CD4 and AIDS: Again, the importance of early recognition of neurocognitive deficits and the treatment of the infection was emphasized.[29] In a further study, 284 HIV-positive children and adolescents from Thailand and Cambodia were divided into the following 2 groups: “early treatment” and “late treatment.” “Early” was defined as therapy beginning simultaneously at baseline irrespective of age, whereas in the second group, study therapy was started only if the CD4 cell count percentage fell below 15% or an AIDS-defining event had occurred.