Characteristics and influencing factors regarding social relations among men who have sex with men / 中华流行病学杂志

Objective: To study the characteristics of social relations and relative factors among MSM in Guangzhou. Methods: Data was collected through a cross-sectional study in Guangzhou from November 2016 to May 2017. Sample size was estimated and participants were recruited from the voluntary counseling and testing services (VCT) which were set for MSM population, by nongovernmental organizations (NGOs) and the Centers for Disease Control and Prevention (CDC). Social ties and demographic characteristics of the respondents and their sexual partners were analyzed through both Chi square test and generalized estimating equations (GEE). Results: A total of 1 073 MSM, together with their nominated 4 301 partners were successfully recruited and involved in this study. Age (OR=1.2, P=0.01) and non-internet based intercourse (OR=1.65, P<0.01) were easy to form close relation with strong ties. Compared with MSM traditional venues (chess and cards room, tea room bathhouse, club), general public venue (bars, KTV, parks, shopping malls, schools, restaurants) (OR=1.46-3.12, P<0.01) showed close relation with strong ties. Our finding showed that MSM at the age of 18-25 preferred to build weak ties with the older MSM, while the 26-30-year-olds and 31-40-year-olds prefer to establish weak ties with younger partners but the 41-50-year-olds preferred to develop weak ties with one that were ten years younger. Conclusions: Clusters were noticed in the MSM populations when grouping and making friends with ones at different age. Characteristics regarding the relationship between sexual partners in choosing venues and ways of dating were different. Targeted intervention programs need to be explored innovatively.

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.