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39 Cards in this Set
- Front
- Back
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What percent of HIV is reported?
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40%
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Which strain of HIV is more common?
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HIV-1 (causing AIDS epidemic)
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Where is HIV 2 found?
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West Africa
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What is a lentivirus?
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A virus that causes a long illness (like HIV)
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What is the theory of HIV 1 development?
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SIV to HIV2 to HIV1
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When was HIV recognized?
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1981 (disease present in 1950s in Africa, 1970s USA)
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What are the most common subtypes of HIV1?
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HIV-1 subtype B: Europe/Americas
HIV-1 subtype C: Subsaharan africa |
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The most common HIV subtype?
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HIV-1 C: In subsaharan africa
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What are the two genetic subgroups of HIV1?
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HIV-1 M (main)
HIV-1 O (outlyer) |
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What were the indicators of HIV in 1980s?
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Kaposi's sarcoma and PCP pneumonia in young men
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How does HIV enter cells?
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CD4+ T-lyphocytes have surface receptors that can attach to HIV and promote cell entry
Also infect Langerhans cells (antigen presenting cells) in mucosal surfaces Also infect lyphoid tissues -- follicular dendritic cells |
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Describe the HIV structure
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Core with an envelope and glycoproteins on surface
(including GP 120 -- extracellular and GP 41 -- intracellular) |
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How does HIV get into CD4 T cells?
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Attaches to GP120 receptor, facilitated by CXCR4 and CCR5 coreceptors
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Describe stages of HIV infection
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1. Acute infection (acute retroviral sydrome) -- flu-like, mono-like, rash
2. Strong cell-mediated and humoral anti-HIV immune defense (few weeks in) 3. Clinical latency 1-15 years 4. Loss of CD4 cells and immune response 5. AIDS |
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How to diagnose HIV?
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In early HIV, PCR for viral nucleaic acid (the p24 antigen)
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Why are some people long-term non-progressors in HIV?
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May have coreceptor mutations that inhibits HIV entry into CD4 cells
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What is the clinical latency phase of HIV?
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No sx
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What is the window period in HIV?
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The time where there are no detectable antibodies
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How is AIDS defined
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CD4 < 200
OR Presence opportunistic infection plus HIV+ |
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What is the Bangui definintion?
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WHO's first clinical case definition of HIV when testing not available...criticized and revised 1994
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What is a normal CD4 count?
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1000
>500 - no sig immunosuppression <200 AIDS |
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How do you test for HIV?
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1 screening test and 2 confirmatory tests
Screening: high sensitivity Confirmatory: high specificity |
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How long can maternal antibodies persist for HIV?
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18 months
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How diagnose HIV in a newborn?
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Can compare titre IgM antibody, look for a 4 fold rise
PCR for p24 antigen is specific |
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What percent of HIV+ in developing world DONT know their status?
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60%
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How did HIV rates drop from 39 million to 33 million from 2007-2009?
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Change in way rates calculated
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Prevalence of HIV in 2009?
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33.4 million
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Incidence of HIV in 2009?
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2.7 million
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Deaths from HIV in 2009?
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2 million
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What percentage of infected people with HIV get care?
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42%
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What are the HIV barrier methods?
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Condoms
Vaginal microbicides (decreased by 39%) |
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How does circumcision impact HIV?
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Decreases transmission
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What is PEPFAR?
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President's Emergency Plan for AIDS Relief (2003)
$15 billion to 15 countries |
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What is the risk of vertical transmission of HIV?
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18-30%
THIS IS THE MOST IMPORTANT CONTROL PROGRAM |
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What factors increase MTCT (mother to child transfer) of HIV?
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High maternal HIV1 RNA levels
Advanced maternal disease Low maternal CDF count Acute maternal HIV infection during pregnancy |
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Vertical transmission antiviral recommendations?
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AZT to mother weeks 14-34, labour and delivery
Baby first 6 weeks of life (<1% transmission!) (Or single dose nevirapine during delivery and to newborn within 72 hours...fear resistance...better than AZT) |
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What is the benefit of treating other STDs?
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Treat other STDs, and HIV transmission drops by 42%
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What is the role of other STDs in HIV transmission>?
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Increases acquisition AND transmission of HIV
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What is the leading cause of death in HIV?
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TB (1 in 3)
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