Table 2.

HIV-1 reverse transcriptase sequences according to subtype and treatment exposure: datasets used to provide mutation frequency data for the HIVseq Program (September 2005)

	RTI naivea			NRTI experienced but NNRTI naiveb			NNRTI experiencedb
Subtype	Virusesc	Persons	Citationsd	Virusesc	Persons	Citationsd	Virusesc	Persons	Citationsd
Subtype B	2080	2077	101	4245	3205	106	3334	1772	76
Non-B Subtypes
A	454	453	50	60	54	16	251	222	11
AE	444	443	47	196	191	15	116	111	12
AG	441	441	34	63	56	15	76	66	8
C	888	863	67	249	198	23	246	222	14
D	135	135	30	75	69	15	206	160	13
F	123	123	32	76	69	19	76	67	12
G	127	127	26	122	118	4	204	194	7
Non-B total	2612	2585		841	755		1175	1042

^aRTI-naive persons are those who never received a nucleoside (NRTI) or non-nucleoside (NNRTI) reverse transcriptase inhibitor regardless of their protease inhibitor treatment history.

^bTwo separate categories for NRTI-experienced persons were created to enable the identification of mutations associated with NRTI therapy (by comparing viruses from RTI-naive persons with those from NRTI-experienced but NNRTI-naive persons) and those associated with NNRTI therapy (by comparing viruses from NNRTI-experienced persons with those from both categories of NNRTI-naive persons.).

^cTotal number of virus isolates for which sequences exist in the Stanford HIV RT and Protease Sequence Database (according to subtype and treatment). The number of viruses is higher than the number of patients because some patients have had viruses assessed from multiple time points.

^dNumber of different published references (or unpublished studies associated with GenBank submissions) from which the sequence data were obtained.