HIV belongs to the genus Lentivirus. They are characterised by a long incubation period. Lentiviruses can deliver a significant amount of viral RNA into the DNA of the host cell and have the unique ability among retroviruses of being able to infect non-dividing cells.

HIV infects all T-cells and B-cells, thereby eradicating the complete immune system.

Lentiviruses are transmitted as single-stranded, positive-sense, enveloped RNA viruses.

env gene codes for a protein called gp160 that is broken down by a cellular protease to form gp120 and gp41.

The Psi element is involved in viral genome packaging and recognised by Gag and Rev proteins.

Western blot is the confirmatory test for HIV. Only specimens that are repeatedly reactive by ELISA and reactive by Western blot are considered HIV-positive and indicative of HIV infection. Specimens that are repeatedly ELISA-reactive occasionally provide an indeterminate Western blot result, which may be either an incomplete antibody response to HIV in an infected person or nonspecific reactions in an uninfected person.

RNA polymerase is absent in RNA viruses.

The first HIV protease inhibitor, saquinavir, is a peptidomimetic hydroxyethylamine and was marketed in 1995.

Dr. Suniti Solomon holds the honour of documenting the first evidence of HIV infection in the country way back in 1986.

It is a myth. Contact with sweat or tears has never been shown to result in transmission of HIV.

The estimated life of a person with HIV without treatment is 9-11 years depending upon the strain causing the infection.

The envelope protein allows the virus to attach to the host surface, causing fusion of viral and host membrane and releasing the viral contents into the cell and initiating the infectious cycle. As proteins are highly antigenic and this is the sole viral surface protein, it is at present the major target for HIV vaccine efforts.

Positive single-stranded RNA codes for the virus's nine genes. They are gag, pol and env, tat, rev, nef, vif, vpr, vpu, and sometimes a tenth tev, which is a fusion of tat env and rev.

Reverse transcriptase enzyme is present in viral particle. It gets transferred to the host cell along with genome.

HIV-2 came to humans from sooty mangabeys.