1900–1906 Researchers in India discover that the
2.
bacterium Yersinia pestis is found in
a. Draw a diagram showing how the bubonic
plague is spread.
the saliva of fleas that live on rats.
Rat infected with Yersinia pestis
When rats come into contact with
humans, the fleas jump hosts and bite
humans, infecting them with plague-
Flea bites rat
causing bacteria.
1906
Flea picks up Yersinia pestis
A major earthquake occurs in San
Francisco and causes a second out-
Flea bites human and injects
Yersinia pestis into blood
break of the plague.
As a result of the discovery of the role of rats in the
plague, buildings in San Francisco were rat-proofed
and
fumigated.
Garbage
was
collected
Human gets bubonic plague
and
removed. Over one million rats were killed, and the
b. Identify the vector of this disease.
spread of plague stopped.
The flea was the vector.
SUGGESTED ANSWERS
3.
TO ANALYSIS QUESTIONS
1.
By 1906, officials knew how the bubonic plague
was spread. What did they do this time to stop the
In 1900, people did not know how the bubonic
spread of disease?
plague was spread. What did officials do to try to
Knowing that plague was spread by fleas that
stop the spread of disease?
lived on rats provided the rationale for a mas-
Because it was assumed that the disease is
sive rat-killing campaign. Houses were “rat-
spread by person-to-person contact and the
proofed” by blocking up holes to the outside
first infected individuals were Chinese immi-
and garbage was picked up to prevent attract-
grants, the people living in Chinatown were
ing rats. Over one million rats were killed.
quarantined. The Chinatown area was physically cordoned off and sick people were sent to
Angel Island in San Francisco Bay. The spread
of the plague stopped, so the quarantine was
considered a success.
4.
a. Malaria, a disease particularly common in Africa,
is caused by a tiny germ known as Plasmodium.
When a female mosquito bites a person infected
with malaria, she sucks up Plasmodium along
with the blood. When she bites a healthy person,
The video also shows houses being sprayed with
Plasmodium germs in her saliva infect that per-
disinfectant, causing some houses to be acciden-
son. What is the vector in this case?
tally burned down. Carbolic acid was poured
into the sewers, which actually increased the
spread of plague by flushing all the rats out.
C-60
Science and Life Issues
The female mosquito is the vector for malaria.
From One to Another • Activity 33
b. Now that you know the vector for malaria, sug-
mon disease in tropical countries. Students
gest two ways that the spread of malaria could be
assigned to research this disease can share their
reduced or prevented.
knowledge with the class.
Students are likely to suggest killing off mos-
In addition, you can discuss ways in which sci-
quitoes (for example, widespread insecticide
entific information can guide public health pol-
spraying), preventing mosquito bites (for
icy. Students may not know that mosquitoes,
example, through the use of insect repellent or,
particularly those species that spread dengue
if possible, by avoiding areas with high con-
fever, breed in stagnant water. One way of
centrations of mosquitoes), or taking medica-
reducing mosquito populations is to prevent
tion to prevent or treat malaria. As a class, you
stagnant water from collecting in or near
may want to discuss what evidence is available
homes. This includes water that may collect in
for determining which methods are effective.
containers after rain (including tires, outdoor
While each of the approaches mentioned is
furniture, etc.) as well as indoor water such as
used to prevent malaria, malaria is still a com-
uncovered aquariums and toilets.
Teacher’s Guide
C-61