Open Access Highly Accessed Research article

Genetic diversity and drug resistance among newly diagnosed and antiretroviral treatment-naive HIV-infected individuals in western Yunnan: a hot area of viral recombination in China

Min Chen1, Yanling Ma1, Song Duan2, Hui Xing3, Shitang Yao2, Yingzhen Su1, Hongbing Luo1, Li Yang1, Huichao Chen1, Liru Fu1, Aijuan Qu4, Chin-Yih Ou5, Manhong Jia1* and Lin Lu1*

Author Affiliations

1 Yunnan Center for AIDS/STD Control and Prevention, Yunnan Center for Disease Control and Prevention, Kunming, Yunnan, 650022, China

2 Department of HIV/AIDS Control and Prevention, Dehong Center for Disease Control and Prevention, Dehong, Yunnan, 678400, China

3 National Center for AIDS/STD Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, 102206, China

4 Laboratory of Metabolism, Center for Cancer Research National Cancer Institute, National Institutes of Health, Bethesda, MD, 20892, USA

5 Global AIDS Program in China, U. S. Centers for Disease Control and Prevention, Beijing, 100600, China

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BMC Infectious Diseases 2012, 12:382  doi:10.1186/1471-2334-12-382

Published: 28 December 2012

Abstract

Background

The emergence of an HIV-1 epidemic in China was first recognized in Dehong, western Yunnan. Due to its geographic location, Dehong contributed greatly in bridging HIV-1 epidemics in Southeast Asia and China through drug trafficking and injection drug use; and also extensively to the HIV genetic diversity in Yunnan and China. We attempt to monitor HIV-1 in this area by studying the HIV-1 genetic distribution and transmitted drug resistance (TDR) in various at-risk populations.

Methods

Blood samples from a total of 320 newly HIV-1 diagnosed individuals, who were antiretroviral therapy (ART)-naive, were collected from January 2009 to December 2010 in 2 counties in Dehong. HIV-1 subtypes and pol gene drug resistance (DR) mutations were genotyped.

Results

Among 299 pol sequences successfully genotyped (93.4%), subtype C accounted for 43.1% (n=129), unique recombinant forms (URFs) for 18.4% (n=55), CRF01_AE for 17.7% (n=54), B for 10.7% (n=32), CRF08_BC for 8.4% (n=25) and CRF07_BC for 1.7% (n=5). Subtype distribution in patients infected by different transmission routes varied. In contract to the previous finding of CRF01_AE predominance in 2002-2006, subtype C predominated in both injecting drug users (IDUs) and heterosexually transmitted populations in this study. Furthermore, we found a high level of BC, CRF01_AE/C and CRF01_AE/B/C recombinants suggesting the presence of active viral recombination in the area. TDR associated mutations were identified in 4.3% (n=13) individuals. A total of 1.3% of DR were related to protease inhibitors (PIs), including I85IV, M46I and L90M; 0.3% to nucleoside reverse transcriptase inhibitors (NRTIs), including M184I; and 2.7% to non-nucleoside reverse transcriptase inhibitors (NNRTIs), including K103N/S, Y181C, K101E and G190A.

Conclusion

Our work revealed diverse HIV-1 subtype distributions and intersubtype recombinations. We also identified a low but significant TDR mutation rate among ART-naive patients. These findings enhance our understanding of HIV-1 evolution and are valuable for the development and implementation of a comprehensive public health approach to HIV-1 DR prevention and treatment in the region.

Keywords:
HIV-1; Genetic diversity; Drug resistance; Injecting drug use; Dehong; China