CD4 and immunodeficiency disease: Immunodeficiency because of HIV infection has been presented as a major risk factor.8–10 One major European study conducted in 2012 followed 35,000 ART-treated PLHIV with the CD4+T cell count (CD4) >500 cells/μL over a mean period of 3.5 years11 and found mortality rates among PLHIV, excluding people who inject drugs (PWID), to be similar to the rates found in the general population (0.37/100 PY).