These findings are consistent with those from several clinical or research cohorts in North America and Europe, which reported non-white ethnicity/migrants [21,22], younger age [22-24], a CD4 cell count of less than 200 cells/mm3 [22,24] or a high CD4 count being associated with retention in care [25,26], non-use of HAART [24,27,28], a detectable viral load [21,22,24,27,28] or absence of an AIDS-defining illness as predictors of loss to follow up [24-26]. This evidence concerns the gene CD4 and AIDS.