Table 4.

Prevalence of Predicted Intermediate or High-Level Resistance to DHHS Recommended Starting Drugs According to Stanford HIVDB 5-Point Resistance Scale Among 536 Antiretroviral-Naive MSM HIV Patients in You'an Hospital, Beijing, China

Resistant to	Total n (%)	AHI/EHI n (%)	CHI n (%)	p-Value
Any drug	13 (2.4)	6 (2.3)	7 (2.6)	0.800
NRTIs	1 (0.2)	0	1 (0.4)	0.320
3TC/FTC	0	0	0
ABC	1 (0.2)	0	1 (0.4)
AZT	0	0	0
TDF	0	0	0
NNRTIs	8 (1.5)	4 (1.5)	4 (1.5)	0.983
EFV	7 (1.3)	3 (1.1)	4 (1.5)
NVP	6 (1.1)	2 (0.8)	4 (1.5)
RPV	4 (0.7)	2 (0.8)	2 (0.7)
PIs	7 (1.3)	3 (1.1)	4 (1.5)	0.718
LPV/r	0	0	0
DRV/r	0	0	0
FPV/r	3 (0.6)	1 (0.4)	2 (0.7)
ATV/r	3 (0.6)	0	3 (1.1)
SQV/r	5 (0.9)	2 (0.8)	3 (1.1)

The Stanford HIVDB algorithm estimated inferred levels of resistance to 19 FDA-approved antiretroviral drugs. Each HIV-1 drug resistance mutation is assigned a drug penalty score and a comment. Using the total drug score, the program reports one of the following levels of inferred drug resistance: (i) 0 to 9, Susceptible, no evidence of reduced susceptibility compared with wild type; (ii) 10 to 14, Potential low-level resistance. The virus is likely to be fully susceptible yet it contains mutations that may be indicative of previous exposure to the ARV class of the drug; (iii) 15 to 29, Low-level resistance. Virus isolates of this type have reduced in vitro drug-susceptibility and/or patients with viruses of this genotype may have a suboptimal virologic response to treatment compared with the treatment of a wild type virus; (iv) 30 to 59, The genotype suggests a degree of drug resistance greater than low-level resistance but lower than high-level resistance; (v) >=60, the genotype is similar to that of isolates with the highest levels of in vitro drug resistance and/or patients infected with isolates having similar genotypes generally have little or no virologic response to treatment with the drug.

DHHS, Department of Health and Human Services.