Table 2.

Detection of NRTI and NNRTI Resistance before HAART Initiation

			ViroSeq		LigAmp (subtype A and D only)
Virally suppresseda	sdNVP exposed	No. tested	No. results	No. (%) with resistance	No. tested	No. (%) with resistance
Yes	No	29	25	0	16	1d
	Yes	27	24	1b	20	1e
	Total	56	49	1 (2.0%)	36	2 (5.6%)
No	No	16	14	0	8	0
	Yes	11	11	1c	7	3c,f,g
	Total	27	25	1 (4.0%)	15	3 (20.0%)
Overall		83	74	2 (2.7%)	51	5 (9.8%)

Pretreatment samples were analyzed with the ViroSeq HIV Genotyping System for detection of mutations in HIV protease and reverse transcriptase. Fifty-one of the 61 samples with subtype A or D HIV were also tested with the LigAmp assay for detection of selected NVP-resistance mutations (K103N, Y181C, and G190A); 10 subtype A or D samples had insufficient DNA remaining after genotyping for analysis with the LigAmp assay. The table shows the number of samples tested with each assay (no. tested), the number of samples with results with ViroSeq (no. with results), and the number of samples with resistance mutations detected by using each assay (no. with resistance). For children who had one or more resistance mutations detected in the pretreatment sample, the age of the child, HIV subtype, mutation(s) detected, and level of mutation detected (for LigAmp) are detailed in the footnotes.

^aChildren were characterized as virally suppressed if their viral load was <1,000 copies/ml throughout the study period.

^bOne-year-old child with subtype D HIV; T215A detected by ViroSeq.

^cOne-year-old child with subtype A HIV; Y181C detected by ViroSeq and LigAmp (at 1.4%).

^dFive-year-old child with subtype D HIV; Y181C detected by LigAmp (at 2.6%).

^eThis child was 1.4 years old with subtype D HIV; Y181C detected by LigAmp (at 5.2%).

^fThis child was 1.4 years old with A/F recombinant HIV; Y181C detected by LigAmp (at 2.3%).

^gSix-month-old child with subtype D HIV; Y181C detected by LigAmp (at 3.9%).