HIV Transmission HASPI Medical Biology Lab 20

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1 HIV Transmission HASPI Medical Biology Lab 20 Background History of HIV/AIDS Acquired Immune Deficiency Syndrome (AIDS) was first seen in 1981 when large numbers of people with two rare diseases surfaced: Kaposi's Sarcoma, a form of skin cancer, and Pneumocystis Carinii Pneumonia, a form of pneumonia. The cases were primarily seen in New York and California. In 1984, Dr. Robert Gallo identified a retrovirus present in all AIDS patients. In 1986, the retrovirus that causes AIDS received its final name Human Immunodeficiency Virus (HIV). Name: Period: Date: pics/adult hiv prevalence3.gif In 1987, the Federal Drug Administration approved Zidovudine (AZT) as the first antiretroviral drug to be used as a treatment for AIDS. Additional effective drugs became available as of By December 1990, over 307,000 AIDS cases had been officially reported to World Health Organization, but the actual number was estimated to be closer to a million. By 1994, AIDS had become the leading cause of death amongst Americans between the ages of 25 and 44. In 1999, the first human trial of an AIDS vaccine was started. Today, 36.1 million people are estimated to be living with HIV/AIDS. Of these, 34.7 million are adults million are women, and 1.4 million are children under 15 (AVERT 2010). Symptoms An individual may become infected with HIV, and have no symptoms from a few months to more than 10 years. During this time, the virus is invading and infecting T cells throughout the body. HIV specifically infects a type of T cell called CD4+ T cells. These T cells are responsible for helping the body respond to an infection. Eventually the HIV infection destroys the number of T cells in the body, which prevents the immune system from functioning. The weakened immune system reaches a point where it is no longer able to recognize or combat an infection. WCQDM0/s320/572px-Symptoms_of_acute_HIV_infection.svg.png The Center for Disease Control (CDC) currently defines AIDS as a T cell count that is less than 200/cells per cubic millimeter of blood. They may contract pneumonia, tuberculosis, brain infections, cancer, and/or other illnesses. Victims normally die a year or two after developing AIDS. 279

2 HIV Structure and Life Cycle A retrovirus is a virus with RNA as its genetic material. Retroviruses are able to insert their genetic material into a host cell. Once a retrovirus inserts its genetic material, it is able to make it part of the host s DNA permanently, and can only be destroyed by killing the entire host cell. The process of HIV invasion into a CD4+ T cell is outlined in the diagram below

3 How HIV/AIDS Infects HIV is typically contracted from one of the following interactions: 1. Sharing hypodermic needles, such as when injecting illegal drugs 2. Having sexual contact, such as oral, vaginal, or anal sex 3. Being born to an HIV-infected mother 4. Getting HIV-infected blood into an open wound The HIV virus cannot survive outside of the body and is destroyed by simple cleaning methods. HIV/AIDS Diagnosis and Treatment HIV is diagnosed by the detection of antibodies for HIV in the blood or saliva. AIDS is diagnosed by counting the number of CD4+ T Cells, and anything less than 200 would identify the victim as having AIDS. The treatment of HIV and AIDS has advanced remarkably over the last few years, especially in industrialized, wealthy nations. However, no cure has been found. There are many Antiretroviral Therapy (ART) drugs, and it is common for a patient to be given multiple ART drugs at once. A combination of 3 or more ART drugs is called a Highly Active Antiretroviral Therapy (HAART). Materials Numbered plastic vial w/cap Plastic pipette HIV test solution Procedure 1. Find a partner, and ask them the questions provided in Data Table Record their name, vial number, and answer to each question in Data Table 1 in the Analysis Section. 3. After you exchange and record the information, open your plastic vial and fill your plastic pipette with approximately 1-2 ml of fluid from the vial. Your partner will do the same. 4. Empty the contents of your plastic pipette into your partner s vial and replace the cap. 5. When your teacher instructs you, find a new partner and repeat steps This activity is meant to simulate the unsafe sharing of fluids between 5 partners. Once you have exchanged information and fluids with 5 partners, the next step is to choose whether you should get tested for HIV or not. 7. If you choose to be tested, your teacher will make the HIV test solution available for you. Place 1-2 drops of the HIV test solution into your plastic vial, replace the cap, and shake to mix. 8. If there is ANY pink coloration to the liquid in your vial you have been infected with HIV. To check for even the faintest shade of pink, place your vial against a white sheet of paper. 9. Check in with all of your partners to determine whether they decided to be tested, and if they did, whether they tested positive or negative for HIV. 10. Determine which round (1-5) you were infected and report that number for the classroom tally before completing Data Table

4 Analysis Your vial #: Classmate s Name Vial # What career are you interested in? Why? Data Table 1 On a scale of 1-10, 1 being least serious and 10 most, how big of an issue do you think HIV is in the U.S.? Why? HIV tested or not? If tested, are they HIV+ or HIV-? *Complete the last two columns of data table 1 following all partner fluid exchange, and the HIV Test. Classroom Total Number of persons infected? Total persons in room? Data Table 2 Hypothesized number of infections? 1 *Complete data table 2 based on the collected class data. Starting Round Round 1 Round 2 Round 3 Round 4 Round 5 1 Analysis Questions on a separate sheet of paper complete the following: 1. Did you decide to have the HIV test? Why or why not? 2. If yes, who were you infected by? Who did you infect? 3. Did any of those you exchanged fluids with test HIV positive? If yes, would you reconsider testing? Why or why not? 4. Did every person in the room become infected? If we continued further with this activity, would everyone eventually get HIV? Explain. 5. During the spread of a real viral infection, not everyone in the community will get the disease no matter how long it lasts. What might be some explanations for this? Include the word immunity in your answer. 282

5 Review Questions - on a separate sheet of paper complete the following 1. How was HIV discovered and by who? What are some of the treatment options available for those individuals that are HIV positive? 2. How many people are currently infected with HIV? Which continent has the highest percentage of people infected? 3. Examine Image A below. After identifying the continent with the highest HIV positive population, what issue do you find with Image A below? 4. Explain the different between HIV and AIDS. How can HIV lead to AIDS? 5. Discuss at least two ways HIV/AIDS can be spread. 6. List 3 symptoms that may develop in someone infected with HIV. 7. What does a person with HIV look like worldwide? Can you recognize someone with this virus? 8. How does the name AIDS describe the action of the disease? 9. Why do people who have unsafe sex or inject drugs have a higher risk of acquiring HIV? 10. Complete the following chart summarizing the function of the major cells of the immune system. Hypothesize what might happen if each one of these cell types was not able to function correctly. Immune System Cell Function What would happen if this cell was not functioning correctly? B lymphocytes Helper (CD4+) T lymphocytes Cytotoxic (CD8+) T lymphocytes Granulocytes Macrophages Dendritic cells 11. What happens to CD4+ T lymphocytes infected by HIV? 12. Describe the steps by which HIV infects CD4+ T lymphocytes. Feel free to draw/label. 13. Why might a person think they may not be infected with HIV? 14. How does the HIV vaccination work to enhance the body s immune system? 15. CONCLUSION: In 1-2 paragraphs summarize the procedure and results of this lab. Image A Coverage % 50-69% 26-49% 10-25% Less than 10% 283

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