¹Professor, Department of Statistics, Annamalai University, Annamalai Nagar- 608002 (INDIA)
²Research Scholar, Department of Statistics, Annamalai University, Annamalai Nagar- 608002 (INDIA)
Email.ramajayam82@yahoo.com    Email.srelangovan@rediffmail.com

It is now known that the immunodeficiency virus (HIV) can be transmitted through a variety of contact mechanisms that include homosexual intercourse, heterosexual intercourse and needle sharing among intravenous drug abusers. The level of infectivity plays a major role in applying epidemic models to project the spread of the virus and in evaluating various intervention strategies. As a retrovirus HIV shows application error rate and leads to the creation of distinct viral genomes with different immunological properties. This character of HIV is called antigenic diversity. Every contact contributes to the transmission of some HIV which in turn contributes of the increase of antigenic diversity. Total damage crosses the threshold of any one transmission then the HIV infected person reaches the threshold level. Most of the behavior in the stochastic model for the expected time strongly depends on initial conditions. In this paper the expected time and variance of the estimated threshold level through two modes of transmission using three parameter Generalized Rayleigh Distribution has been derived. The analytical results are substantiated with suitable numerical illustrations.