though I told her mice are supposed to be out by the garden, she didn’t like them at all. Maybe she went out and got some mouse poison. Do you think that could have made her sick?
AG:
It’s possible, but I doubt it. I don’t want to take any more of your time. Thank you so much for talking with me; you’ve given me some really useful information. Maybe we could take a look at the garden shed on my way out?
Master 2.4c
Copyright © 1999 by BSCS and Videodiscovery, Inc. Permission granted for classroom use. Updated 2012.
Master 2.4d
Copyright © 1999 by BSCS and Videodiscovery, Inc. Permission granted for classroom use. Updated 2012.
Epidemiology Report Form E763
Interview Transcript
Investigator: L. Morton
Victim’s Sex and Age: Male, 46 years
Interview with: Sister-in-law
Date of Interview: October 21
LM:
Thank you for taking this time to talk with me. I’ll try to be brief, but any information
you can give me about your brother-in-law’s activities before he became ill could help us
deter mine what caused his death and how to prevent more deaths like his from occurring.
Sister-in-law: Of course … my husband just couldn’t do this; his brother’s death was just so sudden ….
LM:
I understand. Tell me, when did your brother-in-law first complain of not feeling well?
Sister-in-law: I remember exactly. Bill was never sick, you see—at least, nothing more than a cold …
that’s part of why this is all so shocking. He and John—that’s my husband—had fin ished
the harvest early, on October 8. I was so pleased; it had been such a good year. But I’ve
been married to a farmer long enough to know that their work is never done! Bill and
John decided since the weather was still good and they had time before the snows, they’d
just go ahead and reroof the old barn. They started right in, putting in long, hard days
just like during harvesting. Bill usually had dinner with us since he’s not married, and I
know he just went back out to work on the barn after dinner, even though I insisted John
stay home and spend some time with us. Well, two days after they started on the roof,
Bill complained to John that he was exhausted and not feeling well. What else would you
expect after all that work! But when I checked on him the next day, he really looked bad,
had a fever, and was having trouble breathing. We got him to the hospital that day,
and … well, you know the rest.
LM:
Did your brother-in-law live with you and your family?
Sister-in-law: Oh, no. He lived in the little house … you see, this is a family farm; the boys inherited it from their folks. My husband grew up in this house and, after we married, we lived in the
little house for a while until my in-laws retired and moved to Arizona. By then we’d had
our first baby, so we moved in here and Bill moved to the little house.
LM:
I see. Would it be possible for me to see your brother-in-law’s home? Maybe something
would give me a clue about what caused his death.
Sister-in-law: Oh, of course, we have a key. We’ve only gone in long enough to get a funeral suit . . .
(sob) … we haven’t been up to going in to pack up Bill’s stuff, so everything should be
pretty much as it was. Would you like to see the barn they were working on too?
LM:
Yes, that would be helpful. Do you have livestock in the barn?
Sister-in-law: No, it’s a hay barn, mostly. A little bit of equipment. We used to have a cat out there—
really helps with the rodent population!—but the poor old thing died last spring and we
haven’t gotten another one yet.
LM:
Thank you for your time. We’ll just take a look at the barn and your brother-in-law’s
home and then I’ll be out of your way.
Master 2.4e
Copyright © 1999 by BSCS and Videodiscovery, Inc. Permission granted for classroom use. Updated 2012.
Epidemiology Report Form E4
Investigation of Victim’s House
Victim’s sex and age: Male, 46 years
1.
Description of dwelling
Victim lived alone in a small farmhouse 2 miles from his brother & family who
live in the larger house on the family farm. The 2-story farmhouse had a kitchen,
living room, & 1 bedroom & bath downstairs; upstairs were 2 additional bedrooms.
House also had a small root cellar.
2.
Condition of dwelling
Neither upstairs room appeared to have been used recently; one was used as a
storage room, the other was a study. Living room was tidy, with newspapers
scattered on ottoman. Kitchen was clean with little food in refrigerator: milk,
apples, oranges & package of cheese. Mouse & rat poisons found in lower cupboards.
Bed was unmade, but the bedroom was otherwise neat. Root cellar seemed unused,
although mouse & rat poison had also been put out there.
3.
Unusual chemicals or equipment found
Typical household chemicals found (detergent, cleanser, window cleaner, bleach),
in addition to the mouse & rat poison.
4.
Other comments
Also examined the barn the victim had re-roofed prior to death—a wood
construction originally built about 50 years aqo. Used mostly for storing hay, also
housed tools & some smaller pieces of farm equipment. Found a dish—apparently
used for water for cats.
Date of investigation: 10-21
Signature of investigator:
Master 2.4f
Copyright © 1999 by BSCS and Videodiscovery, Inc. Permission granted for classroom use. Updated 2012.
Epidemiology Report Form E4
Investigation of Victim’s House
Victim’s sex and age: Male, 19 years: female, 24 years
1.
Description of dwelling
The first victim lived with his mother in a rural area, about 3 miles from the
nearest town. The second victim, a college student & sister of first victim,
visited the home prior to becoming ill. Trailer was small, including a
kitchenette, smallliving/dining area, two bedrooms, and one bathroom.
2.
Condition of dwelling
Trailer was somewhat cluttered with victim‛s clothes and books; dirty dishes
were in sink and carton of milk and open loaf of bread were left on table.
Mother had moved to her sister‛s home following her son‛s death. I presume
trailer had been vacant since then. Mouse feces gave evidence of
rodent infestation.
3.
Unusual chemicals or equipment found
None. Only typical household chemicals were found (dishwashing detergent,
floor wax, scouring powder, etc.) No unusual equipment or supplies found.
Five mouse traps werefound on the premises; one had caught a mouse.
4.
Other comments
Victim‛s mother & aunt refused interviews. Learned from aunt‛s neighbors
that, even prior to moving in, the victim‛ mother spent most nights at her
sister‛s home in town where she was nearer to her job.
Date of investigation: 10-25
Signature of investigator:
J. McDonald
Master 2.4g
Copyright © 1999 by BSCS and Videodiscovery, Inc. Permission granted for classroom use. Updated 2012.
Master 2.4h
Copyright © 1999 by BSCS and Videodiscovery, Inc. Permission granted for classroom use. Updated 2012.
Notes from the Physician’s Investigation
Physicians are typically the individuals who first encounter and report a mysterious disease.
They may col lect information on the symptoms exhibited by victims and use that information to suggest possible causes.
Work with your fellow experts to review the documents in the Physician’s File and complete this form. When your group meets again, you will pool your information to create a final report.
Disease Symptoms
Suspected Cause
Evidence:
Other Notes about the Disease
Master 2.5
Copyright © 1999 by BSCS and Videodiscovery, Inc. Permission granted for classroom use. Updated 2012.
Notes from the Laboratory Scientist’s Investigation
Laboratory scientists isolate and examine bacteria, viruses, and other infectious agents from samples of the victims’ tissues and characterize those agents. They also test for antibodies against likely infectious agents in the victims’ blood. They may also check possible vectors (nonhuman carriers for antibodies) and con duct tests to see what drugs will kill or limit the growth of the agent.
Work with your fellow experts to review the documents in the Laboratory Scientist’s File and complete this form. When your group meets again, you will pool your information to create a final report.
Disease Symptoms
Suspected Cause
Evidence:
Suspected Route of Transmission of Infectious Agent
Evidence:
Other Notes about the Disease
Master 2.6
Copyright © 1999 by BSCS and Videodiscovery, Inc. Permission granted for classroom use. Updated 2012.
Notes from the Field Researcher’s Investigation
Field researchers interview victims or victims’ family members and visit victims’ homes,
workplaces, or other places where they spent time to identify commonalities among victims that may give clues about the disease. They also collect information about unique environmental
events that coincided with outbreaks of the disease.
Work with your fellow experts to review the documents in the Field Researcher’s File and
complete this form. When your group meets again, you will pool your information to create a final report.
Disease Symptoms
Suspected Route of Transmission of Infectious Agent
Evidence:
Relevant Environmental Factors
Other Notes about the Disease
Master 2.7
Copyright © 1999 by BSCS and Videodiscovery, Inc. Permission granted for classroom use. Updated 2012.
Mystery Disease 1 Final Report
Name: ____________________
Pool the information from all members of your group to complete each item below.
Disease Symptoms
Suspected Cause
Evidence:
Suspected Route of Transmission of Infectious Agent
Evidence:
Relevant Environmental Factors
Recommendations for Prevention of Disease
Classify This Disease As
emerging re-emerging
endemic
Evidence:
Master 2.8
Copyright © 1999 by BSCS and Videodiscovery, Inc. Permission granted for classroom use. Updated 2012.
Mystery Disease 2 Final Report
Disease Symptoms
Initial symptoms are fever, fatigue, headache, and swol en lymph nodes, typical y fol owing the appearance of a distinctive, expanding, ringlike rash. Within four weeks to a year or more, swel ing or pain in the large joints occurs, resulting in chronic arthritis.
Suspected Cause
A spirochete type of bacteria
Evidence:
People diagnosed with this disease have antibodies against the spirochete, whereas
people without the disease do not.
Suspected Route of Transmission of Infectious Agent
Spirochete bacteria infect humans through bites from infected deer ticks.
Evidence:
Many people diagnosed with the disease recall a distinct rash radiating from the site
of a tick bite; spirochetes were found in 61 percent of Ixodes dammini ticks (deer
ticks), the type of tick suspected of biting victims of the disease.
Relevant Environmental Factors
Most cases occurred among suburban dwel ers living in recently established residential areas near woods. Peak incidence of new cases of the disease occurs in summer and early fal ; some research studies predict peak years for the disease will be two years fol owing heavy acorn production.
Recommendations for Prevention of Disease
Wear socks, long pants, and long-sleeved shirts in wooded areas and check careful y for ticks after leaving the woods; if rash described above appears, see a physician for diagnosis and antibiotic treatment (if diagno sis is positive).
Classify This Disease As
emerging re-emerging
endemic
Evidence:
The characteristics of the spirochete isolated from deer ticks did not match any
known spirochetes.
Master 2.9
Copyright © 1999 by BSCS and Videodiscovery, Inc. Permission granted for classroom use. Updated 2012.
Mystery Disease 3 Final Report
Disease Symptoms
Persistent fever, headache, fatigue, sore throat, vomiting and diarrhea, chest and abdominal pain; in some cases, bleeding from body orifices occurs.
Suspected Cause
A virus in the arenavirus family
Evidence:
Specimens from victims failed to react with antibodies against more than 250
different viruses; one weak reaction was found against antibodies produced in
response to a virus in the arenavirus family.
Suspected Route of Transmission of Infectious Agent
(1) Through close contact with hospitalized victims of the disease. (2) Through contact with urine and feces of the Mastomys natalensis rat.
Evidence:
(1) clusters of disease cases that occurred in hospitals could be traced to an initial,
hospital ized victim; (2) the virus found in victims of the disease was found in
M. natalensis and no other animals tested.
Relevant Environmental Factors
The main competitor of M. natalensis is the more aggressive rat Rattus rattus. Where R. rattus is eliminated by antirodent control measures such as poisoning, M. natalensis may move into an inhabited area.
Recommendations for Prevention of Disease
Avoid contact with M. natalensis rats and their urine and droppings.
Classify This Disease As
emerging re-emerging endemic
Evidence:
Tests of antibodies from victims against more than 250 known viruses showed only
one weak reaction, indicating the disease was caused by an unknown virus.
Master 2.10
Copyright © 1999 by BSCS and Videodiscovery, Inc. Permission granted for classroom use. Updated 2012.
Mystery Diseases Summary Table
Name: ____________________
Infectious
Emerging,
Relevant
Agent
Re-emerging, or
Environmental
Mystery Disease
Transmitted by
Endemic?
Factors
1
2
3
1. An important reason for the emergence of new diseases is . . .
2. This means that to reduce the chances of new epidemics among people, we should . . .
Master 2.11
Copyright © 1999 by BSCS and Videodiscovery, Inc. Permission granted for classroom use. Updated 2012.
Bacterial Growth Experiment
Pseudomonas fluorescens, the bacterium used in the laboratory exercise you will begin soon, does not cause disease in healthy people. However, people who have weakened immune systems
should not have contact with most microorganisms or with people who handle those organisms.
Your immune system may be weakened if you are undergoing antibiotic therapy, if you are taking immunosuppressive drugs or drugs for cancer treatment, or if you have AIDS or are HIV-positive. If you have a weakened immune system for these or any other reasons, let your teacher know and he or she will provide you with an alternative experience that is safer for you.
Follow the directions below to test the hypothesis using the bacterial species Pseudomonas fluorescens and the antibiotic kanamycin. The flow chart on Master 3.1c provides an overview of the experiment.
Hypothesis (insert here): _______________________________________________________
DAY 1
1. Collect the following materials from your teacher:
1 test tube culture of P. fluorescens (the parental culture)
1 test tube containing nutrient broth
1 test tube containing nutrient broth with kanamycin
1 nutrient agar plate
1 nutrient agar plate with kanamycin
You will need the following materials at your laboratory station: 4 sterile 1-milliliter pipets, pipet pump or bulb, container with disinfectant for disposing of used pipets, Bunsen burner, grease pencil for label ing, and beaker of alcohol with a bent glass rod spreader.
2. For your safety and the success of your experiment, you must use aseptic techniques when handling bacterial cultures. You must also discard used cultures safely. Your teacher will explain and demonstrate aseptic techniques and indicate where you should discard your used cultures (with caps and lids in place). Your teacher will decontaminate all of the cultures before disposal.
Swirl the P. fluorescens culture gently to distribute the bacterial cells evenly. Then, follow your teacher’s instructions for maintaining sterile conditions while transferring 0.1 milliliter from the culture into the test tube of nutrient broth and into the test tube of nutrient broth with kanamycin.
Label the first test tube “A,” the second test tube “B.”
3. Swirl the P. fluorescens culture again and follow your teacher’s instructions to deposit 0.1 milliliter from the culture on each of the nutrient agar plates. Use a sterile, bent glass rod to spread the culture evenly over the surface of the plates. Label the nutrient agar plate “1” and the nutrient agar plate with kanamycin “2.”
4. After the culture has soaked into the plates (about 5 to 10 minutes), invert the plates and incubate them and the two broth cultures at 25°C (77°F) for two to three days.
Master 3.1a
Copyright © 1999 by BSCS and Videodiscovery, Inc. Permission granted for classroom use. Updated 2012.
DAY 2 (2–3 days later)
5. Retrieve the broth cultures (A and B) from the first session and collect 2 new nutrient agar plates and 2 nutrient agar plates with kanamycin. Check that you have 4 sterile 1-milliliter pipets, pipet pump or bulb, pipet disposal container, Bunsen burner, and alcohol with a bent glass rod spreader.
6. Swirl culture A gently and follow the procedure in Step 3 to prepare two plates, one nutrient agar plate and one nutrient agar plate with kanamycin. Label the first plate “3” and the second plate “4.”
7. Swirl culture B gently and repeat Step 6 using samples from this culture. Label the nutrient agar plate
“5” and the nutrient agar plate with kanamycin “6.”
8. After the culture has soaked into the plates, invert them and incubate them at 25°C for two or three days. Dispose of the A and B cultures as your teacher directs.
DAY 3 (2–3 days later)
9. Collect all six plates and draw the amount of bacterial growth on each plate on the flow chart.
Master 3.1b
Copyright © 1999 by BSCS and Videodiscovery, Inc. Permission granted for classroom use. Updated 2012.
Step 9: Collect plates and record results above by drawing the amount of bacterial grown on each plate.
Master 3.1c
Copyright © 1999 by BSCS and Videodiscovery, Inc. Permission granted for classroom use. Updated 2012.
Discussion Questions for the Bacterial
Growth Experiment
Name: ______________________
Refer to the results from your bacterial growth experiment as you answer the following questions.
1. Compare the bacterial growth on the two plates from the parental culture (Plates 1 and 2). Which has more growth? Explain why. How do you explain the presence of bacteria on the plate containing kanamycin?
2. Compare the growth on Plates 3 and 4, which you prepared from culture A (without kanamycin).
How does the growth on the plates with and without kanamycin appear? What does this tell you about the bacteria grown in culture A?
3. Compare the growth on Plates 5 and 6, which you prepared from culture B (with kanamycin). How does the growth on the plates with and without kanamycin appear? What does this tell you about the bacteria grown in culture B?
4. Compare the growth of cultures A and B on Plates 4 and 6 (with kanamycin). Explain how culture B could have so many more resistant bacteria than culture A, even though they both came from the same parental culture.
5. How do you explain the presence of some resistant bacteria in the parental culture and culture A?
Master 3.2
Copyright © 1999 by BSCS and Videodiscovery, Inc. Permission granted for classroom use. Updated 2012.
Debi’s Story
Read the following transcript of an interview conducted in 1999 with Debi French.
The Diagnosis
My name is Debi French, and I’m 23. The winter of 1993, when I had chronic bronchitis,
as I had most of my life, I was not getting any better from the medical therapy. So I went
to the doctor and said, “Fix me. There’s something wrong.”
He did chest X-rays, and that’s when we found out I had tuberculosis.
I was coughing. I was extremely exhausted; I fell asleep in almost every class I had
every day. I lost nearly 50 pounds. Those were the main symptoms—excessive coughing
to the point where, the day I went to the doctor’s office, I coughed till I puked.
We did the chest X-rays, and the doctor reviewed them and then had another doctor
give a second opinion. Then he came in and told me and my mom. … And the first
thing he said was, “Well, you don’t have to go to school.” And the first words out of
my mouth were, “But I have a parade on Saturday I have to march in.”
To say the least, I was not thrilled. My mom was relieved because in her mind, it was
something curable.
At the time, the only thing I knew about tuberculosis was that people had died from it.
And far be it from me to allow myself to die from a little bacteria.
It’s not every day that your typical middle-class white girl, living in suburbia, gets a
disease like this. Somebody in one of my classes had an active case and continued to
go to school, where it spread like wildfire. By the time the testing was complete, they
revealed that there were 12 active cases of tuberculosis and 350 positive skin tests
showing exposure. So in a small school of about 1,200 people, that’s nearly a quarter
of the population.
The Initial Treatment
At first, I was on four different medications, including the antibiotics isoniazid and
rifampin. After six weeks or so, it seemed like they had done their job. My sputum
tests came back negative, so I wasn’t active any more. But I would still have to
continue drug therapy for about a year.
It worked for a while. …
Master 3.3a
Copyright © 1999 by BSCS and Videodiscovery, Inc. Permission granted for classroom use. Updated 2012.
The Treatment Fails
During my senior year—February 14, 1994—I’ll never forget—my doctor called me
and said that the tests that they had been doing to see if I could get off my medication
came back positive. I had an active case all over again.
I spent two weeks in UCLA Medical Center, which included my 18th birthday. After
that, my parents decided that because I wasn’t getting any better, there was no reason
to put me and them and the rest of the family through the torture of my having to stay
in the hospital, when, aside from the fact I had a communicable disease, I was normal.
So they let me go home, and I was home for about six weeks. Still, I wasn’t getting any
better, even on new medications. After six weeks, the health department basically told
my mom that if they didn’t take me to this hospital in Colorado, I was going to die.
A Happy Ending
So I went to Colorado. We had to get a private plane to take us, because when you’re