The Origin of HIV

Neelam Rani, Vijaya Alla

What is HIV?

Group: Group VI (ssRNA)

Family: Retroviridae

Genus: Lentivirus

Species: HIV-1, HIV-2

Virus Structure

Enveloped Two copies of ssRNA Reverse transcriptase Bullet-shaped capsid 72 spikes Only 9 genes

LifeCycle

What is SIV?

Retrovirus that infects primates

Virus is transmitted sexually

It does not cause disease in natural host

May cause SAIDS in non-natural hosts

Relationship: HIV & SIV

HIV-1 evolved from SIVcpz found in a chimpanzee subspecies Pan troglodyte troglodyte

HIV-2, the less virulent form, evolved from SIVsm found in sooty mangabeys

Theories on Origin

Hunter Theory

Contaminated Needle Theory

OPV Theory

Colonial Theory

Earliest Cases

1959 - adult male in Congo

1969 - teenager in St.Louis

1976 - sailor in Norway

CausesCauses

TravelTravel Blood IndustryBlood Industry Drug UseDrug Use IntercourseIntercourse BirthBirth

HIV’s Progression to AIDS

Stage I - asympotomatic Stage II - mucocutaneous

maifestations, URI Stage III - chronic diarrhea, severe

bacterial infections, pulmonary TB Stage IV - taxoplasmosis of brain,

candidiasis of esophagus,trachea, lungs and kaposi’s sarcoma

Geography

Sub-Saharan Africa, South Asia, and the Caribbean are the hardest hit

WHO estimates 36-44 million are infected with HIV as of Dec 2004

MedicationsMedications

No cureNo cure No vaccineNo vaccine HAART “cocktail” - contains HAART “cocktail” - contains

protease inhibitors and two protease inhibitors and two reverse transcriptase inhibitorsreverse transcriptase inhibitors

Antisense therapy – fragment of Antisense therapy – fragment of DNA that binds to viral mRNA to DNA that binds to viral mRNA to prevent translationprevent translation

References

http://www.reference.com/browse/wiki/Simian_immunodeficiency_virus

http://www.reference.com/browse/wiki/AIDS

http://en.wikipedia.org/wiki/HIV http://www.fda.gov/fdac/features/1999/

499_aids.html http://www.avert.org/origins.htm