Question

Please, kindly explain ETIOLOGY OF HIV. Thank you

Answer 1

HIV refers to HUMAN IMMUNODEFICIENCY VIRUS

It causes a disease called as AIDS that is acute immunodefeciency syndrome.it is a unique, STI which have no manifestation in genitalia but profound systemic manifestation.

HIV is a virus which belongs to the group Retrovirus family and genus lentivirinae and

is an enveloped virus

genetic material :- single stranded RNA virus

Genome of HIV contains

three structural genes

1) Gag(group specific antigen):- core protein : p24

                                                  matrix protein :p17

2)Pol (polymerase)   :-Reverse transcriptase:p51

                                   Protease:p11

                                  Integrase:-p32

3Env(envelope) :- outer envelope glycoprotein :gp120

                               Trans membrane envelop glycoprotein :gp41

Six Non structural genes

          Vif, vpr, vpu,rev,tat,nef

Pathogenesis:- it attaches to the CD4 receptors on T cells and destroys it, these leads to suspectible of individuals to virus and many oppourtunistic infection

two antigenic types are there one is HIV1 &HIV 2

	HIV1	HIV2
Virulence	more	less
Envelope antigens	gp120 and gp41	gp140 and gp36
Matrix protein antigens	p17	p16
Capsid protein antigen	p24	p26

Modes of transmission

ROUTE	EFFICACY
Blood transfusion	>90%
Perinatal	13 - 40%
Sexual intercourse anal vaginal	1% per episode 0.1% per episode
Intravenous drug use	0.5 -1%
Needle stick injury	0.3%