Fig 6. Probability of HIV-1 infection as dictated by CD4+ T cell count and damaged tissue amount.

(A) Spatial depiction of the probability of HIV-1 infection within one representative simulated tissue sample. Left: CD4+ T cell counts (cells/mm²). Right: the amount of tissue damage in the simulation region at the time of exposure. (B) The probability of an HIV-1 infection when the simulation region in (A) is exposed to three different seminal HIV-1 concentrations during vaginal intercourse. Combining grid site-specific probabilities leads to an overall 0.65%, 6.18% risk, or 47.75% risk of HIV-1 infection establishment within the model region depending on the HIV-1 exposure level. (C) Probability of HIV-1 infection across 61 simulation tissue samples and for each seminal HIV-1 concentration. HIV-1 risk is plotted against the number of CD4+ T cells per mm² and the percentage of herpetic lesion tissue damage within the simulation region at the time of HIV-1 introduction. The single red points indicate the risk of HIV-1 contraction if tissue is healthy. Linear planes of fit for each set of data points are also shown (Eqs 1, 2 and 3 from left to right, with adjusted R² = 0.9702, 0.9797, and 0.9951 respectively).