Aids and hiv
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Transcript of Aids and hiv
HIV
ByR.Parthasarathy
History of HIV/AIDSIn 1981
Kaposi’s sarcoma Pneumocystis cariniipneumoniaIn 1983
Luc Montagnier and Françoise Barré-Sinoussi isolated retrovirus from lymphadenopathic patients.
Named it as lymphadenopathy associated virus (LAV).
History of HIV/AIDSIn 1984
In 1986
Robert Gallo and colleagues, isolated and cultured certain retrovirus.
Named it as human T cell lymphotrophic virus – IIIor HTLV - III
International Committee on Virus Nomenclature give a generic name
Human immunodeficiency virus (HIV)
StructureSubgroup: lentivirus.
Lenti means slow (greek)
It is 32000 years old.
Family: Retroviridae.
Sperical enveloped virus. 90-120nm
2 identical +ve sense ssRNA,
Three enzymes
Reverse transcriptase (RT)
Protease (PR)
Integrase (IN)
Viral gens and antigenStructural genes Functions
GagDetermines the core and shell of the virus.P55 (p15,p18,p24) -p24 detected in the early stage of infection (before antibodies)
pol Codes polymerase reverse transcriptase and proteaseP31,p51,p66
envDetermines the synthesis of envelope glycoprotein gp160 - gp120 which forms the surface spike (72) - gp 41 which forme transmembrane protein.
Non structural genes FunctionsTat (trans activating gene) Enchance all viral genes
Nef ( -ve factor gene)Rev ( regulator of viral gene)
Regulates viral replicationEnchace the expression of structural protein
Vif (viral infectivity factor) Influence infectivity of viral particles.
Vpu and vpx (1&2) Enchance maturation and release of virus
Viral gens and antigenNon structural genes Functions
vpr Stimulate promoter region
LTR sequence Contain sequence giving promoter, enhancer and integration signals.
Viral classification and subtypes
M – majorN – newO – outlierP – pending
Mode of transmission
Types of exposure Chance of infection per exposure(ApproX)
Blood and blood products >90%Tissue and organ donation 50-90%Sexual transmission 0.1 – 1.0%Through injections and injuries 0.5 – 1.0%Mother to fetal baby 30%
Clinical symptoms are classified as mentioned below:
Lab dignosis
Screening, measuring the antibodies to Hiv using ELISA
Confirmed by western Blot
Treatment
1. Nucleoside and non nucleoside analogues - inhibits reverse transcriptase enzyme.
Eg: Zidovudine (Azidothmidine, AZT), Didanosine, Zalcitabine, lamivudine
2. Protease inhibitors
- inhibits protease enzyme
Eg: sanquinavir, Ritonavir, indinavir
HAART(highly active antiretroviral therapy)
- combined therapy(Both)
- This method is currently used.
Treatment
References
• Anathanarayan and paniker’s, Text book of microbiology, 7th edition.
• Sherrai medical microbiology, 5th edition.• Net sources
www.avert.com
www.cdc.gov
www.unaids.org