RESUMEN
Objective: To understand the prevalence of drug resistance in treatment-naive injecting drug users (IDUs) infected with HIV-1 in Guangzhou. Methods: HIV-1 RNA were extracted from the serum specimens of the newly confirmed HIV-1 positive IDUs living in Guangzhou, being infected through injecting drug use and receiving no antiretroviral therapy at the time of confirmation during 2008-2015. Full sequence of pol protease (PR) gene and partial sequence of reverse transcriptase (RT) gene were amplified by nested reverse transcription polymerase chain reaction (nested-PCR) and sequenced. After that, data were submitted to the HIV resistance database of Stanford University for drug resistance analysis. Results: Among the 518 HIV-1 infected IDUs, HIV-1pol gene segments were successfully obtained from the serum samples of 407 HIV-1 infected IDUs (78.57%) aged 18-64 (37.44±8.14) years. Among them, males accounted for 89.68% (365/407), those of Han ethnic group accounted for 89.93% (366/407), the unmarried accounted for 55.28% (225/407), and those with education level of junior high school or below accounted for 83.78% (341/407). The distribution of subtypes was predominated by CRF07_BC (47.18%, 192/407), followed by CRF01_AE (23.83%, 97/407), CRF08_BC (22.85%, 93/407), and other subtypes (6.14%, 25/407). The overall prevalence of drug resistance was 3.44% (14/407). The prevalence of drug resistance to protease inhibitors, nucleoside reverse transcriptase inhibitors and non-nucleoside reverse transcriptase inhibitors were 1.47%(6/407), 0.25% (1/407) and 1.72% (7/407) respectively. The mutation rate was 12.29% (50/407). No major drug resistance mutation was detected in protease and nucleoside reverse transcriptase regions. Higher rate of V179E mutation in the non-nucleoside reverse transcriptase region was detected in other subtypes and subtype CRF07_BC. Mutation seemed to have occurred in all 8 cases of subtype CRF55_01B in other subtypes. The highest mutation rate of E138A was detected in subtype CRF08_BC (3.23%). Two cases were resistant to all four drugs of NNRTIs. Conclusions: The prevalence of drug resistance in treatment-naive HIV-1 positive IDUs remained at a relatively low level during 2008-2015, in Guangzhou. Most infections were sensitive to existing antiviral drugs. However, drug resistance surveillance in IDUs infected with HIV should be strengthened to prevent the prevalence of multi-drug resistance and cross drug resistance.