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15 Cards in this Set
- Front
- Back
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HIV-1 vs HIV-2:
Virulence Geographic Origin |
HIV-1:
Most common human retrovirus! More virulent Epidmeic first started in Central Africa w/subsequent global spread HIV-2: Not as virulent, much less prevalent, less infection by same routes Most HIV-2 in WEST Africa |
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HLTV-I vs HLTV-II:
Disease Progression Interactions with HIV |
HLTV-1: rarely cause spastic paraparesis, leukemia/lymphoma; latent for decades
HIV more virulent in pts with HTLV-1 HLTV-2: clinical importance unclear |
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What factors affect HIV infectiousness/susceptibility?
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Concomitant STD (increases HIV infectiousness and cells that can transit/become be infected)
Acute or Advanced HIV infection: more virus-->more transmission Genital Tract Inflammation or cervical ectopy Type of HIV strains (based on clade) |
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What populations are most affected by HIV?
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Gay/bisexual men have 1/2 of all US infections
IDU's around 25% of new infections |
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What cells can HIV infect?
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Primarily CD4's, mac/smonocytes
Also: neuroglia, GI mucosa, DC's, B cells |
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How does HIV result in immunosuppression?
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HIV spreads early to BM and lymphoid tissue, more than 10 billion virions produced DAILY
T cells live less than 2 days post-infection AIDS immunosuppression due to progressive decrease in immune system's ability to keep up with replicative ability of HIV |
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What glycoproteins are expressed on the HIV envelope?
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gp160, gp41 (coded by end)
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Function of nef, rev?
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Regulatory genes that accelerate HIV's ability to replicate and be cytopathologic
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Briefly describe the infective cycle of HIV.
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1) Approach binding site
2) Attach to CD4+ coreceptor 3) Fuse to cell membrane 4) UNCOAT virus in cell cytoplasm 5) Become DNA provirus after reverse transcripatase 6) Integrate in target cell nucleus 7) New viral RNA made 8) Assembly into new virions 9) Virions bud out, infect new cells |
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How is HIV infection and therapy monitored?
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Via CD4 lymphopenia and function
(results in decreased hypersenstivity, i.e. TB anergy; dec'd NKC activity, dec'd ability to assit B lymphocyte fn) ALSO VIA PCD, Branch Chain DNA test (bDNA), Nucleic Acid Sequence Based Analysis (NASBA) to detect low levels of viral DNA or RNA--tests nucleic acid-plasma viremia (AKA PLASMA VIRAL LOAD TEST) |
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Diagnostic criteria for AIDS?
Common AIDS infection? |
Less than 200 CD4 cells/mm^3
Common infection: Pneumocystis carinii pneumonia Side note: Risk of AIDS after HIV infection is 0.24%/year for first 2 years, then progressively increases |
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What is a long-term nonprogressor?
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HIV+ population that have not developed AIDS
Not known why; may be mutant virus, enhanced cell mediated immune response, lack of co-receptor (New drug combos may allow for immunologic reconstitution) |
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HIV Testing:
First and Second Line |
First Line: HIV Ab testing via ENZYME-LINKED IMMUNOASSAY (ELA), if positive run 2nd line
Second Line: Western Blot = confirmatory test and show specific HIV ab patterns; much more expensive than ELA |
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What HIV clades? How does they affect vaccine development?
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Subtypes that differ by variations in the viral envelope
Ab's to strain of one subtype may not cross-neutralize others-->vaccine concerns (Commercial Ab screening tsts pick up almost all subtypes except O and others rare in US) |
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Should a heathcare worker be concerned by needle prick with HIV patient?
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Perhaps; there's a <0.3% chance of infection
HIV IS NOT HIGHLY CONTAGIOUS--need intimate body fluid inoculation |
