Case Studies for Human Parasitic and
Infectious Diseases
Introduction:
Each year approximately one third of all human deaths are caused
by infectious and parasitic diseases. In developing countries, that
percentage increases to almost fifty percent. While some of these
diseases have existed for centuries, other viral diseases such as HIV and SARS
have emerged in the human population much more recently. Globalization has
allowed for the transfer of these microbial pathogens across continents. In
order to gain a better understanding of human parasitic diseases, you will
investigate one parasitic or infectious disease and use the information to
create a case study of the disease.
A case study presents readers with a story that includes a problem to solve.
Your job in writing the case study is to provide the readers with enough
information to solve the puzzle without directly given them the answer. In
order to solve the mystery, the readers will need to read, analyze, and
interpret the story. Readers might also need to conduct their own research
before proposing a solution. In order to write a case study, you must become
the expert on the parasitic or infectious disease that you will be writing about.
Once you have collected the necessary information, you must weave your facts
into the form of a story.
Grading Criteria
1. The Case Study is written in the form of a story. 5 points
(The case study is not a list of facts.)
2. The facts given in the case study address the 5 Ws and H. 18 points
Who?
The person designated to have the disease should be from a high-risk
population, if the disease is commonly found within a certain group.
What?
What organism causes the disease?
Where?
Choose a location where the disease is most commonly found.
When?
Was the disease most prevalent in a certain time period? Is it seasonal? If
so, be sure to incorporate that information into your description.
Why?
What did the infected person come in contact with that would cause the
disease? Examples: mosquito bite, drinking contaminated water, etc.
How?
How is a person affected by the disease? List major symptoms/effects.
Summer 2008 Workshop in Biology and Multimedia for High School
Teachers
Harvard University Life Sciences – HHMI Outreach Program
3. The case study ends with a question to answer. 5 points
This assignment must:
 Have a title…that doesn’t give the answer
 be typed in 12 pt. font
 be double-spaced
 include the completed graphic organizer that you used to collect your
information 12 points
Sample:
Grading Criteria
1. Story
5 points
2. 5 Ws and H 18 points
3. Question
5 points
Kevin Smith
Biology
July 15, 2008
Human Parasitic Diseases Case Study
Margaret is a thirty-two year old woman living in Florida. In the fifth week of
her pregnancy she had a miscarriage. In trying to determine why Margaret had
the miscarriage, her doctor learns that Margaret and her husband recently
purchased a kitten from Petco. Not knowing any better, Margaret had been in
charge of cleaning out the litter box. In conducting a blood test, the doctor
discovers that Margaret is infected with cysts from a protist parasite.
What is the most likely cause of Margaret’s condition?
Evaluation:
What grade would you give to this student?
Grading Criteria:
1. Is the case study written in the form of a story?
2. Use the case study to determine if the writer has covered the 5 Ws and
H.
(See chart on next page)
Summer 2008 Workshop in Biology and Multimedia for High School
Teachers
Harvard University Life Sciences – HHMI Outreach Program
3. Does the case study pose a question at the end?
Summer 2008 Workshop in Biology and Multimedia for High School
Teachers
Harvard University Life Sciences – HHMI Outreach Program
Researching the 5Ws and H
Use the case study on the previous page to complete the table.
Factual Information gathered
Translated to part of story
through research
that says:
Most
people
with
a
healthy
immune
system
are
Who?
Who is at
highest risk of
getting the
disease?
What?
What organism
causes the
disease?
able to fight off the parasitic worm that causes
Toxoplasmosis. An unborn child is most likely
to contract the diseases if the mother becomes
infected prior to or during pregnancy.
Toxoplasmosis is caused by the protozoan
parasite Toxoplasma gondii.
Where?
People living in hot, humid climates and lower
altitudes are most likely to become infected.
When?
Toxoplasmosis is the third leading cause of
death due to foodborne illness in the United
States.
Where the
disease is most
commonly
found?
During what
time period
did/does the
disease occur?
Is the disease
seasonal?
Why?
Why did a
person get the
disease? What
did they come
in contact with
to get the
disease? Ex.
mosquito bite,
drinking
contaminated
water, etc.
Cats become infected with Toxoplasma gondii
when they eat infected rodents, birds, or other
small animals. The parasite is transmitted back
into the environment in the cat’s feces. In the
cat’s feces, the parasite is in a microscopic
oocyst form.
In house cats, the oocysts contaminate the litter
box. Cats that are allowed outside also can
contaminate the soil and water. This includes
sandboxes.
Kittens are more likely to spread the oocysts
than mature cats, if the adult cat had been
previously infected.
How?
How is a
person
affected by
the disease?
List
symptoms.
The earlier the transmission occurs, the more
severe the damage is to the unborn child.
Toxoplasma gondii infection can lead to
miscarriages and stillborn births.
Children born with toxoplasmosis may have a
head size that is abnormally large or small.
Resources used to research this disease. (Please include your citations in MLA
format here.)
Summer 2008 Workshop in Biology and Multimedia for High School
Teachers
Harvard University Life Sciences – HHMI Outreach Program
"Toxoplasmosis." Centers for Disease Control and Prevention. 11 Jan. 2008.
Department of Health and Human Services. 15 July 2008
<www.cdc.gov/toxoplasmosis/>.
Name:
Date:
Researching the 5Ws and H for _____________________
Use the table to collect information for your case study.
Factual Information gathered
Translated to part of story
through research
that says:
Who?
Who is at
highest risk of
getting the
disease?
What?
What organism
causes the
disease?
Where?
Where the
disease is most
commonly
found?
When?
During what
time period
did/does the
disease occur?
Is the disease
seasonal?
Why?
Why did a
person get the
disease? What
did they come
in contact with
to get the
disease? Ex.
mosquito bite,
drinking
contaminated
water, etc.
How?
How is a
person
affected by
the disease?
List
symptoms.
Summer 2008 Workshop in Biology and Multimedia for High School
Teachers
Harvard University Life Sciences – HHMI Outreach Program
Resources Used to Research this disease:
Summer 2008 Workshop in Biology and Multimedia for High School
Teachers
Harvard University Life Sciences – HHMI Outreach Program