Introduction: The development of resistance to antiretroviral therapy (ART) reduces the effectiveness of these drugs in HIV-infected children.
Methods: We performed a cross-sectional study in 86 vertically HIV-infected children, divided into four groups according to prior treatment: group 1: nucleoside reverse transcriptase inhibitor (NRTI), group 2: NRTI and non-nucleoside reverse transcriptase inhibitor (NNRTI), group 3: NRTI and protease inhibitor (PI), group 4: NRTI, NNRTI and PI.
Results: In group 1 (11 children), the median treatment duration was 35 months (26 to 108). Nucleoside-associated mutations (NAMs) were found in 10 of these patients and the Q151M multiresistance mutation was found in two. The three children in group 2 were treated for 9, 32 and 42 months with NRTI and NNRTI. One child showed three NAMs and another showed Q151M. Two children had the K103N mutation. Group 3 (36 children) received treatment with NRTI and PI for 48.0 +/- 27.6 and 23.0 +/- 14.6 months, respectively. NAMs were observed in 94 % of the patients in this group, and one child showed the Q151M mutation. In group 4 (36 children) total treatment duration was 70.0 +/- 36.1 months (13.0 +/- 12.1 months with NNRTI, and 39.0 +/- 14.3 months with PI). NAMs were observed in all patients in this group, and Q151M was found in three children. K103N and Y181C were detected in 24 (67%) and 10 (28%) of the children respectively, while 32 (90%) showed primary mutations to PI.
Conclusions: A high prevalence of resistance mutations to NRTI and early appearance of resistance to NNRTI were observed in treated children.