Characteristics of the data sets and estimated evolutionary parameters.

N: number of sequences per discrete location/country (k) in the DRC and in Central and East Africa (CEA). Δt = time interval of sequence sampling in this study. ρ indicates the Pearson’s correlation coefficient between N and HIV prevalence in 2013 for Burundi, DRC, Kenya, Rwanda, Tanzania and Uganda as recorded by UNAIDS [113]. P-values indicate statistical significance under a linear regression parametric model. The cumulative number of sequences per country and HIV seroprevalence over time can be found in S5 Fig. R2 indicates the correlation between genetic divergence and sampling dates (S6 Fig).