1. Murder by HIV? Grades 5–8 Edition
Michèle I. Shuster Department of Biology New Mexico State University, Las Cruces, NM
Naowarat (Ann) Cheeptham Department of Biological Sciences Thompson Rivers University, Kamloops, B.C., Canada
Laura B. Regassa Department of Biology Georgia Southern University, Statesboro, GA
Licensed image © juliashm - Fotolia.com, ID #

2. Key Concepts and Background
Basic knowledge of HIV and what happens during an HIV infection (see next slides for a brief re-cap)
Genetic relationships and phylogenetic trees
# of genetic differences indicates distance
Reading nodes/common ancestors on phylogenetic trees
See teaching notes for blocks of analysis and background references.

3. HIV Infection Infects, replicates, infects, replicates Every time
Chance for mutation
“Typo” during replication
So within the body
Many RELATED strains of HIV
All descended from original (infecting) strain
All related to each other
All related to the infecting strain
Background/re-cap slide

4. Over time: genetically diverse population
Early
Later
Even Later
Background/ Re-cap slide (each colored symbol represents a viral particle - the different colors designate genetically distinct (due to mutations) viral particles.
-So the amount of virus goes up
-And the genetic diversity of the viral population also increases, due to mutations
In terms of genetic relatedness-
-All the strains present in the infected person are related
-they are all related to the infecting strain (the ancestor)
-and they are all related to each other
-a “family” of virus in an infected person (and amt. of diversity/number of different strains increases with increasing time since infection- more time for replication= more time for mutations to accumulate)

5. The Case

6. State of Louisiana vs. Richard J. Schmidt, MD
Dr. Schmidt was having an affair with a nurse in his office
On-going for 10 years
During this time
He gave her injections
Vitamin B-12
She broke off the relationship (July 1994)
August 4, 1994
He showed up and gave her a “B-12” injection
Against her will

7. January 1995 She tested positive for HIV
Question: Was this a new or old infection?
She was a regular blood donor (HIV testing)
Last blood donation—April 1994
She was HIV negative
Accusation…

8. April 1994 No HIV January 1995 Blood donation HIV positive August 1994
Injection by
Doc/boyfriend
For younger students, this timeline can be made into a handout to which students can add key events as the story is revealed
January 1995
Nurse accused
boyfriend of
infecting her

9. Investigation Doctor’s office Hidden blood-draw record
HIV positive patient
Blood drawn on August 4th, 1994
Blood not sent to lab
Staff were told to hold the tube of blood for the doctor

10. August 4, 1994: Blood drawn from HIV-positive patient at Doc’s office
April 1994
No HIV
Blood donation
January 1995
HIV positive
August 4, 1994
Injection by
Doc/boyfriend
January 1995
Nurse accused
boyfriend of
infecting her

11. Questions Is Nurse’s (victim) HIV related to the patient’s HIV?
Is Nurse’s (victim) HIV related to other HIV strains in LA?
Is Nurse’s (victim) HIV related to other strains of HIV in the U.S.?
Ask students what these questions are getting at.
Do they suggest hypotheses about the source of her HIV?

12. Based on the questions What are some hypotheses?
How can these be tested?
What do you need in order to test these?
Leading students towards thinking about (1) obtaining viral sequences (from nurse, from patient, from LA, from USA), (2) sequencing them, (3) comparing sequences to build a phylogenetic tree

13. Draw Blood and Obtain HIV Sequences
HIV positive patient
Possible source
Nurse
Victim
HIV positive people from the same city in LA
HIV positive person from the U.S. (not LA)

14. If Doctor injected Nurse with Patient HIV…
Which will be most closely related?
Victim HIV and Patient HIV
Victim HIV and LA cases HIV
Victim HIV and USA HIV
Remember that within e.g. the patient and the victim there won’t just be one HIV- there will be a family of related HIV sequences (all related to the original infecting strain) so there will likely be several HIV sequences from each of the victim and the patient.

15. Let’s Build the Tree
Go online to MUSCLE:
We will import HIV sequences
The pol gene
From patient HIV, from Victim HIV, from “other” HIV

16. Copy/Paste Sequences from HIV Sequence file
Paste Here
Then hit “Submit”
These sequences are available as supplemental materials to this case (to retrieve the text file in which they are listed, click on the “Supplemental Materials” tab linked from the case record—see case teaching notes).
Submit
You will need the .txt file from the supplemental materials for the sequences to copy and paste.

17. Wait……

18. Wait… then you will get this— click on “Result Summary”

19. Then click on “Start Jalview”

20. Then you’ll get this Click on Calculate…
An alignment of all the sequences
Patient (possible source)
Victim (the nurse)
LA (random HIV from LA)
USA (random HIV from the US)
Click on Calculate…

21. Calculate
Calculate Tree
Average Distance/ BLOSUM 62

22. Last Common Ancestor between Patient strains and LA strains?
Last Common Ancestor between Patient strains and Victim (Nurse) strains?
Last Common Ancestor between Patient strains and LA strains?
Ask students to interpret the tree, by looking at common ancestors. Note that this slide is animated, so you can ask students to identify each ancestor before the corresponding mark/dot is revealed. This could also be made into a clicker slide: Each question/colored textbox could have the options A, B and C; then the colored dots could be changed to letters A, B, C. So there would be three clicker questions on the slide, asking them to correctly identify the three common ancestors.
Last Common Ancestor between USA strain and LA strains?

23. So which HIV is more closely related to the Nurse’s HIV?
A. Patient HIV
B. LA HIV
C. USA HIV
This could also be made into a clicker question.

24. So what is most likely source of Nurse’s HIV?

25. So what can we conclude?

26. Jury Agreed So did the LA Court of Appeals So did US Supreme Court
Sentence Upheld
50 years of hard labor
Don’t underestimate the power of the phylogenetic tree!

27. August 4th, 1994: Blood drawn from HIV-positive patient at Doc’s office
1998
Doc convicted
50 yrs of hard labor
April 1994
No HIV
Blood donation
January 1995
HIV positive
2002
US Supreme Court
Upheld conviction
2000
LA Court of Appeals
Upheld conviction
August 4, 1994
Injection by
Doc/boyfriend
January 1995
Nurse accused
boyfriend of
infecting her