Projecting the impact of HAART on the evolution of HIV’s life history

Alternative reproductive strategies are introduced to HIV population models. A time-invariant stage-classified Lefkovitch matrix population model hypothesizes antiretroviral innovations such as HAART may select for, among other possibilities, an HIV with a semelparous life history and a precocious senescence. The senescence may be embodied by an accelerated time to AIDS or related pathogenesis. The model also shows populations of HAART-treated iteroparous infection can grow at rates comparable to their ‘wildtype’ counterparts even in the face of nearly full nullification of transmissibility for both the asymptomatic and AIDS stages. Indeed, increasing survivorship and decreasing the transition rate from the asymptomatic stage to AIDS, as HAART regimens aim to do, may induce the greatest increase in infection population size. Because infection survivorship is physiologically enmeshed with host survivorship the asymptomatic stage becomes under HAART a demographic shield against epidemiological intervention. The results appear to exemplify how pathogens use processes at one level of biological organization to defend themselves against impediments directed at them at another.