Unlike other studies that have identified being male in gender [3], younger age [9, 10,  12,  19], low current body mass index (BMI) [3], poor adherence to treatment [9, 10,  12,  13,  19], advanced WHO staging [10], low baseline and low current CD4 count [8, 10,  19,  20], longer duration on ART [19] and TB/HIV co-infection as factors positively associated with virological treatment failure, some are subject of consensus and others not. This evidence concerns the gene CD4 and coinfection.