Prevalence of antiretroviral drug resistance in treatment-naive injecting drug users infected with HIV-1 in Guangzhou, 2008-2015 / 中华流行病学杂志

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.

Characteristic and dynamic of HIV-1 subtype distribution in men who have sex with men in Guangzhou, 2008-2015 / 中华流行病学杂志

Objective: To understand the characteristics and dynamic of HIV-1 subtype distribution in men who have sex with men (MSM) in Guangzhou between 2008 and 2015. Methods: HIV-1 RNAs were extracted from serum samples of the individuals newly diagnosed with HIV-1 infection among MSM living in Guangzhou between 2008 and 2015. The pol gene segments of HIV-1 genome from these RNA samples were amplified by nested reverse transcription polymerase chain reaction (nested-PCR) and were sequenced. Subsequently, the phylogenetic tree was reconstructed using pol sequences of samples and references together and the subtype of HIV-1 was determined. The distributions of HIV-1 subtypes detected in MSM with different demographic characteristics in different years were compared. Results: A total of 2 210 pol gene segments were successfully obtained from 2 473 serum samples of the MSM. The average age of 2 210 MSM was 30.19 years with standard deviation of 8.22 years, the unmarried MSM and those in Han ethnic group accounted for 73.39% and 90.81%, respectively. The proportion of subtype CRF07_BC (38.10%) was highest, followed by CRF01_AE (34.84%), CRF55_01B (14.62%), B (6.06%), URFs (3.58%), CRF59_01B (2.17%) and other subtypes (0.63%). The annual proportions of subtype B (P=0.000, 99%CI:0.000-0.000), CRF07_BC (χ(2)=14.965, P=0.036), CRF55_01B (χ(2)=18.161, P=0.011) and URFs (P=0.001, 99% CI: 0.000-0.001) were significantly different. The proportion of subtype B showed a gradual decrease from 14.08% to 4.33% (P=0.000, 99%CI: 0.000-0.000), while the proportion of URFs rapidly increased from 0% to 6.40% (P=0.000, 99% CI: 0.000-0.000). The rate of URFs was significantly higher in farmers and migrant workers than in other groups (P=0.017, 99%CI: 0.014- 0.020) and the rate of URFs was higher in individuals who had multi sexual partners (χ(2)=5.733, P=0.017). Conclusions: CRF07_BC and CRF01_AE were the predominant HIV-1 subtypes and multiple subtypes co-circulated among MSM in Guangzhou between 2008 and 2015. The recombinations of HIV-1 continue to occur in MSM. Strengthening behavioral intervention for farmers, migrant workers and individuals who have multi sexual partners has the important epidemiological significance against the emerging and circulating of the novel recombinant virus among MSM in Guangzhou.

Prevalence of drug resistance in treatment-naive HIV infected men who have sex with men in Guangzhou, 2008-2015 / 中华流行病学杂志

Objective: To understand the prevalence of drug resistance in treatment-naive HIV infected men who have sex with (MSM) in Guangzhou. Methods: HIV-1 RNA were extracted from the serum specimens of the MSM newly confirmed to be HIV-1 positive, living in Guangzhou and receiving no anti-viral therapy from 2008 to 2015. HIV-1 pol gene segments, including full protease and part reverse transcriptase, were amplified by nested reverse transcription polymerase chain reaction (nested-PCR) and sequenced by Sanger. Subsequently, the sequence data were submitted to Stanford University HIV Drug Resistance Database for drug resistance analysis. Results: Among 2 283 HIV infected MSM, HIV-1 pol gene segments were obtained from the serum samples of 1 986 HIV infected MSM aged 16-84 (30.18±8.24) years. Among them, the unmarried accounted for 74.17% (1 473/1 986), those of Han ethnic group accounted for 90.64% (1 800/1 986), those with education level of college or above accounted for 49.65% (986/1 986), those with education level of senior high school or secondary school accounted for 27.14% (539/1 986), those with education level of junior high school or below accounted for 20.89% (415/1 986). The distribution of subtypes was predominated by CRF07_BC (38.22%, 759/1 986) and CRF01_AE (34.49%, 685/1 986). The overall prevalence of drug resistance was 3.32% (66/1 986). The prevalence of resistance to protease inhibitors (PIs), nucleoside reverse transcriptase inhibitors (NRTIs) and non-nucleoside reverse transcriptase inhibitors (NNRTIs) were 1.36%(27/1 986), 0.65% (13/1 986) and 1.61% (32/1 986), respectively. Subtype B had higher resistance to PIs, NRTIs and NNRTIs and subtype CRF55_01B had highest resistance to NNRTIs compared with other subtypes. In subtype B, the resistant rates to D4T, EFV and NVP were highest (all 4.17%, 5/120), followed by those to NFV, AZT and RPV (all 3.33%, 4/120). In subtype CRF55_01B, the resistant rates to EFV and NVP were highest (all 5.50%, 16/291), followed by those to ETR and RPV (all 5.15%, 15/291). Conclusions: The prevalence of drug resistance in treatment-naive HIV infected MSM in Guangzhou remained at low level and current antiretroviral drugs are generally effective. However, subtype B and CRF55_01B have higher drug resistance.