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group_2_presentation_2_-_human_immunodeficiency_virus_acquired_immunodeficiency_syndrome_hiv_aids [2016/11/03 20:16]
khanba3
group_2_presentation_2_-_human_immunodeficiency_virus_acquired_immunodeficiency_syndrome_hiv_aids [2018/01/25 15:18] (current)
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 ===== Introduction ===== ===== Introduction =====
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 In 1981, AIDS first broke out in the US amongst gay men in New York and San Francisco. They were initially classified as having a mysterious pneumonia-like disease that presented with a rare from of skin cancer, thrush, and other characteristic symptoms. Since this was highly prevalent in gay men, the name for this disease was called GRID, or Gay-related Immune Deficiency (Holland, 2013). In 1981, AIDS first broke out in the US amongst gay men in New York and San Francisco. They were initially classified as having a mysterious pneumonia-like disease that presented with a rare from of skin cancer, thrush, and other characteristic symptoms. Since this was highly prevalent in gay men, the name for this disease was called GRID, or Gay-related Immune Deficiency (Holland, 2013).
  
-In a matter of 2 years, AIDS became a pandemic. This was largely due to the fact that funding ​regarding research pertaining ​to gay men, a group that was highly discriminated against ​at the time, was difficult to attain. This halt in research gave the virus time to spread across the world, such as Africa, Europe, and Asia. More importantly,​ the disease was found to be prevalent in both sexes, which contradicted the initial theory that gay interactions lead to the disease, and so it was re-labelled to AIDS. Unfortunately,​ AIDS became the leading cause of death in people aged 25-44, however, this statistic accelerated research surrounding the disease (Holland, 2013)+In a matter of 2 years, AIDS became a pandemic. This was largely due to the fact that research ​funding ​was compromised due to the prejudice surrounding ​gay men at the time. This halt in research gave the virus time to spread across the world, such as Africa, Europe, and Asia. More importantly,​ the disease was found to be prevalent in both sexes, which contradicted the initial theory that gay interactions lead to the disease, and so it was re-labelled to AIDS. Unfortunately,​ AIDS became the leading cause of death in people aged 25-44, however, this statistic accelerated research surrounding the disease (Holland, 2013)
  
-Since finding a cure to AIDS was incredibly difficult, the goal was shifted to AIDS prevention. In 1984, the first method of prevention was established based on the finding that AIDS was transmitted through mucosal ​membranes, and blood transfusions. ​This included safe sex (especially the use of condoms), testing blood in blood banks, and giving clean needles to drug users (“A Timeline of HIV/​AIDS”,​ n.d). +Since finding a cure to AIDS was incredibly difficult, the goal was shifted to AIDS prevention. In 1984, the first method of prevention was established based on the finding that AIDS was primarily ​transmitted through ​sexual intercourse associated with mucosal ​membrane abrasions, and blood transfusions. ​Thus, prevention methods ​included ​the promotion of safe sex (especially ​through ​the use of condoms), testing blood in blood banks, and giving clean needles to drug users (“A Timeline of HIV/​AIDS”,​ n.d). 
  
-By the late 1980s, HIV was officially labelled as a retrovirus that causes AIDS. After this, anti-retroviral drugs were created and administered. One of these drugs was called zidovudine, or AZT. This prevented AIDS progression,​ rather than providing a cure (Holland, 2013). ​+By the late 1980s, HIV was officially labelled as a retrovirus that causes AIDS. As research surrounding the properties of retrovirus continuedthe first anti-retroviral drugs were created and administered. One of these drugs was called zidovudine, or AZT. This prevented AIDS progression,​ rather than providing a cure (Holland, 2013). ​
  
 However, despite advances in AIDS therapy, the majority of people suffering from AIDS did not have proper health care or access to treatment. The region with the highest prevalence of AIDS was in Sub-Saharan Africa. By 1999, around 33 million people, including women, children and men, were living with HIV. Since the first reported case of AIDS in the 1980s, around 14 million people had died ("​Global HIV/AIDS Overview",​ 2016). However, despite advances in AIDS therapy, the majority of people suffering from AIDS did not have proper health care or access to treatment. The region with the highest prevalence of AIDS was in Sub-Saharan Africa. By 1999, around 33 million people, including women, children and men, were living with HIV. Since the first reported case of AIDS in the 1980s, around 14 million people had died ("​Global HIV/AIDS Overview",​ 2016).
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-National surveillance systems in Canada and the United states have been used to observe the trends in AIDS and HIV.  In 2005 AIDS diagnosis rates in the United states were substantially higher in blacks, followed by hispanics and then caucasians. In Canada, the AID diagnosis were higher for aboriginal peoples, then blacks, and substantially lower for caucasians. ​(Figure 1) In both countries the trend was seen that HIV diagnosis increased for men who were having sex with men, and in general men were diagnosed at substantially higher rates than women. ​(insert figure 2 ) The age group with the highest rate of diagnosis was 30-39. ​(insert figure 3)  +National surveillance systems in Canada and the United states have been used to observe the trends in AIDS and HIV.  In 2005 AIDS diagnosis rates in the United states were substantially higher in blacks, followed by hispanics and then caucasians. In Canada, the AID diagnosis were higher for aboriginal peoples, then blacks, and substantially lower for caucasians. In both countries the trend was seen that HIV diagnosis increased for men who were having sex with men, and in general men were diagnosed at substantially higher rates than women. The age group with the highest rate of diagnosis was 30-39. ​In Canada, the rates peaked in 1984-1985, which is associated largely with the male homosexual population increase. After 1985, a steady decrease ​is seen until the early 1990s which was followed by another peak during 1996 and 1997. This peak can be linked back to the high infection rates among the injection drug users population. Incident infections may have increased somewhat since the late 1990s, but there is a great deal of uncertainty associated with recent incidence estimates and if present, this increase is much less than that seen in the early 1980sAt any rate, it can be stated with more certainty that diagnosis rates have not decreased in recent years. There is a need for prevention efforts in order to reduce the diagnosis rates, especially ​in ethnic minorities, as well as men who have sex with men. (Hall, 2009) 
- +
-It is seen that 54 % of United State diagnosis ​and 64% of Canadian diagnosis were found late in the disease process ​Overall ​diagnosis rates have been stable and not decreased in recent years. There is a need for prevention efforts in order to reduce the diagnosis rates in ethnic minorities, as well as men who have sex with men. +
  
 {{:​pres_2_picture.png|}} {{:​pres_2_picture.png|}}
  
-//Figure 3: Rates of HIV diagnosis by age, 33 US states (A) and Canada//+//Figure 3: Rates of HIV diagnosis by age, 33 US states (A) and Canada. Retrieved from:​http://​dx.doi.org/​10.1097/​qai.0b013e3181a2639e 
 + //
  
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 {{:​hiv_structure.jpg|}} {{:​hiv_structure.jpg|}}
 +
 //Figure 4: Structure of viral HIV. Retrieved from: https://​learner.org/​courses/​biology/​units/​hiv/​index.html // //Figure 4: Structure of viral HIV. Retrieved from: https://​learner.org/​courses/​biology/​units/​hiv/​index.html //
  
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 +
 +===== Prognosis of HIV =====
 +
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 +
 +The timeline of an HIV infection begins at the acute stage, specifically known as “acute retroviral syndrome”,​ where the individual is first infected with the virus. They show no immediate symptoms, and two to four weeks later likely experience flu-like symptoms, of which include a fever, rash, muscle pain, and swollen glands. It is at this stage that the individual is at most risk of transmitting the virus to other people, as the viral load in their blood is at the highest level. ​
 +
 +After the appearance of the flu-like symptoms, the viral particles then begin to reproduce at a very slow pace, and no longer aggravate any symptoms within the individual. This is the longest stage of the HIV infection, as it lasts an average of ten years. Certain factors do delay or accelerate the onset of AIDS, such as nutrition, genetic background, antiretroviral therapy (which will delay the onset of AIDS), and co-infection with other viruses (which will accelerate the onset of AIDS)
 +
 +The final stage of the HIV infection is the onset of AIDS. As HIV is a virus that targets your CD4+ T cells, AIDS is diagnosed when the CD4+ T cell levels falls below 200 cells/mm3 of blood. This exposes the immune system, allowing for opportunistic infections to occur (“Stages of HIV infection”,​ 2015). The most common and severe infection to occur is pneumocystis pneumonia (“Fungal Diseases”,​ 2014) a fungal infection that causes fever, ​ shortness of breath, fatigue, and a dry cough. Antibiotic treatment is used, as without proper treatment the mortality rate is closer to 100% (“Stages of HIV infection, 2015). Figure 6 (below) shows the general progression form HIV to AIDS, noting the gradual decline of CD4+ T cells, which is correlated to the increase in viral load at the onset of AIDS.
 +
 +</​style>​
 +
 +{{:​small_hiv_stages_graph.jpg|}}
 +
 +//Figure 6: Progression of an HIV infection. Retrieved from http://​annals.org/​aim/​article/​709558/​immunopathogenic-mechanisms-hiv-infection //
 +
 +===== Screening and Diagnosis =====
 +
 +<style justify>
 +
 +There is a wide range of tests done to screen someone for the presence of an HIV infection. The most commonly used procedure is an Enzyme-Linked Immunosorbent Assays (ELISA for short), which tests for antibodies present in the patients’ blood or oral fluid. First, a multi-well plate is filled with antigens, and then these wells are filled with the patients’ fluid sample. The wells are then washed out to remove any unbound antibodies, and an enzyme conjugate (specifically an animal immunoglobulin with an attached enzyme) is added, which will then bind to the specific antibody. The plate is washed out once more, and substrates that interact with the enzyme to produce colour are added to the wells. A coloured plate will therefore indicate an HIV positive test (“HIV Antibody Assays”, 2006). A person infected with HIV only produces a measurable amount of HIV antibodies three to twelve weeks post infection, so it is recommended that a person is retested 3 months after possible exposure, as screening during this “window period” will lead to a false negative (“HIV/​AIDS Testing”, 2016). ​
 +
 +A fourth generation assay, used by all laboratories across Canada, detects both HIV antibodies and the p24 antigen, a viral protein that composes the majority of the viral core (Wilton, 2015). ​ It takes approximately two to six weeks for an individual to produce enough antibodies and antigens for a successful reading, therefore it is suggested that a re-test is done if the individual is tested during this period of time and receives a negative result (“HIV/​AIDS Testing”, 2016). ​
 +Two home tests are available on the market, the Home Access HIV-1 Test System and the OraQuick In-Home HIV test. The former test involves the individual pricking their finger to collect a blood sample and sending the sample to a laboratory. Their results are then processed as early as the following business day. The latter test is a home swab kit for oral fluid sample, and provides results within twenty minutes. A positive test will require a follow-up test at a clinic. Both tests detect HIV antibodies in the body fluids (“HIV Test Types”, 2015).
 +
 +</​style>​
 +
 +===== Transmission =====
 +
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 +
 +The HIV virus is only transmittable through bodily fluids, specifically blood, semen, pre-seminal fluids, breast milk, and rectal and vaginal fluids. It is only spread through contact with mucosal membranes (via anal and vaginal membranes during sex), damaged tissues, and direct injection of the virus into the bloodstream (through sharing needles). It can also be spread from mother to child over the course of a pregnancy, childbirth, and breastfeeding (“HIV Prevention”,​ 2016).
 +
 +</​style>​
 +
 +
 +{{:​picture1.jpg|}}
 +
 +
 +//Figure 7: Modes of HIV transmission from human-to-human. Retrieved from: http://​www.avert.org/​hiv-transmission-prevention/​how-you-get-hiv
 +//
  
 ===== Treatments ===== ===== Treatments =====
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-Currently, there is no cure for HIV/Aids, but medications are effective in fighting HIV and its complications. Most of the treatments are designed to reduce HIV in your body, keep your immune system as healthy as possible and decrease the complications you may develop. Several medications used for treatment have shown to slow down the growth of the virus or stop it from making copies of itself. Although these drugs don’t eliminate the virus completely from the body, they keep the amount of virus in the blow low. The amount of virus in the blood is called viral load and it can be measured by a test.+Currently, there is no cure for HIV/Aids, but medications are effective in fighting HIV and its complications. Most of the treatments are designed to reduce HIV in your body, keep your immune system as healthy as possible and decrease the complications you may develop. Several medications used for treatment have shown to slow down the growth of the virus or stop it from making copies of itself. Although these drugs don’t eliminate the virus completely from the body, they keep the amount of virus in the blow low. The amount of virus in the blood is called viral load and it can be measured by a test (Nordqvist, 2016).
  
  
-There are several types of anti-HIV drugs and each type attacks the virus in its own way. Most people who are getting treated for HIV take 3 or more drugs. This is called combination therapy or “the cocktail”. Combination therapy is the most effective treatment for HIV (Robinson, 2016). HIV medicines have become much easier to take in recent years. Some of the newer drug combinations package three separate medicines into only one pill take once a day with minimal side effects. Most of the medications taken are tolerable and effective and let HIV-positive people live long and healthy lives although this is not the same case for every HIV patient it might be difficult for certain people to take the medication or cause some serious side effects (Robinson, 2016). It is possible for some of these drugs taken to become less effective overtime or stop working. Once the patient has taken the medication, they must discuss with their health care provider to monitor how well the medications are working and to find solutions for side effects.+There are several types of anti-HIV drugs and each type attacks the virus in its own way. Most people who are getting treated for HIV take 3 or more drugs. This is called combination therapy or “the cocktail”. Combination therapy is the most effective treatment for HIV (Robinson, 2016). HIV medicines have become much easier to take in recent years. Some of the newer drug combinations package three separate medicines into only one pill take once a day with minimal side effects. Most of the medications taken are tolerable and effective and let HIV-positive people live long and healthy lives although this is not the same case for every HIV patient it might be difficult for certain people to take the medication or cause some serious side effects (Robinson, 2016). It is possible for some of these drugs taken to become less effective overtime or stop working. Once the patient has taken the medication, they must discuss with their health care provider to monitor how well the medications are working and to find solutions for side effects ​(Nordqvist, 2016).
  
 **Earlier HIV Antiretroviral treatment** **Earlier HIV Antiretroviral treatment**
  
-This treatment improves quality of life, extends life expectancy and reduces the risk of transmission according to the World Health Organization’s guidelines issued in 2013 (Nordqvist, 2016). When an HIV-positive adults CD4 cell count is 500 cells/​mm3 ​ or lower they should start treatment immediately.+This treatment improves quality of life, extends life expectancy and reduces the risk of transmission according to the World Health Organization’s guidelines issued in 2013. When an HIV-positive adults CD4 cell count is 500 cells/​mm3 ​ or lower they should start treatment immediately ​(Nordqvist, 2016).
  
 {{:​hiv-drug-classes.svg.png|}} {{:​hiv-drug-classes.svg.png|}}
  
-Figure ​6: HIV Antiretroviral Treatment  +//Figure ​8: HIV Antiretroviral Treatment  
-https://​upload.wikimedia.org/​wikipedia/​commons/​thumb/​d/​d5/​HIV-drug-classes.svg/​450px-HIV-drug-classes.svg.png+Retrieved from: https://​upload.wikimedia.org/​wikipedia/​commons/​thumb/​d/​d5/​HIV-drug-classes.svg/​450px-HIV-drug-classes.svg.png ​//
  
 **Emergency HIV pills** **Emergency HIV pills**
  
-If an individual believes that they have been exposed to the virus within the last 3 days (72 hours) anti-HIV medication called PEP (post-exposure prophylaxis) may stop the infection (Nordqvist, 2016). This treatment is very useful as it should be taken as soon as possible after contact with the virus. PEP is a very demanding treatment lasting about four weeks and it also includes side effects such as diarrhea, nausea, weakness and fatigue.+If an individual believes that they have been exposed to the virus within the last 3 days (72 hours) anti-HIV medication called PEP (post-exposure prophylaxis) may stop the infection (Nordqvist, 2016). This treatment is very useful as it should be taken as soon as possible after contact with the virus. PEP is a very demanding treatment lasting about four weeks and it also includes side effects such as diarrhea, nausea, weakness and fatigue ​(Robinson, 2016).
  
  
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 **Nucleoside Reverse Transcriptase Inhibitors (NRTI)** **Nucleoside Reverse Transcriptase Inhibitors (NRTI)**
  
-·         These drugs interrupt the virus from duplicating,​ which may slow the spread of HIV in the body. These include:+·         These drugs interrupt the virus from duplicating,​ which may slow the spread of HIV in the body. They do this by binding to the reverse transcriptase enzyme leading to its degradation. These include:
 ·         ​Abacavir ·         ​Abacavir
 ·         ​Didanosine ·         ​Didanosine
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-Combinations of these NRTIs make it possible to take lower doses and maintain effectiveness.+Combinations of these NRTIs make it possible to take lower doses and maintain effectiveness ​(Nordqvist, 2016).
  
 </​style>​ </​style>​
  
-===== Other HIV Medications ===== 
- 
-<style justify> 
  
 **Fusion Inhibitors** **Fusion Inhibitors**
  
-Fusion inhibitors are new class of drugs that act against HIV by preventing the virus from fusing with the inside a cell, preventing it from replicating (Nordqvist, 2016). The group of drugs includes Enfuvirtide,​ also known as Fuzeon or T-20.+Fusion inhibitors are new class of drugs that act against HIV by preventing the virus from fusing with the inside a cell, preventing it from replicating (Nordqvist, 2016). The group of drugs includes Enfuvirtide,​ also known as Fuzeon or T-20 (Nordqvist, 2016).
  
  
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 ·         ​Delvaridine ·         ​Delvaridine
 ·         ​Efavirenz ·         ​Efavirenz
-·         ​Nevirapine+·         ​Nevirapine ​(Robinson, 2016). 
 + 
 + 
 +===== Current Research ===== 
 + 
 +<style justify>​ 
 + 
 +As of November 2nd 2016, the first HIV Vaccine Trial has been initiated in South Africa, which has 7 million HIV-infected individuals,​ or one-fifth of the world HIV-positive population. Approximately 5400 men and women are enrolled in Phase III clinical trials of the HVTN (HIV Vaccine Trials Network) 702 vaccine (Surugue, 2016). The vaccine regimen actually consists of two different vaccines: the first is a canarypox-based vaccine, and the second is a bivalent GP120 subunit with an adjuvant to elicit an immune response. The canarypox-based vaccine is viral vaccine that elicits a cytotoxic T cell response towards HIV-infected cells. The bivalent GP120 vaccine with and adjuvant also helps boost the host's immune system by developing antibodies to recognize and remove viral particles if they enter the body. The type of GP120 subunit used is known to be associated with the strain of HIV that is the most prevalent in South Africa ("​Large Scale HIV Vaccine Trial",​ 2016). This provides the population with pre-exposure prophylaxis to prevent the the incidence and spread of HIV. The trial will last from November 2016 to December 2020 (Surugue, 2016). ​
  
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 +
 +===== References =====
 +
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 +
 +  * A Timeline of HIV/AIDS. (n.d.). Retrieved October 17, 2016, from https://​www.aids.gov/​hiv-aids-basics/​hiv-aids-101/​aids-timeline/​index.html
 +  * AIDS.gov. (2015). HIV Test Types. Retrieved from https://​www.aids.gov/​hiv-aids-basics/​prevention/​hiv-testing/​hiv-test-types/​AIDS.gov. (2015). HIV Test Types. Retrieved from https://​www.aids.gov/​hiv-aids-basics/​prevention/​hiv-testing/​hiv-test-types/​
 +  * AIDS.gov. (2015). Stages of HIV Infection. Retrieved from https://​www.aids.gov/​hiv-aids-basics/​just-diagnosed-with-hiv-aids/​hiv-in-your-body/​stages-of-hiv/​
 +
 +  * AIDSInfo. (2016). HIV Prevention. Retrieved from https://​aidsinfo.nih.gov/​education-materials/​fact-sheets/​20/​48/​the-basics-of-hiv-prevention
 +  * AidsInfo. N.d. HIV Life Cycle. Retrieved from: https://​aidsinfo.nih.gov/​education-materials/​fact-sheets/​19/​45/​hiv-aids--the-basics
 +  * Berger, E., Garrett, L., MacGregor, R. R., Vonmuller, E., Weiner, D. 2016. HIV and AIDS. Annenberg Learner. 91-106.
 +
 +  * Centers for Disease Control and Prevention. (2016). HIV/AIDS Testing. Retrieved from http://​www.cdc.gov/​hiv/​basics/​testing.html
 +
 +  * Global HIV/AIDS Overview. (2016, September 28). Retrieved October 20, 2016, from https://​www.aids.gov/​federal-resources/​around-the-world/​global-aids-overview/​index.html
 +
 +  * Hall, H., Geduld, J., Boulos, D., Rhodes, P., An, Q., & Mastro, T. et al. (2009). Epidemiology of HIV in the United States and Canada: Current Status and Ongoing Challenges. JAIDS Journal Of Acquired Immune Deficiency Syndromes, 51(Supplement 1), S13-S20. http://​dx.doi.org/​10.1097/​qai.0b013e3181a2639e
 +
 +  * Holland, K., & Krucik, G. (2013, July 12). The History of HIV. Retrieved October 17, 2016, from http://​www.healthline.com/​health/​hiv-aids/​history#​EarliestCase1
 +  * Large-Scale HIV Vaccine Trial to Launch in South Africa | NIH: National Institute of Allergy and Infectious Diseases. (2016, May 18). Retrieved November 04, 2016, from https://​www.niaid.nih.gov/​news-events/​large-scale-hiv-vaccine-trial-launch-south-africa
 +
 +
 +
 +  * Nordqvist, C. (2016, May 11). "​HIV/​AIDS:​ Causes, Symptoms and Treatments."​ Medical News Today. Retrieved 26 October 2016, from http://​www.medicalnewstoday.com/​articles/​17131.php.
 +
 +  * Robinson, J. (2016). Understanding Treatment of AIDS/HIV. WebMD. Retrieved 26 October 2016, from http://​www.webmd.com/​hiv-aids/​guide/​understanding-aids-hiv-treatment?​page=3
 +  * Sharp, P. M., & Hahn, B. H. (2011). Origins of HIV and the AIDS pandemic. Cold Spring Harbor perspectives in medicine,​ 1(1),​ a006841.
 +
 +  * Simon, V., Ho, D. D., Karim, Q. A. 2006. HIV/AIDS Epidemiology,​ pathogenesis,​ prevention and treatment. The Lancet, 368: 489-504.
 +  *   ​Surugue,​ L. (2016, November 2). First large-scale HIV vaccine trial in seven years to start in South Africa. International Business Times. Retrieved November 2, 2016, from http://​www.ibtimes.co.uk/​first-large-scale-hiv-vaccine-clinical-trial-seven-years-start-south-africa-1589468
 +
 +
 +  * University of California San Francisco. (2006). HIV Antibody Assays. Retrieved from http://​hivinsite.ucsf.edu/​InSite.jsp?​page=kb-02-02-01
 +
 +
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