The Geography of Heterosexual Partnerships in Baltimore City Adults

Novel Location-Based Survey Using Cognitive Interviews to Assess Geographic Networks and Hotspots of Sex and Drug Use: Implementation and Validation Study

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.

Evaluating the sensitivity of jurisdictional heterogeneity and jurisdictional mixing in national level HIV prevention analyses: context of the U.S. ending the HIV epidemic plan

BACKGROUND

The U.S. Ending the HIV epidemic (EHE) plan aims to reduce annual HIV incidence by 90% by 2030, by first focusing interventions on 57 regions (EHE jurisdictions) that contributed to more than 50% of annual HIV diagnoses. Mathematical models that project HIV incidence evaluate the impact of interventions and inform intervention decisions. However, current models are either national level, which do not consider jurisdictional heterogeneity, or independent jurisdiction-specific, which do not consider cross jurisdictional interactions. Data suggests that a significant proportion of persons have sexual partnerships outside their own jurisdiction. However, the sensitivity of these jurisdictional interactions on model outcomes and intervention decisions hasn't been studied.

METHODS

We developed an ordinary differential equations based compartmental model to generate national-level projections of HIV in the U.S., through dynamic simulations of 96 epidemiological sub-models representing 54 EHE and 42 non-EHE jurisdictions. A Bernoulli equation modeled HIV-transmissions using a mixing matrix to simulate sexual partnerships within and outside jurisdictions. To evaluate sensitivity of jurisdictional interactions on model outputs, we analyzed 16 scenarios, combinations of a) proportion of sexual partnerships mixing outside jurisdiction: no-mixing, low-level-mixing-within-state, high-level-mixing-within-state, or high-level-mixing-within-and-outside-state; b) jurisdictional heterogeneity in care and demographics: homogenous or heterogeneous; and c) intervention assumptions for 2019-2030: baseline or EHE-plan (diagnose, treat, and prevent).

RESULTS

Change in incidence in mixing compared to no-mixing scenarios varied by EHE and non-EHE jurisdictions and aggregation-level. When assuming jurisdictional heterogeneity and baseline-intervention, the change in aggregated incidence ranged from - 2 to 0% for EHE and 5 to 21% for non-EHE, but within each jurisdiction it ranged from - 31 to 46% for EHE and - 18 to 109% for non-EHE. Thus, incidence estimates were sensitive to jurisdictional mixing more at the jurisdictional level. As a result, jurisdiction-specific HIV-testing intervals inferred from the model to achieve the EHE-plan were also sensitive, e.g., when no-mixing scenarios suggested testing every 1 year (or 3 years), the three mixing-levels suggested testing every 0.8 to 1.2 years, 0.6 to 1.5 years, and 0.6 to 1.5 years, respectively (or 2.6 to 3.5 years, 2 to 4.8 years, and 2.2 to 4.1 years, respectively). Similar patterns were observed when assuming jurisdictional homogeneity, however, change in incidence in mixing compared to no-mixing scenarios were high even in aggregated incidence.

CONCLUSIONS

Accounting jurisdictional mixing and heterogeneity could improve model-based analyses.

A Systematic Review of Neighborhood-Level Influences on HIV Vulnerability

A better understanding of the social-structural factors that influence HIV vulnerability is crucial to achieve the goal of ending the HIV epidemic by 2030. Given the role of neighborhoods in HIV outcomes, synthesis of findings from such research is key to inform efforts toward HIV eradication. We conducted a systematic review to examine the relationship between neighborhood-level factors (e.g., poverty) and HIV vulnerability (via sexual behaviors and substance use). We searched six electronic databases for studies published from January 1, 2007 through November 30, 2017 (PROSPERO CRD42018084384). We also mapped the studies' geographic distribution to determine whether they aligned with high HIV prevalence areas and/or the "Ending the HIV Epidemic: A Plan for the United States". Fifty-five articles met inclusion criteria. Neighborhood disadvantage, whether measured objectively or subjectively, is one of the most robust correlates of HIV vulnerability. Tests of associations more consistently documented a relationship between neighborhood-level factors and drug use than sexual risk behaviors. There was limited geographic distribution of the studies, with a paucity of research in several counties and states where HIV incidence/prevalence is a concern. Neighborhood influences on HIV vulnerability are the consequence of centuries-old laws, policies and practices that maintain racialized inequities (e.g., racial residential segregation, inequitable urban housing policies). We will not eradicate HIV without multi-level, neighborhood-based approaches to undo these injustices. Our findings inform future research, interventions and policies.

Social-spatial network structures and community ties of egocentric sex and confidant networks: A Chicago case study

Exploring how sexual and confidant networks overlap spatially and socially could facilitate a better understanding of sexually transmitted infection risk, as well as help identify areas for interventions. This study aims to examine how a sexual and peer-affiliate network is impacted or shaped by interconnected social relationships and spatial patterns. We used data collected from a sample of 618 young black men who have sex with men (YBMSM) and transgender women in Chicago (2013-2014) that includes partner and confidant links, geolocations, and pre-exposure prophylaxis (PrEP) awareness. We spatialize different types of social networks and examine joint social-spatial community ties to both identify and differentiate social-spatial behavioral patterns. We explore the spatial structures of the social network by comparing ego-alter network residence patterns, visualizing ego-alter community ties in aggregate, and grouping different types of dyad relationships based on their spatial structure. Findings showed overlapping social and sexual networks. Egos with partners residing in more resourced communities furthest away, with wider alter-ego power differentials, also tended to be at greatest risk. Identifying the social-spatial structures of community ties is critical to enhance our understanding of the spatial context of social relationships, and further distill risk heterogeneity in vulnerable populations within an equitable health framework.

Geographic Distribution of HIV Transmission Networks in the United States

BACKGROUND

Understanding geographic patterns of HIV transmission is critical to designing effective interventions. We characterized geographic proximity by transmission risk and urban-rural characteristics among people with closely related HIV strains suggestive of potential transmission relationships.

METHODS

We analyzed US National HIV Surveillance System data of people diagnosed between 2010 and 2016 with a reported HIV-1 partial polymerase nucleotide sequence. We used HIV TRAnsmission Cluster Engine (HIV-TRACE) to identify sequences linked at a genetic distance of ≤0.5%. For each linked person, we assessed median distances between counties of residence at diagnosis by transmission category and urban-rural classification, weighting observations to account for persons with multiple linked sequences.

RESULTS

There were 24,743 persons with viral sequence linkages to at least one other person included in this analysis. Overall, half (50.9%) of persons with linked viral sequences resided in different counties, and the median distance from persons with linked viruses was 11 km/7 miles [interquartile range (IQR), 0-145 km/90 miles]. Median distances were highest for men who have sex with men (MSM: 14 km/9 miles; IQR, 0-179 km/111 miles) and MSM who inject drugs, and median distances increased with increasing rurality (large central metro: 0 km/miles; IQR, 0-83 km/52 miles; nonmetro: 103 km/64 miles; IQR, 40 km/25 miles-316 km/196 miles).

CONCLUSION

Transmission networks in the United States involving MSM, MSM who inject drugs, or persons living in small metro and nonmetro counties may be more geographically dispersed, highlighting the importance of coordinated health department efforts for comprehensive follow-up and linkage to care.

Neighborhood and Network Characteristics and the HIV Care Continuum among Gay, Bisexual, and Other Men Who Have Sex with Men

In order for treatment as prevention to work as a national strategy to contain the HIV/AIDS epidemic in the United States (US), the HIV care continuum must become more robust, retaining more individuals at each step. The majority of people living with HIV/AIDS (PLWHA) in the US are gay, bisexual, and other men who have sex with men (MSM). Within this population, there are distinct race- and ethnicity-based disparities in rates of HIV infection, engagement, and retention in HIV care, and viral suppression. Compared with White MSM, HIV-infected Black MSM are less likely to be on anti-retroviral therapy (ART), adhere to ART, and achieve viral suppression. Among MSM living in urban areas, falling off the continuum may be influenced by factors beyond the individual level, with new research identifying key roles for network- and neighborhood-level characteristics. To inform multi-level and multi-component interventions, particularly to support Black MSM living in urban areas, a clearer understanding of the pathways of influence among factors at various levels of the social ecology is required. Here, we review and apply the empirical literature and relevant theoretical perspectives to develop a series of potential pathways of influence that may be further evaluated. Results of research based on these pathways may provide insights into the design of interventions, urban planning efforts, and assessments of program implementation, resulting in increased retention in care, ART adherence, and viral suppression among urban-dwelling, HIV-infected MSM.

The Social Geography of Partner Selection in Toronto, Canada: A Qualitative Description of "Convection Mixing"

The geographic distribution of sexually transmitted infections reflects the underlying social process of sexual partner selection. This qualitative study explored the social geography of partner selection among sexual minority men and used the results to develop a mid-range theory of STI transmission. In-depth interviews with 31 sexual minority men who lived, worked, or socialized in Toronto, Canada, occurred in June and July 2016. Participants were asked how they found sexual partners and reconstructed their egocentric sexual networks for the previous 3 months. Participants described an iterative process of partner selection involving intention (sex versus dating), connecting with community, and selecting a partner based on intersecting partner characteristics (external, internal, and emergent feelings when interacting with potential partners) and personal preferences. Geography influenced partner selection three ways: (1) participant search patterns maximized the number of potential partners in the shortest distance possible; (2) the density of sexual minority men in a participant's community directly impacted participant's social and sexual isolations; and (3) geosexual isolation influenced sexual mixing patterns. Participants described "convection mixing," where assortative urban mixing nested within disassortative suburban mixing resulted in movement from the suburbs to downtown and back to the suburbs. We theorize that convection mixing may be contributing to the persistence of STI epidemics in core and outbreak areas by creating STI reservoirs outside of, and connected to, core and outbreak areas.

Exploring spatially varying demographic associations with gonorrhea incidence in Baltimore, Maryland, 2002-2005

The ability to establish spatial links between gonorrhea risk and demographic features is an important step in disease awareness and more effective prevention techniques. Past spatial analyses focused on local variations in risk, but not on spatial variations in associations with demographics. We collected data from the Baltimore City Health Department from 2002 to 2005 and evaluated demographic features known to be associated with gonorrhea risk in Baltimore, by allowing spatial variation in associations using Poisson geographically weighted regression (PGWR). The PGWR maps revealed variations in local relationships between race, education, and poverty with gonorrhea risk which were not captured previously. We determined that the PGWR model provided a significantly better fit to the data and yields a more nuanced interpretation of "core areas" of risk. The PGWR model's quantification of spatial variation in associations between disease risk and demographic features provides local and demographic structure to core areas of higher risk.

Mortgage Discrimination and Racial/Ethnic Concentration Are Associated with Same-Race/Ethnicity Partnering among People Who Inject Drugs in 19 US Cities

Racial/ethnic homophily in sexual partnerships (partners share the same race/ethnicity) has been associated with racial/ethnic disparities in HIV. Structural racism may partly determine racial/ethnic homophily in sexual partnerships. This study estimated associations of racial/ethnic concentration and mortgage discrimination against Black and Latino residents with racial/ethnic homophily in sexual partnerships among 7847 people who inject drugs (PWID) recruited from 19 US cities to participate in CDC's National HIV Behavioral Surveillance. Racial/ethnic concentration was defined by two measures that respectively compared ZIP code-level concentrations of Black residents to White residents and Latino residents to White residents, using the Index of Concentration at the Extremes. Mortgage discrimination was defined by two measures that respectively compared county-level mortgage loan denial among Black applicants to White applicants and mortgage loan denial among Latino applicants to White applicants, with similar characteristics (e.g., income, loan amount). Multilevel logistic regression models were used to estimate associations. Interactions of race/ethnicity with measures of racial/ethnic concentration and mortgage discrimination were added to the final multivariable model and decomposed into race/ethnicity-specific estimates. In the final multivariable model, among Black PWID, living in ZIP codes with higher concentrations of Black vs. White residents and counties with higher mortgage discrimination against Black residents was associated with higher odds of homophily. Living in counties with higher mortgage discrimination against Latino residents was associated with lower odds of homophily among Black PWID. Among Latino PWID, living in ZIP codes with higher concentrations of Latino vs. White residents and counties with higher mortgage discrimination against Latino residents was associated with higher odds of homophily. Living in counties with higher mortgage discrimination against Black residents was associated with lower odds of homophily among Latino PWID. Among White PWID, living in ZIP codes with higher concentrations of Black or Latino residents vs. White residents was associated with lower odds of homophily, but living in counties with higher mortgage discrimination against Black residents was associated with higher odds of homophily. Racial/ethnic segregation may partly drive same race/ethnicity sexual partnering among PWID. Future empirical evidence linking these associations directly or indirectly (via place-level mediators) to HIV/STI transmission will determine how eliminating discriminatory housing policies impact HIV/STI transmission.

Conceptualizing Geosexual Archetypes: Mapping the Sexual Travels and Egocentric Sexual Networks of Gay and Bisexual Men in Toronto, Canada

Six geosexual archetypes were identified: hosters, house-callers, rovers, privates, travellers, and geoflexibles, each with different characteristic profiles. Prioritizing interventions to hosters, rovers, and geoflexibles may reduce sexually transmitted infection transmission.

Supplemental digital content is available in the text.

Background

There are complex, synergistic, and persistent sexually transmitted infection (STI) epidemics affecting gay, bisexual and other men who have sex with men (gbMSM) in every major urban centre across North America. We explored the spatial architecture of egocentric sexual networks for gbMSM in Toronto, Canada.

Methods

Our integrative mixed methods study included in-depth interviews with 31 gbMSM between May and July 2016. During interviews, participants mapped their egocentric sexual network for the preceding 3 months geographically. At the end, a self-administered survey was used to collect sociodemographic characteristics, online technology use, and STI testing and history.

Results

We identified 6 geosexual archetypes: hosters, house-callers, privates, rovers, travellers, and geoflexibles. Hosters always, or almost always (≥80%), hosted sex at their home. House-callers always, or almost always (≥80%), had sex at their partner’s home. Rovers always or almost always (≥80%) had sex at public venues (eg, bath houses, sex clubs) and other public spaces (eg, parks, cruising sites). Privates had sex in private—their own home or their partner's (part hoster, part house-caller). Travellers had sex away from their home, either at a partner’s home or some other venue or public space (part house-caller, part rover). Geoflexibles had sex in a variety of locations—their home, their partner’s home, or public venues. All hosters and rovers, and to a lesser extent, geoflexibles, reported a history of syphilis and human immunodeficiency virus.

Conclusions

Prioritizing interventions to hosters, rovers, and geoflexibles may have an important impact on reducing STI transmission.

Knowledge and perceptions of Zika virus transmission in the community of Puerto Plata, Dominican Republic

Background

Zika virus is associated with increased cases of both microcephaly and Guillain-Barré syndrome. Community knowledge, perceptions and practices to prevent infection with the Zika virus are not well understood, particularly among high risk populations living in resource-poor and Zika-endemic areas. Our objective was to assess knowledge of symptoms, health effects and prevention practices associated with Zika virus in rural communities on the northern coast of the Dominican Republic.

Methods

Study participants were contacted while attending community events such as free medical clinics and invited to be interviewed regarding their knowledge, attitudes, and perceptions of Zika virus using the World Health Organization’s Zika survey tool.

Results

Of the 75 Dominicans that participated, 33% did not know who could become infected with Zika. In addition, only 40% of respondents were able to identify mosquitoes or sexual transmission as the primary routes of infection though 51% of respondents thought that Zika was an important issue in their community.

Conclusions

This study found that general knowledge regarding the basic risks and transmission of Zika were not well understood among a sample of rural Dominicans. Our findings highlight disparities in knowledge and perception of risk from Zika in rural areas compared to previous studies conducted in the Dominican Republic. Education about the basic risks and transmission of Zika are critically needed in these remote populations to reduce Zika transmission.

Applying core theory and spatial analysis to identify hepatitis C virus infection "core areas" in British Columbia, Canada

"Core areas" of transmission for bacterial sexually transmitted infections have been identified. However, it is unclear whether core areas apply to viral infections, such as hepatitis C virus (HCV). We used geographic mapping and spatial analysis to identify distinct core areas of HCV infection in British Columbia (BC) using the BC Hepatitis Testers Cohort (BC-HTC), 1990-2013. The BC-HTC includes all BC residents tested for HCV (~1.5 million; 1990-2013). Core HCV infection areas were identified spatially and temporally for five time periods (1990-1993, 1994-1998, 1999-2003, 2004-2008 and 2009-2013) through thematic mapping, Kernel Density Estimation, Hotspot analysis and cluster analysis at the Census dissemination area level in ArcGIS and SatScan. HCV infection core areas were consistently identified. HCV core areas expanded from the downtown of major cities in different regions of BC (Metro Vancouver, Vancouver Island, and Northern BC; 1990-1998), to smaller cities in Metro Vancouver and Interior BC (2000 onwards). Statistically significant clusters, or hotspots, were also observed for downtown Vancouver, Northern BC (Prince George) and Vancouver Island from 1990 to 2008 with expansion to other urban areas in Metro Vancouver from 1990-2013. Statistically significant clusters persisted after adjustment for injection drug use, number of HCV tests, age, sex, material and social deprivation. Persistence of areas with high HCV diagnoses rates in Vancouver and Prince George supports the theory of core areas of HCV transmission. Identification of core areas can inform prevention, care and treatment programme interventions and evaluate their impact over time.

Associations Between Neighborhood Characteristics, Social Cohesion, and Perceived Sex Partner Risk and Non-Monogamy Among HIV-Seropositive and HIV-Seronegative Women in the Southern U.S

Neighborhood social and physical factors shape sexual network characteristics in HIV-seronegative adults in the U.S. This multilevel analysis evaluated whether these relationships also exist in a predominantly HIV-seropositive cohort of women. This cross-sectional multilevel analysis included data from 734 women enrolled in the Women's Interagency HIV Study's sites in the U.S. South. Census tract-level contextual data captured socioeconomic disadvantage (e.g., tract poverty), number of alcohol outlets, and number of non-profits in the census tracts where women lived; participant-level data, including perceived neighborhood cohesion, were gathered via survey. We used hierarchical generalized linear models to evaluate relationships between tract characteristics and two outcomes: perceived main sex partner risk level (e.g., partner substance use) and perceived main sex partner non-monogamy. We tested whether these relationships varied by women's HIV status. Greater tract-level socioeconomic disadvantage was associated with greater sex partner risk (OR 1.29, 95% CI 1.06-1.58) among HIV-seropositive women and less partner non-monogamy among HIV-seronegative women (OR 0.69, 95% CI 0.51-0.92). Perceived neighborhood trust and cohesion was associated with lower partner risk (OR 0.83, 95% CI 0.69-1.00) for HIV-seropositive and HIV-seronegative women. The tract-level number of alcohol outlets and non-profits were not associated with partner risk characteristics. Neighborhood characteristics are associated with perceived sex partner risk and non-monogamy among women in the South; these relationships vary by HIV status. Future studies should examine causal relationships and explore the pathways through which neighborhoods influence partner selection and risk characteristics.

Place Still Matters: Racial/Ethnic and Geographic Disparities in HIV Transmission and Disease Burden

Neighborhood-level structural interventions are needed to address HIV/AIDS in highly affected areas. To develop these interventions, we need a better understanding of contextual factors that drive the pandemic. We used multinomial logistic regression models to examine the relationship between census tract of current residence and mode of HIV transmission among HIV-positive cases. Compared to the predominantly white high HIV prevalence tract, both the predominantly black high and low HIV prevalence tracts had greater odds of transmission via injection drug use and heterosexual contact than male-to-male sexual contact. After adjusting for current age, gender, race/ethnicity, insurance status, and most recently recorded CD4 count, there was no statistically significant difference in mode of HIV transmission by census tract. However, heterosexual transmission and injection drug use remain key concerns for underserved populations. Blacks were seven times more likely than whites to have heterosexual versus male-to-male sexual contact. Those who had Medicaid or were uninsured (versus private insurance) were 23 and 14 times more likely, respectively, to have injection drug use than male-to-male sexual contact and 10 times more likely to have heterosexual contact than male-to-male sexual contact. These findings can inform larger studies for the development of neighborhood-level structural interventions.

Social determinants of adult sex ratios and racial/ethnic disparities in transmission of HIV and other sexually transmitted infections in the USA

In Black population centres in the USA, adult sex ratios (ASRs) are strongly female-biased primarily due to high male incarceration and early mortality rates. I explore the system of social determinants that shape these ASRs, and describe their apparent consequences. Evidence suggests that female-biased ASRs play a role, along with racial residential segregation, to increase mixing between core and peripheral members of sexual networks, facilitating transmission of human immunodeficiency virus and other sexually transmitted infections. Unique historical factors underlie Black male incarceration and mortality rates in the USA, making comparisons with other groups or other countries challenging.This article is part of the themed issue 'Adult sex ratios and reproductive decisions: a critical re-examination of sex differences in human and animal societies'.

Potential High-Risk Areas for Zika Virus Transmission in the Contiguous United States

OBJECTIVES

To understand where transmission of Zika virus has the highest likelihood to occur in the contiguous United States with regard to its transmission both sexually and via Aedes aegypti mosquito bites.

METHODS

We evaluated the 2 routes of transmission risk with predictors of sexually transmitted infections (percentage women of childbearing age, birthrate, gonorrhea and chlamydia rates, concentrated disadvantage) as a surrogate for unprotected sexual activity and the demographic distribution of the A. aegypti mosquito across 3108 counties in the contiguous United States.

RESULTS

We found that 507 counties had the highest risk of virus exposure via mosquito vector or unprotected sexual activity; these were concentrated in southern states extending northward along the Atlantic coast and southern California, with the highest predicted risk in Mississippi counties.

CONCLUSIONS

Identifying areas with higher transmission risk can inform prevention strategies and vector control, and assist in planning for diagnosis and treatment.

Associations between neighborhood characteristics and sexual risk behaviors among HIV-infected and HIV-uninfected women in the southern United States

PURPOSE

Neighborhood characteristics shape sexual risk in HIV-uninfected adults in the United States (US). We assess relationships between census tract characteristics and sexual risk behaviors in a predominantly HIV-infected cohort of women living in the Southern US.

METHODS

This cross-sectional multilevel analysis included data from 737 HIV-infected and HIV-uninfected women enrolled in the Women's Interagency HIV Study. Administrative data captured characteristics of census tracts where women lived; participant-level data were gathered via survey. We used principal components analysis to condense tract-level variables into components: social disorder (e.g., violent crime rate), and social disadvantage (e.g., alcohol outlet density). We used hierarchical generalized linear models to assess relationships between tract-level characteristics and condomless vaginal intercourse, anal intercourse, and condomless anal intercourse.

RESULTS

Greater social disorder was associated with less anal intercourse (OR = 0.63, 95% CI = 0.43-0.94) and condomless anal intercourse (OR = 0.49, 95% CI = 0.30-0.80), regardless of HIV status. There were no statistically significant additive or multiplicative interactions between tract characteristics and HIV status.

CONCLUSIONS

Neighborhood characteristics are associated with sexual risk behaviors among women living in the Southern US, these relationships do not vary by HIV status. Future studies should establish temporality and explore the causal pathways through which neighborhoods influence sexual risk.

Public Housing Relocations and Partnership Dynamics in Areas With High Prevalences of Sexually Transmitted Infections

BACKGROUND

We investigated the implications of one structural intervention--public housing relocations--for partnership dynamics among individuals living areas with high sexually transmitted infection (STI) prevalence. High-prevalence areas fuel STI endemicity and are perpetuated by spatially assortative partnerships.

METHODS

We analyzed 7 waves of data from a cohort of black adults (n = 172) relocating from 7 public housing complexes in Atlanta, Georgia. At each wave, data on whether participants' sexual partners lived in the neighborhood were gathered via survey. Participant addresses were geocoded to census tracts, and measures of tract-level STI prevalence, socioeconomic conditions, and other attributes were created for each wave. "High-prevalence tracts" were tracts in the highest quartile of STI prevalence in Georgia. Descriptive statistics and hierarchical generalized linear models examined trajectories of spatially assortative partnerships and identified predictors of assortativity among participants in high-prevalence tracts.

RESULTS

All 7 tracts containing public housing complexes at baseline were high-prevalence tracts; most participants relocated to high-prevalence tracts. Spatially assortative partnerships had a U-shaped distribution: the mean percent of partners living in participants' neighborhoods at baseline was 54%; this mean declined to 28% at wave 2 and was 45% at wave 7. Participants who experienced greater postrelocation improvements in tract-level socioeconomic conditions had a lower odds of having spatially assortative partnerships (adjusted odds ratio, 1.55; 95% confidence interval [95% CI], 1.06-2.26).

CONCLUSIONS

Public housing relocation initiatives may disrupt high-prevalence areas if residents experience significant postrelocation gains in tract-level socioeconomic conditions.

Geographic Variation in Condom Availability and Accessibility

Identifying predictors that contribute to geographic disparities in sexually transmitted infections (STIs) is necessary in order to reduce disparities. This study assesses the spatial relationship condom availability and accessibility in order to better identify determinants of geographic disparities in STIs. We conducted a telephone-based audit among potential-condom selling establishments. Descriptive analyses were conducted to detect differences in condom-selling characteristics by stores and by store type. Geocoding, mapping, and spatial analysis were conducted to measure the availability of condoms. A total of 850 potential condom-selling establishments participated in the condom availability and accessibility audit in St. Louis city; 29 % sold condoms. There were several significant geographic clusters of stores identified across the study area. The first consisted of fewer convenience stores and gas stations that sold condoms in the northern section of the city, whereas condoms were less likely to be sold in non-convenience store settings in the southwestern and central parts of the city. Additionally, locations that distributed free condoms clustered significantly in city center. However, there was a dearth of businesses that were neither convenience stores nor gas stations in the northern region of the city, which also had the highest concentration of condoms sold. This initial study was conducted to provide evidence that condom availability and accessibility differ by geographic region, and likely are a determinant of social norms surrounding condom use and ultimately impact STI rates.

Male Incarceration Rates and Rates of Sexually Transmitted Infections: Results From a Longitudinal Analysis in a Southeastern US City

BACKGROUND

In the United States, rates of certain sexually transmitted infections (STIs) are increasing. Contextual factors seem to play an important role in shaping STI transmission dynamics. This longitudinal study explores the relationship between one contextual determinant of health (the male incarceration rate) and rates of newly diagnosed STIs in census tracts in Atlanta, GA.

METHODS

The sample consisted of all census tracts in Atlanta (n = 946). Annual data on STI diagnoses were drawn from the Georgia surveillance system for 2005 to 2010; annual male incarceration data were drawn from the Georgia Department of Corrections for 2005 to 2010; and data on potential confounders were drawn from the US Census. Multivariable growth models were used to examine the association between the male incarceration rate and rates of newly diagnosed STIs, controlling for covariates.

RESULTS

Census tracts with higher baseline male incarceration rates had a higher baseline rate of newly diagnosed STIs. Census tracts with increasing male incarceration rates experienced a more rapid increase in their rate of newly diagnosed STIs. Census tracts with medium and high baseline male incarceration rates experienced a decrease in their rate of newly diagnosed STIs over time.

CONCLUSIONS

The present study strengthens the evidence that male incarceration rates have negative consequences on sexual health outcomes, although the relationship may be more nuanced than originally thought. Future multilevel research should explore individual sexual risk behaviors and networks in the context of high male incarceration rates to better understand how male incarceration shapes rates of STIs.

Condom deserts: geographical disparities in condom availability and their relationship with rates of sexually transmitted infections

BACKGROUND

Identifying predictors that contribute to geographical disparities in sexually transmitted infections (STIs) is necessary. This study assesses the spatial relationship between condom availability to locations of STIs in order to better understand these geographical disparities.

OBJECTIVES

We conducted a condom availability audit among potential condom-selling establishments. New gonorrhoea and chlamydia cases in 2011 (n=6034) and HIV infection cases from 2006 to 2011 (n=565) were collected by census tract in St Louis, Missouri. 829 potential condom-selling establishments participated in the condom availability audit in St Louis City; 242 of which sold condoms.

RESULTS

A negative linear relationship exists between condom vendors and cases of gonorrhoea and chlamydia, after adjusting for concentrated disadvantage and free condom locations. Higher concentrated disadvantage, higher proportions of convenience vendors and free locations were associated with higher rates of HIV.

CONCLUSIONS

This study was conducted to provide evidence that lack of condom availability is associated with STI rates, and likely is an integral component to influencing the subjective norms surrounding condom use and STI rates. Condom distribution interventions may be addressing availability needs and social norms, yet are more likely to be effective when placed in locations with the highest STI rates.

Changes in Exposure to Neighborhood Characteristics are Associated with Sexual Network Characteristics in a Cohort of Adults Relocating from Public Housing

Ecologic and cross-sectional multilevel analyses suggest that characteristics of the places where people live influence their vulnerability to HIV and other sexually-transmitted infections (STIs). Using data from a predominately substance-misusing cohort of African-American adults relocating from US public housing complexes, this multilevel longitudinal study tested the hypothesis that participants who experienced greater post-relocation improvements in economic disadvantage, violent crime, and male:female sex ratios would experience greater reductions in perceived partner risk and in the odds of having a partner who had another partner (i.e., indirect concurrency). Baseline data were collected from 172 public housing residents before relocations occurred; three waves of post-relocation data were collected every 9 months. Participants who experienced greater improvements in community violence and in economic conditions experienced greater reductions in partner risk. Reduced community violence was associated with reduced indirect concurrency. Structural interventions that decrease exposure to violence and economic disadvantage may reduce vulnerability to HIV/STIs.

Neighborhood Condition and Geographic Locale in Assessing HIV/STI Risk Among African American Adolescents

Although region and neighborhood condition's effect on HIV/sexually transmitted infection (STI) risk has been studied separately, there is little research examining their interplay. African American adolescents (n = 1,602) from four matched cities in the Northeastern and Southeastern US completed Audio Computer Assisted Self-Interviews and submitted biospecimen samples to detect Sexually Transmitted Infections (chlamydia, gonorrhea, and trichomonas). Logistic and negative binomial regressions determined HIV/STI risk differences by region, neighborhood stress, and stress-region dyads. Northeastern participants demonstrated lower HIV/STI risk while participants from higher stress neighborhoods exhibited greater risk. Relationships between neighborhood condition and ever having anal sex (p < 0.01), anal condom use (p < 0.05), and number of anal partners (p < 0.05) were significant in the Northeast only. Participants in unstressed Northeastern neighborhoods were less likely to have vaginal sex than those in comparable Southeastern neighborhoods (p < 0.05). Participants in unfavorable Northeastern neighborhoods had fewer anal partners than participants in comparable Southeastern neighborhoods (p < 0.01). In concert, neighborhood and region differentially affect HIV/STI risk.

HIV Sexual Risk and Syndemics among Women in Three Urban Areas in the United States: Analysis from HVTN 906

Limited data are available on the longitudinal occurrence of syndemic factors among women at risk for HIV infection in the USA and how these factors relate to sexual risk over time. HVTN 906 was a longitudinal study enrolling 799 HIV-uninfected women in three cities. Assessments were done at baseline, 6, 12, and 18 months to assess syndemic factors (low education, low income, unemployment, lack of health insurance, housing instability, substance use, heavy alcohol use, partner violence, incarceration) and sexual risk outcomes. For each sexual risk outcome, a GEE model was fit with syndemic factors or syndemic score (defined as sum of binary syndemics, ranging from 0 to 9), visit, study site, age and race/ethnicity as predictors to examine the multivariable association between syndemic factors and outcomes over time. Odds of unprotected sex while drunk or high were significantly higher when women reported lack of health insurance, substance and heavy alcohol use and partner violence. Housing instability, substance and heavy alcohol use, partner violence and recent incarceration were associated with higher odds of having multiple sexual partners. Odds of sex exchange were significantly higher in the presence of unemployment, housing instability, low education, lack of health insurance, substance and heavy alcohol use, partner violence and incarceration. Housing instability, substance and heavy alcohol use, and partner violence were significantly associated with higher odds of unprotected anal sex. Odds of having a recent STI were significantly higher when women reported housing instability and partner violence. There were significantly higher odds of the reporting of any risk outcomes during follow-up with higher syndemic score. This study highlights a group of women experiencing multiple poor social and health outcomes who need to be the focus of comprehensive interventions.

Impact of public housing relocations: are changes in neighborhood conditions related to STIs among relocaters?

BACKGROUND

Cross-sectional and ecologic studies suggest that place characteristics influence sexual behaviors and sexually transmitted infections (STIs). Using data from a predominately substance-misusing cohort of African American adults relocating from US public housing complexes, this multilevel longitudinal study tested the hypothesis that participants who experienced greater postrelocation improvements in neighborhood conditions (i.e., socioeconomic disadvantage, social disorder, STI prevalence, and male/female sex ratios) would have reduced the odds of testing positive for an STI over time.

METHODS

Baseline data were collected in 2009 from 172 public housing residents before relocations occurred; 3 waves of postrelocation data were collected every 9 months thereafter. Polymerase chain reaction methods were used to test participants' urine for Chlamydia trachomatis, Neisseria gonorrhoeae, and Trichomonas vaginalis. Individual-level characteristics were assessed via survey. Administrative data described the census tracts where participants lived at each wave (e.g., sex ratios, violent crime rates, and poverty rates). Hypotheses were tested using multilevel models.

RESULTS

Participants experienced improvements in all tract-level conditions studied and reductions in STIs over time (baseline: 29% tested STI positive; wave 4: 16% tested positive). Analyses identified a borderline statistically significant relationship between moving to tracts with more equitable sex ratios and reduced odds of testing positive for an STI (odds ratio, 0.16; 95% confidence interval, 0.02-1.01). Changes in other neighborhood conditions were not associated with this outcome.

DISCUSSION

Consonant with past research, our findings suggest that moving to areas with more equitable sex ratios reduces the risk of STI infection. Future research should study the extent to which this relationship is mediated by changes in sexual network dynamics.

Mapping U.S. long-haul truck drivers' multiplex networks and risk topography in inner-city neighborhoods

This article illustrates how urban inner-city trucking milieux may influence STI/BBI/HIV acquisition and transmission risks for U.S. long-haul truckers, as well as their social and risk relationships. Using mixed methods, we collected ethnoepidemiological and biological data from long-haul truck drivers and their risk contacts in inner-city trucking milieux in Atlanta, Georgia, United States. Key findings indicate that within the risk-endemic environment of distressed inner-city areas, diverse trucking risk milieux can amplify STI/BBI/HIV risk for multiplex networks of truckers. Inner-city neighborhood location, short geographic distance among risk contacts, and trucker concurrency can potentially exacerbate transmission via bridging higher-risk individuals with lower-risk populations at disparate geographic and epidemiological locations.

HIV prevalence overall and among high-HIV-risk behaviorally defined subgroups among heterosexuals at community-based venues in a Mid-Atlantic, US City

A clear understanding of local transmission dynamics is a prerequisite for the design and implementation of successful HIV prevention programs. There is a tremendous need for such programs geared towards young African-American women living in American cities with syndemic HIV and injection drug use. In some of these American cities, including Baltimore, the HIV prevalence rate among young African-American women is comparable to that in some African nations. High-risk heterosexual sex, i.e., sex with an injection drug user or sex with someone known to have HIV, is the leading risk factor for these young women. Characterizing transmission dynamics among heterosexuals has been hampered by difficulty in identifying HIV cases in these settings. The case identification method described in this paper was designed to address challenges encountered by previous researchers, was based on the Priorities for Local AIDS Cases methodology, and was intended to identify a high number of HIV cases rather than achieve a representative sample (Weir et al., Sex Transm Infect 80(Suppl 2):ii63-8, 2004. Through a three-phase process, 87 venues characterized as heterosexual sex partner meeting sites were selected for participant recruitment in Baltimore, MD. One thousand six hundred forty-one participants were then recruited at these 87 venues, administered a behavioral risk questionnaire, and tested for HIV. The HIV prevalence was 3 % overall, 3 % among males, and 4 % among females and ranged from 1.7 to 22.6 % among high-HIV-risk subgroups. These findings indicate that attributing HIV transmission to high-risk heterosexual sex vs. other high-HIV-risk behaviors would be difficult. Moving beyond individual risk profiles to characterize the risk profile of venues visited by heterosexuals at high risk of HIV acquisition may reveal targets for HIV transmission prevention and should be the focus of future investigations.

Neighborhoods and HIV: a social ecological approach to prevention and care

Neighborhood factors have been linked to HIV risk behaviors, HIV counseling and testing, and HIV medical care. However, the social-psychological mechanisms that connect neighborhood factors to HIV-related behaviors have not been fully determined. In this article we review the research on neighborhood factors and HIV-related behaviors, approaches to measuring neighborhoods, and mechanisms that may help to explain how the physical and social environment within neighborhoods may lead to HIV-related behaviors. We then discuss organizational, geographic, and social network approaches to intervening in neighborhoods to reduce HIV transmission and facilitate HIV medical care with the goal of reducing morbidity and mortality and increasing social and psychological well-being.

Does core area theory apply to sexually transmitted diseases in rural environments?

BACKGROUND

Our objective was to determine the extent to which geographical core areas for gonorrhea and syphilis are located in rural areas as compared with urban areas.

METHODS

Incident gonorrhea (January 1, 2005-December 31, 2010) and syphilis (January 1, 1999-December 31, 2010) rates were estimated and mapped by census tract and quarter. Rurality was measured using percent rural and rural-urban commuting area (rural, small town, micropolitan, or urban). SaTScan was used to identify spatiotemporal clusters of significantly elevated rates of infection. Clusters lasting 5 years or longer were considered core areas; clusters of shorter duration were considered outbreaks. Clusters were overlaid on maps of rurality and qualitatively assessed for correlation.

RESULTS

Twenty gonorrhea core areas were identified: 65% were in urban centers, 25% were in micropolitan areas, and the remaining 10% were geographically large capturing combinations of urban, micropolitan, small town, and rural environments. Ten syphilis core areas were identified with 80% in urban centers and 20% capturing 2 or more rural-urban commuting areas. All 10 (100%) of the syphilis core areas overlapped with gonorrhea core areas.

CONCLUSIONS

Gonorrhea and syphilis rates were high for rural parts of North Carolina; however, no core areas were identified exclusively for small towns or rural areas. The main pathway of rural sexually transmitted disease (STI) transmission may be through the interconnectedness of urban, micropolitan, small town, and rural areas. Directly addressing STIs in urban and micropolitan communities may also indirectly help address STI rates in rural and small town communities.

Concurrent sexual partnerships among urban African American high-risk women with main sex partners

To determine correlates of concurrent sexual partnerships among high-risk low-income urban African American women, survey responses of 337 women who had main sexual partners for over 6 months and reported high-risk behaviors were analyzed; 142 of these women also reported other sexual partnerships within the past 90 days. Unadjusted analyses showed that concurrency was significantly associated with relationship status, sexual debut, forced sex, incarceration of self and partners, depression, drug use, known or suspected partner nonmonogamy, and partner drug use. Age of sexual debut, relationship status, and indicators of problem drug use remained significantly associated with concurrency when controlling for individual factors, and only indicators of problem drug use and known or suspected partner nonmonogamy remained significantly associated with concurrency when also controlling for partner characteristics. Our results suggest the presence of extensive sexual networks within this population and document the need for interventions that address drug abuse and partnership instability. Moreover, the strong association between concurrency and perceptions of partners' nonmonogamy suggest the need for intervention to target men and women in this core group.

Sexually transmitted disease core theory: roles of person, place, and time

The authors' purpose was to expand sexually transmitted disease core theory by examining the roles of person, place, and time in differentiating geographic core areas from outbreak areas. The authors mapped yearly census-tract-level syphilis rates for San Francisco, California, based on new primary and secondary syphilis cases reported to the San Francisco City sexually transmitted disease surveillance program between January 1, 1985, and December 31, 2007. SaTScan software (Information Management Services, Inc., Silver Spring, Maryland) was used to identify geographic clusters of significantly elevated syphilis rates over space and time. The authors graphed epidemic curves for 1) core areas, 2) outbreak areas, 3) neither core nor outbreak areas, and 4) noncore areas, where noncore areas included outbreaks, and stratified these curves according to demographic characteristics. Five clusters of significantly elevated primary and secondary syphilis rates were identified. A 5-year threshold was useful for differentiating core clusters from outbreak clusters. Epidemic curves for core areas, outbreak areas, neither core nor outbreak areas, and noncore areas were perfectly synchronized in phase trends and wavelength over time, even when broken down by demographic characteristics. Between epidemics, the occurrence of syphilis affected all demographic groups equally. During an epidemic, a temporary disparity in syphilis occurrence arose and a homogeneous core group of cases could be defined.