Sex networking of young men who have sex with men in densely connected saunas in Hong Kong.

BACKGROUND: Some men who have sex with men (MSM) meet and have sex with male partners at gay saunas, the connections between which are little explored for designing HIV prevention measures. This study aims to describe the network configuration of gay saunas and explore its relationship with risk behavior of MSM in the respective sauna communities, in the city of Hong Kong. METHODS: Using venue-based sampling, 205 MSM were recruited in 8 saunas in July 2011 for a cross-sectional anonymous questionnaire survey. A network of saunas was constructed based on the proportion of clients shared between them. Core saunas with higher intensity of linkages were delineated from core-periphery analysis. Men who have sex with men in core saunas were compared with those in peripheral ones in terms of their demographics and risk behavioral profiles. RESULTS: Eight core saunas were differentiated from a highly connected sauna network, consisting of 13 saunas with a diameter of 2. Men who have sex with men visiting core saunas were more likely to be younger and users of the Internet for sex networking (odds ratio, 5.43; 95% confidence interval, 1.84-16.01). On average, they visited 1.7 saunas and had 2.6 sauna partners over a 1-month period, which were both significantly higher than those for MSM in peripheral saunas. However, there was no association between having unprotected anal sex and visiting core saunas. Sauna affiliation patterns were age dependent and geographically related. CONCLUSIONS: Saunas were not homogeneously connected with each other. Prioritization may be considered so that public health interventions can be targeted at saunas in denser networks. An assortative mixing in age among MSM in sauna community informs planning for client-specific venue-based prevention programs.

Virtual versus physical channel for sex networking in men having sex with men of sauna customers in the City of Hong Kong.

BACKGROUND: Advances in communication technology may affect networking pattern, thereby influencing the dynamics of sex partnership. The aim of the study is to explore the impacts of partner sourcing through internet and related channels on exposure risk to sexually transmitted infections (STI) including HIV. METHODS: Using venue-based sampling, a cross-sectional questionnaire survey was conducted at saunas frequented by men having sex with men (MSM) in Hong Kong. Comparison was made between MSM sourcing partners through physical venues alone versus concomitant users of physical and virtual channels, the latter referring to internet and smart-phone applications, using bivariate logistic regression. RESULTS: Over a 7-week study period, 299 MSM were recruited from 9 saunas. Three main types of sex partners were distinguished: steady (46.8%), regular (26.4%) and casual (96.0%) partners. Users of sauna (n = 78) were compared with concomitant users of saunas and virtual channels (n = 179) for partner sourcing. Sauna-visiting virtual channel users were younger and inclined to use selected physical venues for sourcing partners. Smart-phone users (n = 90) were not different from other internet-users in terms of age, education level and single/mixed self-identified body appearance. Classifying respondents into high risk and low risk MSM by their frequency of condom use, concomitant use of both sauna and virtual channels accounted for a higher proportion in the high risk category (71.6% vs. 58.2%, OR = 1.81, p<0.05). In virtual channel users, partner sourcing through smart-phone was not associated with a higher practice of unprotected sex. CONCLUSION: MSM sauna customers commonly use virtual channels for sex partner sourcing. Unprotected sex is more prevalent in sauna customers who use virtual channel for sex partner sourcing. While the popularity of smart-phone is rising, its use is not associated with increased behavioural risk for HIV/STI transmission.

Impact of the herbal medicine Sophora flavescens on the oral pharmacokinetics of indinavir in rats: the involvement of CYP3A and P-glycoprotein.

Sophora flavescens is a Chinese medicinal herb used for the treatment of gastrointestinal hemorrhage, skin diseases, pyretic stranguria and viral hepatitis. In this study the herb-drug interactions between S. flavescens and indinavir, a protease inhibitor for HIV treatment, were evaluated in rats. Concomitant oral administration of Sophora extract (0.158 g/kg or 0.63 g/kg, p.o.) and indinavir (40 mg/kg, p.o.) in rats twice a day for 7 days resulted in a dose-dependent decrease of plasma indinavir concentrations, with 55%-83% decrease in AUC(0-∞) and 38%-78% reduction in C(max). The CL (Clearance)/F (fraction of dose available in the systemic circulation) increased up to 7.4-fold in Sophora-treated rats. Oxymatrine treatment (45 mg/kg, p.o.) also decreased indinavir concentrations, while the ethyl acetate fraction of Sophora extract had no effect. Urinary indinavir (24-h) was reduced, while the fraction of indinavir in faeces was increased after Sophora treatment. Compared to the controls, multiple dosing of Sophora extract elevated both mRNA and protein levels of P-gp in the small intestine and liver. In addition, Sophora treatment increased intestinal and hepatic mRNA expression of CYP3A1, but had less effect on CYP3A2 expression. Although protein levels of CYP3A1 and CYP3A2 were not altered by Sophora treatment, hepatic CYP3A activity increased in the Sophora-treated rats. All available data demonstrated that Sophora flavescens reduced plasma indinavir concentration after multiple concomitant doses, possibly through hepatic CYP3A activity and induction of intestinal and hepatic P-gp. The animal study would be useful for predicting potential interactions between natural products and oral pharmaceutics and understanding the mechanisms prior to human studies. Results in the current study suggest that patients using indinavir might be cautioned in the use of S. flavescens extract or Sophora-derived products.

An exploratory study on the social and genotypic clustering of HIV infection in men having sex with men.

OBJECTIVE: To explore the clustering of HIV infected men having sex with men (MSM) using social network approach in conjunction with the phylogenetic relationship of the virus strains. DESIGN: An exploratory study incorporating social network and phylogenetic analysis. METHODS: Recently diagnosed HIV-infected MSM attending one major HIV specialist clinic in Hong Kong were recruited in the study involving the administration of a self-administered questionnaire on behaviours and partnership patterns using a Likert Scale, the results of which were assessed using social network analysis and in context of the phylogenetic analysis from sequencing the HIV-1 pol gene, as part of the clinical investigation for genotypic resistance. Clusters were defined using social and molecular methods. RESULTS: An 'Internet-centred' cluster and 'Sauna-centred' cluster could be delineated using correspondence analysis and network diagrams. The main distinguishing features of MSM in the 'Internet-centred' social cluster were: younger age, higher education level, and multiple partner types. Three genetic clusters could be identified in the phylogenetic tree, two of which associated with Internet use and one with sauna for sex partnership. There were partial overlaps between social and genetic clusters. Characteristically, the virus strains in sauna users were more disperse compared with the closely knit configuration of those using Internet. CONCLUSION: The principle of the duality of place and person can be strategically applied in epidemiologic investigation. The characterization of MSM cluster using anonymized network data provides a potentially powerful tool for informing public health intervention.

Popular use of traditional Chinese medicine in HIV patients in the HAART era.

Seventy-six Chinese male HIV patients were interviewed on their use of traditional Chinese medicine (TCM). All except one had undetectable viral load, 28 had already progressed to AIDS. Forty-five (59.2%) had used TCM--11 infrequently and 33 commonly. No specific TCM recipe was preferentially used, while a variety of herbal tea and other over-the-counter health products of TCM in origin were reported. A minority (28.9%) have consulted a TCM practitioner in the preceding 6 months. Most patients admitted using TCM for the treatment of minor ailments (60.0%) and general health maintenance (57.8%), while western medicine was chosen for the therapy of major medical illnesses. TCM did not seem to have significant influence on the conventional HAART in this cohort. Many used TCM at a time interval from HAART in order not to affect the latter's effectiveness.