A stochastic model of the HIV epidemic for heterosexual transmission involving married couples and prostitutes: I. The probabilities of HIV transmission and pair formation

To assess effects of risk factors on the HIV epidemic by heterosexual transmission and the role of prostitutes, in this paper we consider four populations and derive the probabilities of HIV infection in these populations. The four populations considered are the single males, the single females, the married couples, and the prostitutes. It is shown that prostitutes form a stepping stone for the HIV epidemic by heterosexual transmission. Thus, in a society in which homosexual transmission and IV drug use are not frequent, the HIV epidemic can hardly be maintained without prostitutes.