HIV / AIDS

 U.S. cases:AnnaKatriceLaverneDougLisaJenniferSteve Marie
African cases:NicoleAuxiliaMarieTendayiSafari
Contributed by Karen Klyczek, University of Wisconsin – River Falls

Background:  Human immunodeficiency virus (HIV) causes the disease Acquired Immunodeficiency Syndrome (AIDS).  AIDS is characterized by the inability to mount an effective immune response to bacteria and other pathogens, resulting in a variety of life-threatening infections.  The virus is spread when bodily fluids, such as blood and semen, from an infected person directly enter the bloodstream or tissue fluids of an uninfected person.  For example, unprotected sexual intercourse and sharing needles during injected drug use can spread the virus.  Once in the body, HIV infects and destroys certain white blood cells (called CD4 cells) and impairs the immune system.  It may take years after the initial HIV infection for the symptoms of AIDS to appear.  HIV infection is routinely detected indirectly, via tests which measure whether a person’s blood contains antibodies against HIV; if so, they must have been previously infected with the virus. PCR can also be used to directly measure the amount of HIV in a person’s blood or lymph nodes.  For additional information about HIV/AIDS-related disease, detection methods, treatment, and prevention, visit the CDC’s web site.

Note on HIV testing: Cases are from the early days of the AIDS epidemic in the U.S. and Africa, when Western blotting was used to confirm ELISA screening results. Starting in 2010, other procedures replaced Western blotting as the definitive test for HIV. These procedures are as accurate but produce results more quickly and easily, lessening the chance for false negatives.

Note on videos: These case scenarios are based on real people infected with HIV (except for the Safari case, portrayed by actors).   Each case includes a video, accessed from the Case It web site, showing that person discussing their experience with the disease.   As you study the cases, here are some general questions you might consider:

  • How did this person become infected with HIV?
  • Have others also been infected?  Who else should be tested?
  • How reliable are the tests?
  • How often should someone be tested?
  • Why do people engage in risky behaviors?
  • What impact is the infection having on this person’s life?
  • How can this person prevent further transmission of the virus?
  • What other ethical decisions does this person face?
  • How common is this case?
  • Are there cultural differences regarding attitudes about HIV and prevention?

Video introduction to HIV (from “AIDS: A Changing Epidemic”, copyright 2002 Discovery Education – used with permission)

Analyzing an HIV/AIDS case using the Case It! simulation software includes the following components.  For details about how to use the software, refer to the tutorials linked from the Case It! Home page (left panel) and also the Help window in the software.

  1. Run an ELISA to test blood samples for the presence of antibodies to HIV.   TheELISA involves adding antibody samples to wells of a 96-well plate that have been coated with HIV proteins.  Samples produce color in the wells if they contain antibodies that can bind to the HIV proteins.  An ELISA test is generally considered positive if the color production (absorbance) for a sample is at least twice that of the negative control. Choose the “use antibodies as samples” option when setting up the ELISA.

  2. Since the ELISA has a 1/1000 rate of false positive results, up until 2010 positive ELISA results were confirmed by Western blot (see note on HIV testing above). For the Western blot, HIV proteins are separated by size using polyacrylamide gel electrophoresis.  Then blood samples are tested to see whether they bind specific proteins in the gel.  The HIV proteins visible in the gel  (from largest to smallest, running left to right), include gp160*, gp120, p55, p41, p31 and p24.  The positive control antibody will bind to all of the proteins.  To be considered HIV positive, a sample must bind to two of these three proteins: gp160/gp120*, gp41, and p24.  Any other binding pattern is considered “indeterminate”.  A result can only be called negative if there is no binding to any of the HIV proteins.  (*gp160 is a precursor that includes both gp120 and gp41, before they are cleaved into separate envelope proteins; antibodies that bind gp120 are likely to also bind gp160.)

  3. The viral load test detects virus genetic material in blood or lymph node samples, using a PCR method performed in a 96-well plate.  This test is used to monitor the progress of the disease and to determine the effectiveness of drug treatments.  The DNA samples represent RNA isolated from blood that has been copied to DNA using reverse transcriptase.  PCR primers specific for HIV sequences will amplify HIV DNA and produce fluorescence.  The amount of fluorescence correlates with the number of copies of HIV present in the original sample.  The data are recorded as “viral load values”, i.e. how many copies of the virus were detected.   To run the viral load test, Click the Method button on the 96-well plate and choose PCR (or use the auto-loading feature on the “open & processed” window).

  4. For bioinformatics analysis, Case It has been integrated with MEGA software to perform multiple sequence alignments and build phylogenetic trees.  Each case includes a scenario where building a tree provides additional information that addresses questions about the case.  The DNA samples are complete HIV genomes, and PCR must be performed to amplify a portion of the Env gene to use for alignment and tree building. Important note: use the DNA sequences provided in the Bioinformatics folder for each case, rather than the sequences in the Viral load folder.

CASES FROM THE UNITED STATES

Case A.  Anna is a 27-year-old woman from Guatemala, who is living with her boyfriend and is pregnant with her first child.  A blood test during her second trimester revealed that she was HIV positive.  Anna is surprised, because her first trimester test was negative, and she did not have sexual contact with anyone other than her boyfriend.  She is very concerned about the fate of her child, who may contract the virus from Anna.

Video version of Anna case (from “AIDS: A Changing Epidemic”, copyright 2002 Discovery Education – used with permission).

Blood samples for ELISA and Western blot:

  • Anna, first trimester
  • Anna, second trimester
  • Anna’s baby, 6 weeks after birth
  • Anna’s boyfriend
  • Positive and negative controls
  1. What is the status of each person tested?  How would you explain these results to Anna?
  2. How would explain the difference between Anna’s first and second trimester results?
  3. What recommendations would you give Anna as she cares for herself and her baby?
  4. How did Anna get infected? How did her boyfriend get infected?
  5. Why did Anna think it was OK to have unprotected sex with her boyfriend?
  6. What does an  indeterminate test mean for the baby? Should the baby be tested again?

Viral load:  After her baby is born, Anna begins taking antiretroviral medications.  A viral load test is performed one, three, and six months after she begins this drug treatment.  After running the PCR analysis on these samples, what would you conclude about the effectiveness of the treatment?

Bioinformatics:  Did Anna’s boyfriend infect her with HIV?  Compare Anna’s and her boyfriend’s HIV sequence with local controls – does tree suggest that their sequences are more similar than random samples?  Can you tell from this who gave it to whom?  Anna’s boyfriend acknowledges that he had another partner.  Does adding this sequence help you determine the sources of Anna’s infection?

Case B.   Katrice grew up in rural Alabama, where there was not much discussion about HIV and AIDS.  At seventeen, she had sex with a popular boy, who she later learned was very promiscuous and a drug user.  She tested HIV positive during a routine blood test several months later.  Katrice went untreated for four years, living in denial about her HIV infection.  She became involved with another man and had a daughter.  She finally sought medical treatment when she thought her daughter might have been exposed to the virus.

Video version of Katrice case Part 1 and Part 2 (from “AIDS: A Changing Epidemic”, copyright 2002 Discovery Education – used with permission).

Blood samples for ELISA and Western blot:

  • Katrice
  • Latranya’s father
  • Latranya, 3 months old
  • Positive and negative controls
  1. What is the status of each person tested?  How would you explain these results to Katrice?
  2. What recommendations would you give Katrice as she cares for herself and her baby?
  3. How did Katrice get infected?
  4. Why did Katrice wait so long to get treatment?
  5. Should Katrice have gotten pregnant? There is no indication that she sought treatment for HIV while pregnant; what was the risk for her baby?
  6. Should Latranya be tested again?

Viral load:  On the advice of her physician, Katrice begins taking antiretroviral medications.  A viral load test is performed one, three, and six months after she begins this drug treatment.  After running the PCR analysis on these samples, what would you conclude about the effectiveness of the treatment?

Bioinformatics:  HIV has been spreading rapidly in the southern U.S.   How does the rate of HIV mutation here compare to the viruses spreading in other parts of the world?  Compare several virus sequences from southern Alabama to sequences isolated in Zimbabwe and Thailand.  Does there appear to be a difference in the rate of mutation, based on the variation between these viruses?  What factors could contribute to different mutation rates?

Case C.  Laverne is a 31-year-old African-American woman who is pregnant and HIV positive.  When she found out she was pregnant, she and her partner, Henry, decided that they could not terminate the pregnancy.  She already has named her baby Marcus, and she is trying to do everything possible to prevent him from becoming infected with the virus.  She is taking medications and eating healthy foods.  She will undergo a Caesarian section, and Marcus will take medications for his first six weeks until he is tested for HIV.

Video version of Laverne case (from “AIDS: A Changing Epidemic”, copyright 2002 Discovery Education – used with permission).

Blood samples for ELISA and Western blot:

  • Laverne
  • Henry
  • Marcus, 6 weeks old
  • Marcus, 3 months old
  • Positive and negative controls
  1. What is the status of each person tested?  How would you explain these results to Laverne?
  2. What recommendations would you give Laverne as she cares for herself and her baby?
  3. How did Laverne get infected?
  4. How did Henry get infected?
  5. Should Laverne have gotten pregnant? What she right to keep the baby rather than terminate the pregnancy? What was the risk to Marcus?
  6. Why did Marcus test positive and then negative?
  7. Should Marcus be tested again?

Viral load:  After her baby is born, Laverne continues taking antiretroviral medications.  A viral load test is performed one, three, and six months after later.  After running the PCR analysis on these samples, what would you conclude about the effectiveness of the treatment?

Bioinformatics:  Although Laverne has been diligent about taking her the drugs and they seemed to be working to reduce her load, her most recent tests show that her viral load is on the rise.  Some strains of HIV isolated in that part of the U.S. have been shown to develop unusually high resistance to the drug treatments.  Compare Laverne’s HIV sequence to several isolated in the region, some of which have shown resistance.  Does she appear to be infected with a drug-resistant virus?  What other options does she have for treatment?

Case D.  Doug grew up in southern California, an all-American boy who surfed and played volleyball.  When he was 20 years old and a junior in college, he revealed that he was gay and moved to San Francisco.  He had a hard time adjusting, and he felt that, in order to fit in, he had to engage in the same risky behaviors as everyone else.  Even though he knew the risks, he had unprotected sex.  Four days before his 24th birthday, he tested positive for HIV.

Video version of Doug case Part 1 and Part 2 (from “AIDS: A Changing Epidemic”, copyright 2002 Discovery Education – used with permission).

Blood samples for ELISA and Western blot:

  • Doug
  • Doug’s partner the night he believes he was infected (partner 1)
  • An earlier partner of Doug’s (partner 2)
  • Positive and negative controls
  1. What is the status of each person tested?  How would you explain these results to Doug?
  2. What recommendations would you give Doug?
  3. How did Doug get infected?
  4. Can you tell from the results which partner infected Doug?
  5. Why was Doug willing to take risks that affected his health?

Viral load:  Doug and his partner begin antiretroviral drug treatments.  A viral load test is performed one, three, and six months after they begin this drug treatment.  After running the PCR analysis on these samples, what would you conclude about the effectiveness of the treatments?

Bioinformatics:  Which of Doug’s partners infected him with HIV?  Compare the three sequences to each other and to random controls in the San Francisco area.  Can you tell from these data who infected whom?  What additional information would you need to make a more definitive determination?

Case E.  Lisa grew up in a wealthy neighborhood, and the kids she grew up with didn’t think they needed to worry about HIV and AIDS.  However, she believes she was infected with while on an island vacation during her college years.  Her father, a physician, helped her find the best medical care, and she immediately began taking medications which seemed to keep her healthy.  A few years later, she married David and wanted to start a family.  They decided to have unprotected sex during times when her viral load was low.  She continued to take medications during her pregnancy, and had C-section deliveries to reduce the risk of passing the virus to her baby.  Lisa and David now have three children.

Video version of Lisa case Part 1 and Part 2 (from “AIDS: A Changing Epidemic”, copyright 2002 Discovery Education – used with permission).

Blood samples for ELISA and Western blot:

  • Lisa
  • David
  • 3-year old child
  • 6 1/2-year old child
  • 9-year old child
  • Positive and negative controls
  1. What is the status of each person tested?  How would you explain these results to Lisa?
  2. What recommendations would you give Lisa as she cares for herself and her family?
  3. How did Lisa get infected?
  4. How do you think David and Lisa felt when he received his ELISA result?
  5. Is it worth the risk to have unprotected sex in order to have children?
  6. What does the indeterminate result mean for their 9-year old child?
  7. Do the negative results for the other children mean that they don’t ever have to worry about becoming HIV positive?

Viral load:  In order to become pregnant, David and Lisa chose to have sexual intercourse during times when her viral load was low.  Analyze the DNA samples provided by PCR.   Based on the PCR results, when do you think they should have tried to conceive?

Bioinformatics:  The boy from whom Lisa thinks she contracted was from New York City, where they had an outbreak of an especially pathogenic HIV strain.  He quickly progressed to AIDS and died shortly after Lisa found out she was infected.   Does it appear that Lisa was also infected with a similar strain?  Compare her sequence to the boy’s and to other high- and low-pathogenic strains.  How does her access to medical affect her situation?  What are the implications for her family?

Case F. Jennifer is a white female who grew up, in her words, “with old-fashioned parents and old-fashioned values.”  She got good grades throughout high school and did not date until her late teens.  But after she graduated from high school and went away to college, she was eager to change her lifestyle.  She started to party a lot and dated several different people.  However, after a drunken sexual encounter with a man she met at a party that left them both feeling horrible the next morning, she decided to take better care of herself and stopped having sex.  Several months later she underwent a series of routing medical tests, including a blood test for HIV.  The HIV test came back positive.  Shocked, Jennifer decided to be tested again at a different clinic.  She contacted two of the boys with whom she had sexual contact (including Jeff, the boy from the party), and suggested they also get tested.

Video version of Jennifer case Part 1 and Part 2 (from “AIDS: A Changing Epidemic”, copyright 2002 Discovery Education – used with permission).

Blood samples for ELISA and Western blot:

  •  Jennifer
  • Jeff
  • Paul
  • Positive and negative controls
  1. What is the HIV status of each person tested?
  2. Do the results provide any information about how Jennifer may have been infected?
  3. What recommendations would you give to Jennifer as she deals with her HIV diagnosis?
  4. How do you think Jennifer’s story would influence other college-age students?

Viral load:  Jennifer begins antiretroviral drug treatments.  A viral load test is performed one, three, and six months after she begins this drug treatment.  After running the PCR analysis on these samples, what would you conclude about the effectiveness of the treatments?

Bioinformatics:  Jennifer’s HIV infection was detected early, and since she started drug treatments right away her virus levels have stayed low.   However, her physician is concerned by recent reports that people who start drug treatment early are more prone to develop drug-resistant viruses.  Compare viruses isolate early in her infection to viruses isolated four years later.  An increase in virus diversity may make drug-resistant mutations more likely.  Can you tell from these results whether Jennifer is more at risk for drug resistance now?

Case G.   In the early 1990’s Steve was an avid long distance runner and the picture of health.  But he suddenly started getting a lot of colds and unusual infections.   Eventually a blood test determined that he was HIV positive.  By the time he was tested he was already exhibiting full-blown AIDS and his prognosis was poor.  He started antiretroviral drug treatments, but they did not seem to help.  When a new class of drugs, protease inhibitors, was approved, Steve changed his medications and immediately began to show improvement.  Amazingly, his immune system seemed to return to normal and he regained much of the weight he lost.  He began running again and finished a marathon.  Two of his running partners were inspired by his situation and decided to get tested.  They both had reason to believe they have been exposed to HIV, but were reluctant to get tested because they were afraid that a positive test would be a “death sentence”. 

Video version of Steve case Part 1 and Part 2 (from “AIDS: A Changing Epidemic”, copyright 2002 Discovery Education – used with permission).

Blood samples for ELISA and Western blot:

  • Steve
  • Runner 1
  • Runner 2
  • Positive and negative controls
  1. What is the HIV status of each person tested?
  2. What recommendations would you give each of them based on their results?

Viral load:  Viral load tests were run three, six, and nine months after Steve started each of his drug treatments. After running the PCR analysis on these samples, what would you conclude about the effectiveness of the treatments?

Bioinformatics:   The drug treatment that seems to be effective for Steve has shown a tendency to develop resistant strains of the virus.  Steve is concerned, since he experienced problems with his original drug regimen and does not want the treatments to fail again.  Compare viruses isolated from Steve with strains that have shown resistance to these drugs.  What can you tell Steve about the chance that he will develop drug resistance?

Case H. Marie thought she had found her perfect match when she started dating Rick, a divorced man who seemed to live a healthy lifestyle and treated her well.  They traveled together frequently and became very close.  But suddenly, Rick’s behavior changed and he became unpredictable,  His mood swings eventually caused them to split up.  Several months later, Marie learned through a mutual friend that Rick was dying of AIDS.  Marie was shocked, and she immediately got tested for HIV.   She also began a program of exercise and nutritional supplements to try to improve her chances of staying healthy.

Video version of Marie (U.S.) case Part 1, Part 2 and Part 3 (from “AIDS: A Changing Epidemic”, copyright 2002 Discovery Education – used with permission).

Blood samples for ELISA and Western blot:

  • Marie
  • Rick
  • Positive and negative controls
  1. What is the HIV status of each person tested?
  2. What recommendations would you give to Marie as she deals with her HIV diagnosis?
  3. What role do you think Marie’s exercise and nutrition program will play in her health?
  4. What would happen if Marie stopped taking the antiviral drugs

Viral load:  Marie begins antiretroviral drug treatments.  A viral load test is performed one, three, and six months after she begins this drug treatment.  After running the PCR analysis on these samples, what would you conclude about the effectiveness of the treatments?

Bioinformatics:  Although the drug treatments have lowered Marie’s viral load, the side effects of the drugs are greatly reducing her quality of life.  Her most recent liver function test show that her current drug regimen is damaging her liver, in spite of her efforts to stay healthy. Her physician recommends an new, experimental drug that blocks virus entry into cells.  This drug has only been tested on certain strains of HIV.  Compare Marie’s sequence to strains that have been shown to respond to this drug treatment.  Would you recommend that she switch to the new drug treatment?

CASES FROM AFRICA

Video introduction to African cases (from “The Faces of AIDS”, Media for Development International – used with permission).

Case I. Nicole is a 25-year old woman living in Cameroon.  She has been diagnosed with AIDS, and is staying in a hospital because she is unable to care for herself.  Her father has refused to help her because he believes she contracted the disease by “sleeping around”.  Her father also forbids her brothers and sisters from seeing her.  She believes she may have been infected by a boy she was seeing for a while, but she has not heard from him in months. 

 Video version of Nicole case (from “The Faces of AIDS”, Media for Development International – used with permission).

Blood samples for ELISA and Western blot:

  • Nicole
  • Nicole’s former boyfriend
  • Positive and negative controls
  1. What is the status of each person tested?
  2. How would you explain these results to Nicole?
  3. What options does Nicole have?
  4. What do you think about Nicole’s father’s decision not to help her?
  5. How important is it to get medications to people like Nicole?
  6. Why did Nicole’s father abandon her?
  7. What resources are available for someone in Nicole’s situation
  8. How did Nicole get infected?

Viral load:  Because her father will not support her financially, she is given only supportive care at the hospital.  As part of a UNAIDS study, blood samples are taken every few months and sent to a hospital in the capital city, Yaounde, so a viral load test can be performed.    Based on the results of testing Nicole’s samples 3, 6, and 12 months after her diagnosis, what is her prognosis?

Bioinformatics:  Nicole’s disease is progressing rapidly, and the physicians in Yaounde suspect that she may be infected with a highly pathogenic strain of the virus that has been detected in other patients tested at the hospital.  Compare Nicole’s virus sequence to highly pathogenic and low-pathogenic strains.  Can you tell from these results if  she was infected with a highly-pathogenic strain?   Does it matter in Nicole’s situation?  What should the scientists involved in the study do with this information?

Case J.  Auxilia, who has just been diagnosed with AIDS, lives with her five children on a small plot of land in Zimbabwe.  Her husband died several years ago.  Auxilia is worried about who will look after her children if she dies.  She knows that there is a lot of stigma associated with AIDS and that people are afraid to interact with her.

Video version of Auxilia case (from “The Faces of AIDS”, Media for Development International – used with permission).

Blood samples for ELISA and Western blot:

  • Auxilia
  • Auxilia’s oldest child
  • Auxilia’s youngest child
  • Positive and negative controls
  1. What is the status of each person tested?  How would you explain these results to Auxilia?
  2. What recommendations would you give Auxilia as she cares for herself and her baby?
  3. What can Auxilia tell people to help them understand that they should not be afraid of her?
  4. How did Auxilia get infected?
  5. How can she get help for her children if she gets sicker?
  6. What treatment options does she have?
  7. What does an indeterminate result mean?

Viral load: Auxilia is selected to enroll in a program that allows her to receive antiretroviral medications.  A viral load test is performed one, three, and six months after she begins this drug treatment.  After running the PCR analysis on these samples, what would you conclude about the effectiveness of the treatment?

Bioinformatics:  Zimbabwe is experiencing an increase in the spread of HIV.  How does the rate of HIV mutation here compare to the viruses spreading in other parts of the world?  Compare several virus sequences from Zimbabwe to sequences isolated in the U.S. and Thailand.  Do you see a difference in the rate of mutation?  What factors could contribute to different mutation rates?

Case K. Marie lives on a small plot of land in Cameroon with her five children.  Her husband died two years ago, and Marie has just been diagnosed with AIDS.  Before she was diagnosed, she did not believe that the disease existed in her country.  Fortunately, Marie’s brother is very supportive and willing to look after her and her children.  He is not afraid of catching the disease from her.

Video version of Marie (African) case (from “The Faces of AIDS”, Media for Development International – used with permission).

Blood samples for ELISA and Western blot:

  • Marie
  • Marie’s brother
  • Marie’s husband
  • Marie’s oldest child
  • Marie’s youngest child
  • Positive and negative controls
  1. What is the status of each person tested?
  2. How would you explain these results to Marie?
  3. What recommendations would you give Marie as she cares for herself and her baby?
  4. What precautions does her brother need to take to keep from getting infected?
  5. How did Marie get infected?
  6. How did Marie’s beliefs about AIDS not being in Cameroon affect her risk of being infected?
  7. What precautions does her brother need to take to keep from being infected?
  8. What resources are available to help Marie care for her children?
  9. Are Marie’s children at risk for HIV?

Viral load:  Marie is selected to enroll in a program that allows her to receive antiretroviral medications.  A viral load test is performed one, three, and six months after she begins this drug treatment.  After running the PCR analysis on these samples, what would you conclude about the effectiveness of the treatment?

Bioinformatics:  Some strains of HIV isolated in that part of the Cameroon have been shown to develop unusually  high resistance to the drug treatments.  Compare Marie’s HIV sequence to several isolated in the region, some of which have shown resistance.  Does she appear to be infected with a drug-resistant virus?  What other options does she have for treatment?

Case L. Tendayi and her husband, Farayi, a married couple in Zimbabwe, learned that they were both HIV positive when their baby died two years ago.  They are supporting each other and planning to stay together; neither blames the other for what happened.  They are focused on finding a way to live with AIDS and to educate others about it.

Video version of Tendayi case (from “The Faces of AIDS”, Media for Development International – used with permission).

Blood samples for ELISA and Western blot:

  • Tendayi
  • Farayi
  • Their 3-year old child
  • Positive and negative controls
  1. What is the status of each person tested?  How would you explain these results to Tendayi?
  2. What recommendations would you give Tendayi and Farayi as they care for themselves and their remaining child?
  3. What can they do to help others understand the disease?
  4. What would happen to them if the medications were no longer available?

Viral load:  Tendayi and Farayi are selected to enroll in a program that allows them to receive antiretroviral medications.  A viral load test is performed one and six months after they begin this drug treatment.  After running the PCR analysis on these samples, what would you conclude about the effectiveness of the treatment?

Bioinformatics:  How did Tendayi and Farayi become infected?  Both have acknowledge having other sexual partners.  Compare each of the virus sequences to viruses isolated from their known partners and from random local controls.  Can you determine how they became infected from these data? Should this information be share with Tendayi and Farayi, even though they have said that they do not want to swell on the past?

Case M.   Safari grew up in a rural village in Kenya and owns a small plot of land.  After he marries, he decides that the land won’t support his family, so he goes to the city to find work.   Eventually, he finds a job and is able to send money home to his wife.  He is only able to visit his home once in a while, and he spends most of his time in the city.  Lonely, he turns to other women for companionship.  His wife, meanwhile, is left to take care of the house and the land by herself.  She becomes pregnant and gives birth to a child, and Safari continues to work in the city.  Safari becomes chronically sick and starts to miss a work frequently.  Safari’s doctor eventually tests him for HIV, and he is positive.  Are his wife and child also infected?

Video version of Safari case Part 1, Part 2, Part 3 and Part 4 (from “AIDS – Life at Stake”, Media for Development International – used with permission).

Blood samples for ELISA and Western blot:

  • Safari
  • Safari’s wife
  • Their baby
  • Positive and negative controls
  1. What is the status of each person tested?  How would you explain these results to Safari and to his wife?
  2. What recommendations would you give to the couple as they care for Safari?
  3. How did Safari get infected?
  4. What does an indeterminate result mean for his wife?
  5. How common is this story?
  6. If Safari had been aware of the risks of HIV infection, would his behavior been different?
  7. Is their baby at risk for HIV infection

Viral load:  Safari is selected to enroll in a program that allows him to receive antiretroviral medications.  A viral load test is performed one and six months after they begin this drug treatment.  After running the PCR analysis on these samples, what would you conclude about the effectiveness of the treatment?

Bioinformatics: Although the drug treatments have lowered Safari’s viral load, the side effects of the drugs are greatly reducing his quality of life and he has still been unable to return to work.  His physician recommends an new, experimental drug that blocks virus entry into cells. The clinical trial will include African as well as U.S. subjects.   This drug has only been tested on certain strains of HIV.  Compare Safari’s sequence to strains that have been shown to respond to this drug treatment.  Would you recommend that he switch to the new drug treatment?