For gay, bisexual, and other sexual minority men (SMM), geo-social exposures in residential and non-residential places are important to consider for health, as home, social, sexual, substance use, and healthcare-related locations may be different. We use survey data from a sample of 219 Black and Hispanic SMM within Los Angeles County to examine the places that individuals visit for eight specific activities, categorized as either lifestyle or healthcare-related. Spatial clustering techniques are used to identify hotspots, or places where individual's activities are clustered in space, for each activity. We then use descriptive statistics to characterize each hotspot based on the socio-demographic characteristics of individuals who engaged in activities within the hotspot, and then assess whether activity-based hotspots overlap in space. We find unique spatial patterns of hotspots, distinct by activity. Additionally, lifestyle activity space hotspots are spatially patterned by socio-demographic characteristics, primarily along race and ethnic categories, whereas healthcare-related hotspots are not. The overlap, or spatial congruence of hotspots, is higher than we hypothesized, as hotspots of residential locations contained the majority of sex hotspots and substance use hotspots. Our work ultimately identifies four distinct areas of Los Angeles County in which activities are clustered among men in the sample, and health interventions can be tailored to the individuals and their activities in those places. Our findings demonstrate the importance of geographically and demographically targeted interventions, at a fine spatial scale, for health promotion among SMM, as interventions and policy to provide equitable care to reduce racial disparities in health among SMM are sorely needed.

BACKGROUND:The Ending the HIV Epidemic initiative in the United States relies on HIV hotspots to identify where to geographically target new resources, expertise, and technology. However, interventions targeted at places with high HIV transmission and infection risk, not just places with high HIV incidence, may be more effective at reducing HIV incidence and achieving health equity. OBJECTIVE:We described the implementation and validation of a web-based activity space survey on HIV risk behaviors. The survey was intended to collect geographic information that will be used to map risk behavior hotspots as well as the geography of sexual networks in Los Angeles County. METHODS:The survey design team developed a series of geospatial questions that follow a 3-level structure that becomes more geographically precise as participants move through the levels. The survey was validated through 9 cognitive interviews and iteratively updated based on participant feedback until the saturation of topics and technical issues was reached. RESULTS:In total, 4 themes were identified through the cognitive interviews: functionality of geospatial questions, representation and accessibility, privacy, and length and understanding of the survey. The ease of use for the geospatial questions was critical as many participants were not familiar with mapping software. The inclusion of well-known places, landmarks, and road networks was critical for ease of use. The addition of a Google Maps interface, which was familiar to many participants, aided in collecting accurate and precise location information. The geospatial questions increased the length of the survey and warranted the inclusion of features to simplify it and speed it up. Using nicknames to refer to previously entered geographic locations limited the number of geospatial questions that appeared in the survey and reduced the time taken to complete it. The long-standing relationship between participants and the research team improved comfort to disclose sensitive geographic information related to drug use and sex. Participants in the cognitive interviews highlighted how trust and inclusive and validating language in the survey alleviated concerns related to privacy and representation. CONCLUSIONS:This study provides promising results regarding the feasibility of using a web-based mapping survey to collect sensitive location information relevant to ending the HIV epidemic. Data collection at several geographic levels will allow for insights into spatial recall of behaviors as well as future sensitivity analysis of the spatial scale of hotspots and network characteristics. This design also promotes the privacy and comfort of participants who provide location information for sensitive topics. Key considerations for implementing this type of survey include trust from participants, community partners, or research teams to overcome concerns related to privacy and comfort. The implementation of similar surveys should consider local characteristics and knowledge when crafting the geospatial components.

Abstract Background HIV epidemic among men who have sex with men (MSM) remains a major public health concern in China. Despite a growing body of research on transgender women worldwide, little is known about Chinese transgender women within MSM. We sought to estimate HIV incidence and distinguish risk factors of HIV acquisition among them from that among cisgener (non-transgender) MSM (cis-MSM). Methods We conducted an open cohort study among Chinese MSM, including those who were identified as transgender in Shanghai and Tianjin. Participants were initially recruited by local community-based organizations from January to June, 2016, and were followed up approximately every 6 months until June 2018. At each visit, a structured questionnaire was used to gather information on demographics, sexual risk behaviors, and HIV status. HIV incidence was calculated as the number of seroconversions divided by total number of person-years of follow-up among HIV-negatives at baseline. Risk factors of HIV acquisition were assessed by univariate and multivariate Cox regression models with time-dependent variables. Results A total of 1056 participants contributed 1260.53 person-years (PYs) of follow-up, 33 HIV seroconversions occurred during the follow-up period, yielding an estimated HIV incidence of 2.62 (95% CI 1.80–3.68) per 100 PYs. HIV incidence among transgender women was 4.42 per 100 PYs, which was significantly higher than that of 1.35 per 100 PYs among cis-MSM, demonstrating a threefold higher odds of HIV infection than cis-MSM. For transgender women, those lived locally ≤ 2 years (adjusted hazard ratio [aHR] = 1.76, 95% CI 1.13–2.76) and unprotected anal sex last time (aHR = 4.22, 95% CI 1.82–9.79) were more likely to acquire HIV. For cis-MSM, factors associated with HIV acquisition were frequency of anal sex ≥ 3 times in past one month (aHR = 4.19, 95% CI 1.06–16.47) and unprotected anal sex last time (aHR = 5.33, 95% CI 1.52–18.73). Conclusions Compared to cis-MSM, transgender women were at higher risk of HIV acquisition, highlighting an urgent need of tailored prevention. Future HIV program should consider to include them to ensure that this population in China are not left behind. Graphical abstract

Background: In the past ten years, men who have sex with men (MSM) has become one of the most important high-risk population of HIV in China. However, there is sparse research on the role of subgroups of MSM in driving the HIV epidemic. This study aims to compare HIV incidence among different subgroups of MSM and explore potential risk factors associated with HIV infection. This is the first prospective cohort study that estimates HIV incidence and behavioral risk factors among transgender and substance-using MSM in China. Methods: In this prospective cohort study, we recruited MSM aged 18 years and above with a history of oral or anal sex in the past six months. Baseline and follow-up visits were completed in Shenlan Public Health Consulting Service Center in Tianjin. The observation period for the cohort was 18 months, with check-ins occurring at six-month intervals. During each visit, participants were asked to fill out a structured questionnaire and free HIV and syphilis tests were provided. The questionnaire covered information on demographics, risk sexual behaviors, and substance use. Cumulative incidence of HIV and syphilis infection were estimated by Kaplan-Meier methods. The risk factors of HIV acquisition was analyzed by Cox regression models with time-dependent variables. We used a descriptive model to calculate odds ratios between predictive factors to reflect their positions in the causal pathway to HIV acquisition. Findings: From January 2016 to July 2018, 1079 MSM were recruited and 1005 were tested HIV negative at baseline. Among them, 885 participated in the follow-up at least twice and entered the cohort. The overall retention rate was 88·1% (885/1005). Compared with general MSM, transgender and substance-using MSM had much higher frequencies of oral or anal sex and higher proportions of inconsistent condom use. Among transgender MSM, over a half (56·1%, 142/253) used drugs, and the most commonly used drug was amyl nitrite (141/142, 99·3%). Compared with not using amyl nitrite, 90·8% (128/141) reported to have increased libido and 94·3% (133/141) had heightened sexual pleasure after using it. The incidence of HIV acquisition among transgender, substance-using and general MSM was 2·36 (95%CI: 1·18, 4·72), 1·75 (95%CI: 0·79, 3·89) and 1·68 (95%CI: 0·80, 3·52) per 100 PYs, respectively. Non-local residency (adjusted HR=3·23, 95%CI: 1·37, 7·64), inconsistent condom use (adjusted HR=22·40, 95%CI: 7·43, 67·54) and without regular sexual partner (adjusted HR= 4·56, 95%CI: 1·81, 11·49) were independent risk factors for HIV seroconversion. Interpretation: There were heightened HIV risks and incidence rates among transgender and substance-using MSM, comparing with general MSM. These two subgroups require intensive HIV epidemic surveillance and strengthened behavior prevention. Among MSM in Tianjin, those without local residency, without regular sexual partners, and inconsistent condom use played important roles in driving the HIV epidemic. Future stronger HIV prevention strategies for MSM should be implemented, in particular targeting those non-local and without stable partners.Funding Statement: M.A.C AIDS Fund (grant number: A-P-15-20660)Declaration of Interests: The authors declare no competing interests.Ethics Approval Statement: The study received approval from the institutional review board (IRB) of the National Center for AIDS/STD Control & Prevention, Chinese CDC (Approval number: X160729420). Subjects were provided written informed consent and were given a unique identification number in order to protect participants’ privacy.

The prevalence of human immunodeficiency virus (HIV) infection in China is low overall (0.06%) (1); however, it is substantially higher (8.0%) among men who have sex with men (MSM) (2), and the stigmatization of same-sex behaviors in China presents challenges for HIV prevention and treatment efforts. In 2015, Blued, a Beijing-based media company that operates an online dating application popular among Chinese MSM, launched an ongoing HIV testing campaign that combined its push-notification† platform and geolocation capabilities to encourage HIV testing among MSM in Beijing. To assess trends in use of HIV testing services, Blued and CDC's China HIV program examined testing at six Blued-operated Beijing HIV testing centers from 2 years before the campaign launch in 2015 through December 31, 2017. A sharp increase in HIV testing followed the launch of Blued's online campaign, indicating that leveraging social media platforms and their geolocation-based text messaging functionality might be useful in increasing HIV testing among MSM, particularly those aged ≤35 years.

Biomedical ontologies are envisioned to be useable in a range of research and clinical applications. The requirements for such uses include formal consistency, adequacy of coverage, and possibly other domain specific constraints. In this report we describe a case study that illustrates how application specific requirements may be used to identify modeling problems as well as data entry errors in ontology building and evolution. We have begun a project to use the UW Foundational Model of Anatomy (FMA) in a clinical application in radiation therapy planning. This application focuses mainly (but not exclusively) on the representation of the lymphatic system in the FMA, in order to predict the spread of tumor cells to regional metastatic sites. This application requires that the downstream relations associated with lymphatic system components must only be to other lymphatic chains or vessels, must be at the appropriate level of granularity, and that every path through the lymphatic system must terminate at one of the two well known trunks of the lymphatic system. It is possible through a programmable query interface to the FMA to write small programs that systematically audit the FMA for compliance with these constraints. We report on the design of some of these programs, and the results we obtained by applying them to the lymphatic system. The algorithms and approach are generalizable to other network organ systems in the FMA such as arteries and veins. In addition to illustrating exact constraint checking methods, this work illustrates how the details of an application may reflect back a requirement to revise the design of the ontology itself.