Table 1.

Baseline Age, HIV-1 RNA, IAS Resistance Mutations, HIV-1 Subtype, ART for reduction of MTCT and First-line ART by Randomized Switch-threshold

		Randomized switch-threshold
		Low (n=134)		Higher (n=129)		Total (n=263)
Age (years), median (IQR) [range]		6.1		6.9		6.5
		(2.5–13.1)		(3.1–12.5)		(2.8–12.9)
		[0.3–17.8]		[0.1–17.5]		[0.1–17.8]
HIV-1 RNA (c/ml), median (IQR)		99646		119356		107813
		(35488–446704)		(28732–434369)		(31251–446704)
Baseline resistance test availablea		121	100%	118	100%	239	100%
Any major mutations		7	6%	3	3%	10	4%
1 or 2 mutations		7		2		9
≥3 mutations		0		1		1
NNRTI K103N		1		1		2
NNRTI V108I		1		0		1
NNRTI Y181C		2		1		3
NNRTI Y188L		1		0		1
PI Q58E		1		0		1
NNRTI K101P Y181C		1		0		1
NRTI D67N K219Q, NNRTI K103N		0		1		1
HIV-1 subtype availableb		128	100%	121	100%	249	100%
HIV-1 subtype	B	52	41%	49	41%	101	41%
	C	13	10%	12	10%	25	10%
	F	25	20%	23	19%	48	19%
	A/CRF_AG/D/G	25	20%	27	22%	52	21%
	unclassified	13	10%	10	8%	23	9%
ART use prior to randomization for reduction of MTCTc		22	100%	17	100%	39	100%
In utero (to the mother)		4	18%	6	35%	10	26%
1 day	ZDV+NVP	0		1		1
1–24 weeks	ZDV+3TC+NVP	2		2		4
1–2 weeks	ZDV+3TC+NFV	1		1		2
7–28 weeks	ZDV	1		2		3
Delivery/Post partum (to the infant)		22	100%	16	94%	38	97%
single-dose	NVP, 1–4 weeks ZDV+3TC	0		2		2
single-dose	NVP, 3–6 weeks ZDV	2		1		3
1–12 weeks	ZDV	19		12		31
5–6 weeks	ZDV, 3–6 weeks 3TC	1		1		2
First-line NNRTI ART		67	100%	65	100%	132	100%
EFV with		43	64%	39	60%	82	62%
ABC+3TC		15		10		25
ZDV+3TC		17		18		35
d4T+3TC		6		3		9
other NRTIsd		5		8		13
NVP with		24	36%	26	40%	50	38%
ABC+3TC		3		6		9
ZDV+3TC		15		11		26
d4T+3TC		3		8		11
other NRTIse		3		1		4
First-line PI ART		67	100%	64	100%	131	100%
LPV/r with		29	43%	36	56%	65	50%
ABC+3TC		10		12		22
ZDV+3TC		10		20		30
d4T+3TC		6		4		10
other NRTIsf		3		0		3
NFV with		37	55%	27	42%	64	49%
ABC+3TC		3		3		6
ZDV+3TC		12		9		21
d4T+3TC		13		10		23
other NRTIsg		9		5		14
Other protease inhibitor		1	1%	1	2%	2	2%
ZDV+3TC+high-dose ritonavir		0		1		1
ddI+3TC+fosamprenavir/ritonavir		1		0		1

^aIncludes 1 test where only the protease gene was sequenced.

^bAvailable from 239 baseline resistance tests and 10 resistance tests during follow-up.

^cFor 3/5 children who received single-dose NVP, the mother also received NVP in utero.

^d10 ZDV+ddI, 2 3TC+ddI, 1 ddI+FTC

^e1 ZDV+ddI, 1 ZDV+ABC, 2 ddI+d4T

^f1 ZDV+ddI, 2 ZDV+ABC

^g13 ZDV+ddI, 1 ddI+d4T

Children are displayed in 2 groups defined by their randomized switch threshold (low=1000c/ml, higher=30000c/ml). IAS = International AIDS Society-USA, MTCT = mother-to-child transmission, ART= antiretroviral therapy, PI = protease inhibitor, NNRTI = non-nucleoside reverse transcriptase inhibitor, NRTI = nucleoside reverse transcriptase inhibitor, ZDV = zidovudine, NVP = nevirapine, 3TC = lamivudine, EFV = efavirenz, ABC = abacavir, d4T = stavudine, LPV/r = lopinavir/ritonavir, NFV = nelfinavir, ddI = didanosine, FTC = emtricitabine