CD4 and HIV infectious disease: In PLWH, HIV infection increases the risk of progressing from TB infection to TB disease.[4] Furthermore, TB may act as cofactor in the progression of HIV infection by increasing the HIV viral load through inducing a faster HIV replication and/or by contributing to a reduction in the CD4 cell count.[5] The widespread use, since 1996, of highly active antiretroviral therapy (HAART) has substantially improved the prognosis of HIV-infected patients both in industrialised and low-income settings [6] and survival in HIV/TB co-infected individuals.[7], [8]