Background:  Few data exist as to the most effective regimens for children with vertically acquired HIV infection. Many countries have limited regimes based on nucleoside analog reverse transcriptase inhibitor (NRTI) backbones combined with either a non-NRTI (NNRTI) or a protease inhibitor (PI). Often nevirapine (NVP) is used for vertical transmission prevention (PMTCT) in these settings. This study describes the outcomes of a cohort of 370 children on HAART, and determinants thereof.

Methods:  Data were collected prospectively on all children receiving HAART through the infectious diseases clinic of a public hospital. Children were started on HAART that included a NRTI backbone, and either a NNRTI (NVP or efavirenz [EFV]) or a PI (lopinavir [LPV]/ritonavir [r] or ritonavir [RTV]) as their third drug. Viral load and CD4 percentage were collected 6-monthly, and weight and height at every visit. Weight-for-age z-score and height-for-age z-score were calculated using WHO standard curves.

Results: The median baseline age of the cohort was 26.9 months, and median baseline CD4 percentage was 13. Few children were exposed to NVP for PMTCT. Median baseline weight-for-age z-score and height-for-age z-score were –2.7 and –3.0, respectively. There were obvious improvements in all parameters after the initiation of HAART. Exactly 50% of the patients received PI regimens. There was no significant difference in the baseline characteristics of patients on the different regimens with regard to viral load, CD4 percentage, weight-for-age z-score, or height-for-age z-score, however the age for those started on NNRTI was significantly higher (44.1 vs 32.0 months, p = 0.001). There was a significantly better virological suppression achieved in those receiving PI at all times through 48 months, although that difference was not apparent in CD4 percentage, weight-for-age z-score or height-for-age z-score, nor in survival. In a multivariate analysis predicting virological suppression, PI-based regimens were strongly associated with virological suppression (OR 3.69; 95%CI 2.13 to 6.39). Baseline CD4 percentage (OR 1.03; 1.01 to 1.06), weight-for-age z-score (OR 1.30; 1.11 to 1.53), and age (OR 1.33 per year increase; 1.19 to 1.48) were further associated with virological suppression.

Conclusions:  Despite profound improvements in outcomes for all children on HAART, it appears that NNRTI regimens may be inferior to PI regimens in our setting with current protocols. These finding may be due to insufficient dosage of NVP or due to viral resistance patterns. However, as shown by growth and CD4 outcomes, this virological inferiority may not be clinically significant.