In addition, the following characteristics were also compared between the groups but showed no significance: age at time of diagnosis, acute retroviral syndrome (ARS), CDC class, AIDS defining illnesses, other sexually transmitted diseases, most probable route of HIV infection (homo/bisexual, heterosexual or other), relationship with the source of HIV infection (sex with anonymous person or stable relationship), viral load and CD4 cell count at the time of diagnosis and duration of HIV infection at the time of diagnosis as determined by incidence algorithm (recent or long-standing). This evidence concerns the gene CD4 and sexually transmitted disease.