[Survey of HIV drug resistance threshold in Zhejiang province from 2009 to 2011]

To survey the prevalence of drug resistant HIV in Zhejiang province in 2009-2011.

WHO truncated sequential sampling technique was adopted annually by using 63, 62 and 57 samples of newly diagnosed as HIV positive and aged 16-25 years in Hangzhou, Ningbo and Wenzhou from 2009 to 2011, respectively. RNA was prepared and HIV pol region was amplified by RT-PCR and nested PCR. Pol genetic mutation associated with drug resistance was analyzed.

The success rates for sequence acquisition of the survey were 82.5% (52/63), 95.2% (59/62) and 94.7% (54/57) from year 2009 to 2011, respectively, and the main subtype was CRF01_AE (68.5% (37/54)-71.2% (37/52)). A total of 4 surveillance drug-resistance mutation (SDRMs), 2 SDRMs and 2 SDRMs were found by analyzing the 47 sequences each year, sampled from year 2009 to 2010, respectively, indicating that the prevalence of drug resistant HIV stains was moderate in 2009, and low for the next two years (2010-2011). A total of 8 individuals with drug resistant HIV stains found in this study were all infected by sexual transmission, especially in homosexual transmission (6 cases), and the main subtype was CRF01_AE (7 cases). SDRMs for protease inhibitor (PI), nucleotide HIV-reverse transcriptase inhibitor (NRTI) and non-NRTI (NNRTI) (L90M, T215S and Y188L) were all found in one case.

The prevalence of drug resistant HIV stains in major areas with AIDS epidemic in Zhejiang province was low in 2009-2011.