ORIGINAL STUDY

Sex Networking of Young Men Who Have Sex With Men in Densely Connected Saunas in Hong Kong Chin Man Poon, BSSc and Shui Shan Lee, MD 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, 1.84Y16.01). 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.

interpreted in context of one’s social networks. Their associations with sexual behavior could be useful in explaining the transmission dynamics of sexually transmitted infections (STIs) among MSM.7Y10 It has long been known that sex networking of MSM takes place in social venues, the patterns of which could shed light on the transmission potential of HIV and other STIs. Specifically, gay saunas or bathhouses provide MSM with a social space for meeting and having sex with one’s male partners.11 They have long been known to be important social venues, where investigators sample MSM for epidemiological studies.12,13 On the other hand, public health interventions have been developed that targeted gay saunas because the latter were reported to be associated with higher risk of transmitting HIV or STIs.14Y16 Some MSM might visit more than one sauna. These would become the bridges between MSM from different saunas. In this sense, saunas are networked, allowing the spread of HIV or STIs across their client bases. So far, little has been done in incorporating information on network affiliations for designing public health interventions, although its importance at gay saunas has been acknowledged.17Y21 An understanding of the association between risk behaviors of MSM and their mobility patterns between saunas at various network positions, if any, would be helpful to inform future planning of prevention strategies. Against this background, a study was conceptualized to describe the network configurations of gay saunas in Hong Kong. The potential of transmission of STIs was also differentiated by evaluating risk behaviors of MSM based on their affiliated networked saunas.

I

n the past decade, rising incidence of human immunodeficiency virus (HIV) infection was observed among men who have sex with men (MSM) in Hong Kong and other parts of the world.1Y4 Homosexual contact has become the most common route of transmission for newly reported HIV infection cases in Hong Kong since 2009.1 In this connection, prevalence of sexual risk behavior, including unprotected anal sex, engagement in casual sex, and concurrent sexual relationships, has been examined for evaluating the risk of HIV transmission among Chinese MSM.5,6 These individual characteristics should be From the Stanley Ho Centre for Emerging Infectious Diseases, The Chinese University of Hong Kong, Hong Kong, China

This study is supported by General Research Fund, No. 470110, from Research Grants Council of Hong Kong, China. Data of this manuscript were analyzed by different approaches and presented in Eighth UKSNA Conference, Bristol, UK, and Seventh IAS Conference on HIV Pathogenesis, Treatment and Prevention 2013, Kuala Lumpur, Malaysia. Conflict of interest: None. Correspondence: Shui Shan Lee, MD, Postgraduate Education Centre, Prince of Wales Hospital, Room 205, Shatin, NT, Hong Kong, China. E-mail: [email protected]. Received for publication June 7, 2013, and accepted September 23, 2013. DOI: 10.1097/OLQ.0000000000000052 Copyright * 2013 American Sexually Transmitted Diseases Association All rights reserved.

Sexually Transmitted Diseases

&

MATERIALS AND METHODS This is a cross-sectional study for examining the sexnetworking patterns of MSM and their associated risk behaviors in Hong Kong. Data were collected through a questionnaire administered at saunas patronized by MSM. Sex-networking patterns were characterized through a series of network analyses.

Study Participants Venue-based sampling was adopted for participant recruitment among MSM, which was regarded as one of the known hard-to-reach populations.22 A preliminary list of saunas and venue, day-time units with estimated number and characteristics of clients was synthesized through mapping. Identification of gay saunas was made through focus group discussions and review of published materials, including venue lists from previous prevalence studies, and advertisement on gay Websites and magazines. Of 20 identified saunas, 8 were accessed for conducting the study. The remaining saunas were excluded either because of refusal of owners or because of the very low estimated number of (G4) potential participants per venue, day-time unit. In this study, the target number of MSM to be recruited was 200. Eligible participants for the study were male adults 18 years or older who (a) could speak Chinese, (b) self-admitted to have

Volume 40, Number 12, December 2013

933

Copyright © 2013 by the American Sexually Transmitted Diseases Association. Unauthorized reproduction of this article is prohibited.

Poon and Lee

had history of sex with male partner(s), and (c) consented to participating in the study. Two trained male volunteers approached MSM whomever they could meet at the saunas and invited them to participate in a self-administered anonymous questionnaire survey. A tablet computer embedded with the questionnaire was presented to invited participants who could complete the survey by themselves within 5 to 10 minutes in the common area of the saunas. An incentive of HK$20 (US$2.5) was offered to respondents after completion of the survey. Ethical

TABLE 1.

approval was obtained from the Survey and Behavioural Research Ethics Committee of The Chinese University of Hong Kong.

Measures The questionnaire was constructed in Chinese language. Respondents were queried about their channels for seeking sex partners in the preceding month. These channels included specific saunas and other types of physical or virtual venues, the latter referring to the Internet. A list of saunas was provided in

Characteristics of Recruited MSM (n = 205)

Characteristics

No. (%) of MSM in Core Saunas

n (%)

Age, y e20 21Y25 26Y30 31Y40 940 Education level Secondary school or below Tertiary education or above Socioeconomic status Currently employed/self-employed Students Others Residence region Hong Kong Island Kowloon New Territories West New Territories East Frequency for sauna visit (missing = 9) Biweekly/Monthly Weekly or more often Using alternative channels, other than sauna, for sex networking (n = 201) Other physical venues‡ Internet§ Not using any alternative channels Having lovers/regular partners¶ Have had unprotected anal sex Always use a condom for anal sex No anal sex/unknown Have had unprotected oral sex Always use a condom for oral sex No oral sex/Unknown Having casual partners¶ Have had unprotected anal sex Always use a condom for anal sex No anal sex/Unknown Have had unprotected oral sex Always use a condom for oral sex No oral sex/unknown Having commercial partners¶ Have had unprotected anal sex Always use a condom for anal sex No anal sex/unknown Have had unprotected oral sex Always use a condom for oral sex No oral sex/unknown

22 58 49 45 31

OR (95% CI)

(10.7) (28.3) (23.9) (22.0) (15.1)

16 (72.7) 46 (79.3) 42 (85.7) 26 (57.8) 5 (16.1)

83 (40.5) 122 (59.5)

53 (63.9) 82 (67.2)

V 1.14 (0.63Y2.07)

150 (73.2) 35 (17.1) 20 (9.8)

95 (63.3) 29 (82.9) 11 (55.0)

1.49 (0.58Y3.84) 4.75 (1.30Y17.32)† V

(23.4) (38.5) (21.0) (17.1)

34 (70.8) 51 (64.6) 27 (62.8) 23 (65.7)

V 0.64 (0.29Y1.44) 0.64 (0.26Y1.58) 0.74 (0.28Y1.96)

92 (46.9) 104 (53.1)

56 (60.9) 76 (73.1)

V 1.74 (0.96Y3.19)

20 (10.0) 39 (19.4) 155 (77.1) 63 (30.7) 34 (54.0) 21 (33.3) 8 (12.7) 52 (82.5) 2 (3.2) 9 (14.3) 120 (58.5) 30 (25.0) 65 (54.2) 25 (20.8) 100 (83.3) 10 (8.3) 10 (8.3) 5 (2.4) 0 (0.0) 4 (80.0) 1 (20.0) 3 (60.0) 0 (0.0) 2 (40.0)

16 (80.0) 35 (89.7) 92 (59.4) 43 (68.3) 24 (70.6) 14 (66.7) 5 (62.5) 36 (69.2) 0 (0.0) 7 (77.7) 79 (65.8) 22 (73.3) 47 (72.3) 10 (40.0) 66 (66.0) 7 (70.0) 6 (60.0) 4 (80.0) 0 (0.0) 4 (100.0) 0 (0.0) 3 (100.0) 0 (0.0) 1 (50.0)

4.30 5.43 0.18 1.35 1.12||

48 79 43 35

16.64 19.93 36.40 7.95

1.10|| 1.04 1.71|| 0.77|| 1.98

(4.16Y66.62)* (6.32Y62.88)* (10.08Y131.40)* (2.55Y24.76)* V

(0.96Y19.30) (1.84Y16.01)* (0.07Y0.47)* (0.70Y2.61) (0.36Y3.46) V V (0.25Y4.87) V V (0.57Y1.89) (0.66Y4.45) V V (0.25Y2.34) V V (0.22Y18.12) V V V V V V

G 0.01. †P G 0.05. physical venues include public toilets, bars, sex parties and dance parties. Internet refers to all virtual venues, including chat-room, instant messaging program, Websites and mobile phone applications. ¶ Lovers were sex partners that respondents considered to be emotionally attached to and in a stable relationship; regular partners were those with sexual relationship alone over extended periods; casual partners were typically one-night-stand partners without emotional attachment nor extended relationship; commercial partners were those with sexual relationship maintained by exchange of money or other rewards. All respondents reported whether they had particular type of partners. || Adjusted for having respective type of partners. *P

‡ Other §

934

Sexually Transmitted Diseases

&

Volume 40, Number 12, December 2013

Copyright © 2013 by the American Sexually Transmitted Diseases Association. Unauthorized reproduction of this article is prohibited.

Networked Saunas in MSM Community

the questionnaire to give participants prompting cues for sauna selection. They were also asked to report the number of sex partners in the previous month. Sex partners were classified into lovers, regular partners, casual partners, and commercial partners, taking reference from the framework used in previous studies on HIV positive MSM (Table 1, footnote).18 Behavioral profiles were assessed by type of sex partners, focusing on their practice of anal and oral sex as well as use of condom. Demographic information including age, education level, socioeconomic status, and residence district was collected at the end of the questionnaire.

Analysis On the premise that saunas sharing same clients are closer to one another, matrices can be drawn to describe the social relationship among saunas. Ties between saunas were, therefore, established by MSM visiting 2 or more saunas in the past month. Strength of relationship between 2 saunas was defined by a ratio of the number of MSM attending the saunas to the total number of MSM visiting the 2 saunas over a 1-month period. Saunas with fewer than 5 clients were excluded in the network analysis for reducing the chance of having biased value in strength of relationship. Spatial relationship among saunas was expressed in another matrix. Two saunas were considered to be networked if they were located within a certain distance. Cohesion of the network was measured by network density, which was defined as the average strength of ties across all possible ties. Normalized degree centrality of each sauna was calculated as a fraction of the number of saunas in connection over all possible ties. Hypothesizing that saunas sharing their clients were located closely with one another, measure of association between the relations in social and spatial matrices of

saunas was calculated. Quadratic assignment procedures were used to estimate standard errors for testing for the significance of this association.23 Core/Periphery analysis was used to separate the saunas into 2 blocks of high and low intragroup density respectively. Johnson’s hierarchical clustering was applied separately to identify equivalence classes and visualize the degree of similarity among saunas, which was derived from the average strength of ties in each cluster.24 All network analyses were conducted in UCINET 6 for Windows (Analytic Technologies, Harvard, MA), and network visualization was performed by using NetDraw 2.113 (Analytic Technologies, Lexington, KY).23 The differences in demographics and risk behavioral profiles between MSM in core and peripheral saunas were assessed and compared. All statistical analyses were conducted with PASW Statistics 18 (SPSS Inc, Chicago, IL). Differences were classified as being statistically significant when a P value was less than 0.05.

RESULTS Characteristics of Respondents In a 1-month period in July 2011, 24 visits were made at the convenience of the sauna owners, leading to the recruitment of 205 MSM. Of these, 201 claimed to have sought male partners in saunas as their primary means for sex networking over the preceding month. More than half were aged between 21 and 30 years and had attained tertiary education or above. Three quarters of the respondents were employed or self-employed at the time of the survey (Table 1). One in 5 had used the Internet as alternative channel for sex networking. Thirty-eight MSM

Figure 1. Sauna network for MSM community in Hong Kong. Each node denotes a gay sauna patronized by MSM, with size adjusted by the observed number of sauna clients and thickness of ties referring their strength. Positions of the saunas are determined by their networking relationship between other saunas without consideration of their geographic information. Sampling of MSM took place in saunas represented by square nodes. Box in dashed line indicates the group of core saunas. Sexually Transmitted Diseases

&

Volume 40, Number 12, December 2013

935

Copyright © 2013 by the American Sexually Transmitted Diseases Association. Unauthorized reproduction of this article is prohibited.

Poon and Lee

(18.5%) admitted having both lovers/regular partners and casual partners in the past month. Unprotected anal sex was twice as common with lovers or regular partners (54.0%) than that with casual partners (25.0%). A total of 5 respondents (2.4%) reported having been involved in commercial sex, but none had unprotected anal sex. Regardless of the type of sex partners, less than 10% had used condom for every act of oral sex (Table 1).

Overview of Sauna Network To describe the configuration of the network of saunas connected by MSM, 13 saunas patronized by more than 5 study participants were included in network analysis. Of 78 possible ties between saunas, 51 (two thirds) were noted in the survey. The proportion of clients shared between 2 saunas ranged between 1.0% and 26.5% of the total number of MSM going to either sauna. As displayed in the network diagram, the saunas were networked with a density of 0.0383 (Fig. 1). The network gave a diameter of 2, implying that it is possible for an MSM to reach any other MSM in saunas within 2 steps. Normalized degree centrality of saunas ranged from 0.33 to 0.92, indicating that a sauna might be socially linked to 3 to 11 other saunas by MSM. Results of quadratic assignment procedure test showed that 2 saunas were more likely to be connected with each other, given that they were within 1 km apart (P G 0.05).

Subcommunities of Sauna-Recruited MSM From the sauna network configuration, core/periphery analysis yielded a core group of 8 saunas with an intragroup density of 0.073. The remaining 5 saunas were at peripheral positions with an intragroup density of 0.037. Smaller clusters of saunas within both core and peripheral groups were differentiated by conducting cluster analysis (Fig. 2). There were 135 (65.9%) and 80 (39.0%) MSM visiting core and peripheral saunas, respectively. Of 75 MSM (36.6%) who visited more than 1 sauna, 14 went to both core and peripheral saunas. Over a 1-month period, MSM in core saunas, on average, visited 1.70 saunas, whereas those only patronizing peripheral saunas visited 1.23 saunas (mean difference, 0.48; P G 0.001). The mean number of male sex partners networked by MSM visiting core

Figure 2. Dendrogram generated from cluster analysis. The dendrogram displays the results obtained by agglomerative hierarchical clustering. The length of branches represents the reverse of average strength of ties among saunas in each newly formed cluster. The dashed line separates saunas into 2 broad categoriesVcore saunas and peripheral saunas.

936

saunas was 2.6, which was also significantly higher than that for MSM visiting peripheral saunas only (mean difference, 0.93; P = 0.011). However, there was no significant difference in the frequency of sauna visits between MSM in core and peripheral saunas (odds ratio [OR], 1.74; 95% confidence interval [CI], 0.96Y3.19). Compared with MSM visiting peripheral sauna(s) only, MSM in core saunas were more likely to be younger, students (OR, 4.75; 95% CI, 1.30Y17.32) and users of the Internet for sex networking (OR, 5.43; 95% CI, 1.84Y16.01) (Table 1). Men who have sex with men visiting core saunas also tended to use other physical venues for sex networking (OR, 4.30; 95% CI, 0.96Y19.30; P = 0.057) such as bars, public toilets, or party venues. However, MSM having unprotected sex with lovers/ regular partners or casual partners was not associated with visiting core saunas.

DISCUSSION This is one of the few studies that have characterized the sexual relationship among MSM using a network of sexual affiliations with a focus on venues for seeking sex partners.17Y21 Our analyses on the sauna networks offered a novel perspective for differentiating MSM into characteristic subcommunities and their association with risky sexual behavior. In our study, we were able to distinguish between 2 broad categories of saunas where sex networking occurredVcore saunas and peripheral saunas. Core saunas were characterized by a higher intragroup density, which implied a higher flow of clients among them. Men who have sex with men in core saunas had a higher number of sexual partners and more frequent connections with other social venues. Given the denser and larger network of core saunas, their clients would be more likely to transmit STIs among MSM who were actively involved in sex networking in saunas, whenever unprotected sex was practiced.25,26 Young and computer-literate MSM were the major networking members of core saunas, whereas older MSM were associated with relatively loosely connected peripheral saunas. The latter phenomenon was in line with the observed isolation from mainstream gay culture among old MSM in another study.27 Both observations suggested assortative mixing in age among MSM in sauna community, which was probably driven by the social environment of sexual affiliations. Although having sex with older partners has been reported to be associated with HIV infection since 1990s, assortativity in age observed in this study might imply a reduced exposure to HIV among young MSM in sauna community.7 Another finding of this study is that geographic location of a sauna was associated with the establishment of social links to other saunas. Proximity between saunas implied a similar accessibility for their clients and hence an increased likelihood of sharing the same group of clients. Added to the previously found association between social and geographic distance among urban persons at risk for HIV, our study shows the feasibility of inferring both distance from saunas instead of individuals.28 Geographic linkages of saunas could be one of the explanations for the enhanced connectivity between some MSM, an observation that supports the transmission of STIs. Furthermore, it was noted that approximately one fifth of our respondents reported concurrent sexual relationship(s) with regular and casual partners. Such phenomenon underlines the vulnerability of MSM to STIs by the introduction of more transmission pathways between sauna-visiting MSM and the community.29

Sexually Transmitted Diseases

&

Volume 40, Number 12, December 2013

Copyright © 2013 by the American Sexually Transmitted Diseases Association. Unauthorized reproduction of this article is prohibited.

Networked Saunas in MSM Community

Methodologically, our study empirically demonstrated the possibility of characterizing sexual structure of MSM by using 2-mode network data, which involved relations among a set of actors and a series of events.30 By using the data about the venues where MSM sought their partners, a network of sexual affiliation could be constructed for estimating sexual contact patterns. Study participants did not need to expose the identity of their sex partners or recall each and every of their partners. Therefore, public health investigators could overcome difficulties in data collection arising from partner naming and occasional forgetfulness. Knowingly, the sauna network derived from 2-mode network data does not equate actual sexual network. To assess the transmission dynamics of HIV or STIs among MSM through this approach, probability for sexual contact for each MSM in each sauna has to be determined in future studies. This study carries some limitations. First, sauna owners had the authority to decide the visit period for sampling MSM. Recruitment of respondents was simply impossible because of refusal of owners in some saunas, implying that connections between these venues could have been underestimated. On the other hand, the connections between a sampled venue and a nonsampled venue might be overestimated. Excluding venues with low observed number of clients in the analysis might also introduce bias in the network configuration, although 4 of these 7 excluded saunas had actually closed down subsequently. The size and cohesion of the entire MSM network might also be influenced because other social venues frequented by MSM were not included, especially those virtual channels for sex networking. While the Internet allowed MSM to seek sex partners with little space-time limit, it is anticipated that the actual sexual affiliation network would be much denser than what we observed at physical venues. Further assessment would be required for evaluating the effect on overall sexual contact patterns after incorporating other types of social venue in sexual affiliation networks. Second, data collected in the questionnaire were prone to recall and social desirability bias, whereas the questions asked for one’s previous sexual behavior. Overall, this cross-sectional study provides a snapshot of the network of gay saunas but did not evaluate longitudinal changes of the use of different sex-networking venues, which would be important to assess HIV transmission dynamics. In conclusion, our study results suggest a highly connected and geographically related sauna network. A core group of saunas was patronized by young MSM who were assortatively mixed in age in this community. These findings suggest that public health interventions should be targeted at some core saunas, which were densely connected to each other, for effective use of resources. An assessment of client characteristics, including their sex-networking patterns, would also be important to inform client-specific HIV or STI prevention program implemented at saunas.

REFERENCES 1. Centre for Health Protection, Department of Health. Hong Kong STD/AIDS Update Vol.18 No.4, Quarter 4V2012 [Virtual AIDS Office of Hong Kong]. 3 April, 2013. Available at: http://www. info.gov.hk/aids/english/surveillance/stdaids/std12q4.pdf. Accessed May 14, 2013. 2. Chow EP, Wilson DP, Zhang J, et al. Human immunodeficiency virus prevalence is increasing among men who have sex with men in China: Findings from a review and meta-analysis. Sex Transm Dis 2011; 38:845Y857.

Sexually Transmitted Diseases

&

3. Sullivan PS, Hamouda O, Delpech V, et al. Reemergence of the HIV epidemic among men who have sex with men in North America, Western Europe, and Australia, 1996Y2005. Ann Epidemiol 2009; 19:423Y431. 4. Beyrer C, Baral SD, van Griensven F, et al. Global epidemiology of HIV infection in men who have sex with men. Lancet 2012; 380:367Y377. 5. Liu H, Yang H, Li X, et al. Men who have sex with men and human immunodeficiency virus/sexually transmitted disease control in China. Sex Transm Dis 2006; 33:68Y76. 6. Guo Y, Li X, Stanton B. HIV-related behavioral studies of men who have sex with men in China: A systematic review and recommendations for future research. AIDS Behav 2011; 15:521Y534. 7. Morris M, Zavisca J, Dean L. Social and sexual networks: Their role in the spread of HIV/AIDS among young gay men. AIDS Educ Prev 1995; 7(5 suppl):24Y35. 8. Smith AM, Grierson J, Wain D, et al. Associations between the sexual behaviour of men who have sex with men and the structure and composition of their social networks. Sex Transm Infect 2004; 80:455Y458. 9. Luke DA, Harris JK. Network analysis in public health: history, methods, and applications. Annu Rev Public Health 2007; 28: 69Y93. 10. Drumright LN, Frost SD. Rapid social network assessment for predicting HIV and STI risk among men attending bars and clubs in San Diego, California. Sex Transm Infect 2010; 86(suppl 3): iii17Yiii23. 11. Tattelman I. Speaking to the gay bath house: Communicating in sexually charged spaces. In: Leap W, ed. Public Sex/Gay Space. New York: Columbia University Press, 1999:71Y94. 12. Bingham TA, Secura GM, Behel SK, et al. HIV risk factors reported by two samples of male bathhouse attendees in Los Angeles, California, 2001Y2002. Sex Transm Dis 2008; 35:631Y636. 13. Lee SS, Lam AN, Lee CK, et al. Virtual versus physical channel for sex networking in men having sex with men of sauna customers in the City of Hong Kong. PLoS One 2012; 7:e31072. 14. Ko NY, Lee HC, Hung CC, et al. Effects of structural intervention on increasing condom availability and reducing risky sexual behaviours in gay bathhouse attendees. AIDS Care 2009; 21: 1499Y1507. 15. Huebner DM, Binson D, Pollack LM, et al. Implementing bathhousebased voluntary counselling and testing has no adverse effect on bathhouse patronage among men who have sex with men. Int J STD AIDS 2012; 23:182Y184. 16. Lau JT, Lin C, Hao C, et al. Public health challenges of the emerging HIV epidemic among men who have sex with men in China. Public Health 2011; 125:260Y265. 17. Frost SD. Using sexual affiliation networks to describe the sexual structure of a population. Sex Transm Infect 2007;83(suppl 1): i37Yi42. 18. Lee SS, Tam DK, Tan Y, et al. An exploratory study on the social and genotypic clustering of HIV infection in men having sex with men. AIDS 2009;23:1755Y1764. 19. Lee SS, Tam DK, Ho RL, et al. Social network methodology for studying HIV epidemiology in men having sex with men. J Infect Public Health 2009;2:177Y183. 20. Oster AM, Wejnert C, Mena LA, et al. Network analysis among HIV-infected young black men who have sex with men demonstrates high connectedness around few venues. Sex Transm Dis 2013;40:206Y212. 21. Fujimoto K, Williams ML, Ross MW. Venue-based affiliation networks and HIV risk-taking behavior among male sex workers. Sex Transm Dis 2013; 40:453Y458. 22. Muhib FB, Lin LS, Stueve A, et al. A venue-based method for sampling hard-to-reach populations. Public Health Rep 2001; 116(suppl 1):216Y222. 23. Borgatti SP, Everett MG, Freeman LC. UCINET for Windows: Software for Social Network Analysis. Harvard, MA: Analytic Technologies, 2002. 24. Hanneman RA, Riddle M. Introduction to Social Network Methods. Riverside, CA: University of California, Riverside, 2005.

Volume 40, Number 12, December 2013

937

Copyright © 2013 by the American Sexually Transmitted Diseases Association. Unauthorized reproduction of this article is prohibited.

Poon and Lee

25. Friedman SR, Neaigus A, Jose B, et al. Sociometric risk networks and risk for HIV infection. Am J Public Health 1997; 87:1289Y1296. 26. Doherty IA, Padian NS, Marlow C, et al. Determinants and consequences of sexual networks as they affect the spread of sexually transmitted infections. J Infect Dis 2005; 191(suppl 1):S42YS54. 27. Ramello S. Same sex acts involving older men. An ethnographic study. J Aging Stud 2013; 27:121Y134.

938

28. Rothenberg R, Muth SQ, Malone S, et al. Social and geographic distance in HIV risk. Sex Transm Dis 2005; 32:506Y512. 29. Morris M, Kretzschmar M. Concurrent partnerships and the spread of HIV. AIDS 1997; 11:641Y648. 30. Hawe P, Webster C, Shiell A. A glossary of terms for navigating the field of social network analysis. J Epidemiol Community Health 2004; 58:971Y975.

Sexually Transmitted Diseases

&

Volume 40, Number 12, December 2013

Copyright © 2013 by the American Sexually Transmitted Diseases Association. Unauthorized reproduction of this article is prohibited.

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

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 designi...
896KB Sizes 0 Downloads 0 Views