Irene A. Doherty

Concurrent Sexual Partnerships Among Men in the United States

OBJECTIVES We sought to determine the prevalence, distribution, and correlates of US mens involvement in concurrent sexual partnerships, a sexual network pattern that speeds population dissemination of HIV. METHODS For this analysis, we compared sexual partnership dates of 4928 male respondents in the 2002 National Survey of Family Growth to determine the prevalence of concurrent sexual partnerships and evaluated associations between concurrency and demographic risk characteristics. RESULTS Approximately 11% of men had concurrent sexual partnerships during the preceding year. Concurrency was associated with being unmarried (odds ratio [OR] = 4.59; 95% confidence interval [CI] = 2.54, 8.29), non-Hispanic Black (OR=2.56; 95% CI=1.61, 4.07) or Hispanic (OR=2.25; 95% CI=1.32, 3.85) race/ethnicity, and incarceration during the past year (OR=2.10; 95% CI=1.18, 3.74). Men with concurrent sexual partnerships were also more likely to report drug or alcohol intoxication during sexual intercourse (OR=2.10; 95% CI=1.37, 3.21), nonmonogamous female sexual partners (OR=6.11; 95% CI=4.10, 9.11), and history of sexual intercourse with a man (OR = 1.93; 95% CI = 1.09, 3.42), than those without concurrent partnerships. CONCLUSIONS The higher concurrency prevalence in various groups, dense sexual networks, and mixing between high-risk subpopulations and the general population may be important factors in the US epidemic of heterosexual HIV infection.

Hiv and African Americans in the Southern United States: Sexual Networks and Social Context

Background: Heterosexual HIV transmission among African Americans in the rural southern United States has climbed in recent years. Concurrent partnerships and bridge populations have emerged as key elements in the spread of sexually transmitted infections (STIs). Goal: The goal of this study was to examine published empiric data and other literature concerning the extent of these network patterns and their relationship to the socioeconomic context among African Americans in the rural South. Study Design: The authors conducted a review of public health, medical, and social sciences literature. Results: In areas of the rural South with high STI rates, there is extensive concurrency with evidence of dense sexual networks and bridging among the general population, core group members, and other high-risk subpopulations. Qualitative research reveals socioeconomic factors that support these network patterns: low ratio of men to women, economic oppression, racial discrimination, and high incarceration rates of black men. Conclusion: Concurrency and bridging likely contribute to increased heterosexual HIV transmission among blacks in the South; contextual factors promote these network patterns in this population.

Heterosexually Transmitted Hiv Infection Among African Americans in North Carolina

Context: Rates of heterosexually transmitted HIV infection among African Americans in the southeastern United States greatly exceed those for whites. Objective: Determine risk factors for heterosexually transmitted HIV infection among African Americans. Methods: Population-based case-control study of black men and women, aged 18-61 years, reported to the North Carolina state health department with a recent diagnosis of heterosexually transmitted HIV infection and age- and gender-matched controls randomly selected from the state driver s license file. A lower-risk stratum of respondents was created to identify transmission risks among people who denied high-risk behaviors. Results: Most case subjects reported annual household income <

Sexual bridging socially and over time: A simulation model exploring the relative effects of mixing and concurrency on viral sexually transmitted infection transmission:

16,000, history of sexually transmitted diseases, and high-risk behaviors, including crack cocaine use and sex partners who injected drugs or used crack cocaine. However, 27% of case subjects (and 69% of control subjects) denied high-risk sexual partners or behavior. Risk factors for HIV infection in this subset of participants were less than high school education (adjusted odds ratio [OR] 5.0; 95% CI: 2.2, 11.1), recent concern about having enough food for themselves or their family (OR 3.7; 1.5, 8.9), and having a sexual partner who was not monogamous during the relationship with the respondent (OR 2.9; 1.3, 6.4). Conclusion: Although most heterosexually transmitted HIV infection among African Americans in the South is associated with established high-risk characteristics, poverty may be an underlying determinant of these behaviors and a contributor to infection risk even in people who do not have high-risk behaviors.

Mapping Health Data: Improved Privacy Protection With Donut Method Geomasking

Background: Sexual partnerships between people at higher and lower risk for sexually transmitted infections (STIs) (i.e., bridging) occur through dissortative mixing and concurrent partnerships, yet the relative effects of these network patterns on population STI spread are poorly understood. Goal: Using a stochastic model, the authors investigated the impact of mixing and concurrency on the spread of a persistent viral STI. Study Design: A total of 1050 populations were simulated of 1000 subjects over 400 weeks with varied concurrency levels and mixing patterns. STI prevalence and the average number of secondary transmissions per subject were analyzed with regression. Results: Mixing had a greater impact on prevalence for all groups, whereas concurrency was significant for only the lowest activity group. Mixing patterns moderated the magnitude of concurrency’s impact on secondary transmissions. Conclusions: Through connecting subgroups of differential risk, sexual mixing facilitates dissemination of STIs throughout a population. Concurrency expedites transmission by shortening the time between sexual contacts among infected and susceptible persons, particularly during the highly infectious period.

Pregnancy intentions and teenage pregnancy among Latinas: a mediation analysis.

A major challenge in mapping health data is protecting patient privacy while maintaining the spatial resolution necessary for spatial surveillance and outbreak identification. A new adaptive geomasking technique, referred to as the donut method, extends current methods of random displacement by ensuring a user-defined minimum level of geoprivacy. In donut method geomasking, each geocoded address is relocated in a random direction by at least a minimum distance, but less than a maximum distance. The authors compared the donut method with current methods of random perturbation and aggregation regarding measures of privacy protection and cluster detection performance by masking multiple disease field simulations under a range of parameters. Both the donut method and random perturbation performed better than aggregation in cluster detection measures. The performance of the donut method in geoprivacy measures was at least 42.7% higher and in cluster detection measures was less than 4.8% lower than that of random perturbation. Results show that the donut method provides a consistently higher level of privacy protection with a minimal decrease in cluster detection performance, especially in areas where the risk to individual geoprivacy is greatest.

Condom Use and Duration of Concurrent Partnerships among Men in the United States

CONTEXT The extent to which pregnancy intentions mediate the relationship between individual, familial and cultural characteristics and adolescent pregnancy is not well understood. The role of intentions may be particularly important among Latina teenagers, whose attitudes toward pregnancy are more favorable than those of other groups and whose pregnancy rates are high. METHODS Prospective, time-varying data from 2001-2004 were used to investigate whether two measures of pregnancy intentions, wantedness and happiness, mediated associations between risk factors and pregnancy among 213 Latina adolescents in San Francisco. Participants were tested for pregnancy and interviewed about pregnancy intentions, partnerships, family characteristics and activities every six months for two years. Associations and mediation were examined using logistic regression. RESULTS Neither pregnancy intention variable mediated relationships between participant characteristics and pregnancy. After adjustment for other measures, wantedness was strongly associated with pregnancy (odds ratio, 2.6), while happiness was not. Having a strong family orientation was associated with happiness (3.7) but unrelated to pregnancy. Low power in a sexual relationship with a main partner was associated with an elevated risk of pregnancy (3.3). If the pregnancy intentions of all participants were changed to definitely not wanting pregnancy, the estimated decline in pregnancy risk would be 16%. CONCLUSIONS Pregnancy intentions were important not as mediators but rather as independent risk factors for pregnancy. Differences in pregnancy rates between groups of Latinas may be less a function of intentional choice than of situational factors. Interventions and research should focus on identifying and targeting factors that hinder effective contraceptive use among teenagers who want to avoid pregnancy.

Concurrent partnerships among adolescents in a Latino community: the Mission District of San Francisco, California.

Objectives: Concurrent partnerships accelerate dissemination of STIs. Most investigations of the features of concurrent partnerships have focused on higher risk subpopulations. Goal: To assess condom use and the duration of concurrent sexual partnerships among men in the United States. Study Design: Analysis of concurrent sexual partnerships among men in the 2002 National Survey of Family Growth. We classified pairs of concurrent partnerships into 3 types: transitional, contained, and experimental concurrency, and assessed the duration of overlap. We also report the distribution of condom use at the last sexual intercourse with neither, one or both concurrent partners of each pair and characteristics of men more likely to have used condoms with neither sex partner. Results: The duration of overlap was <1 month in 32%, 1 to 3 months in 19%, and >12 months in 25% of concurrency pairs. Half (55%) of the pairs (whites, 64%; blacks, 41%) involved unprotected sex at the last sexual intercourse with at least 1 partner. The 35% of men who were more likely to use condoms with neither sex partner at the last sexual intercourse were older, white (48%), married/cohabitating (55%), and during the previous 12 months were incarcerated (49%), or used crack/cocaine (51%). Conclusions: Although blacks generally experience higher rates of STIs and HIV, in this representative sample of men in the United States, blacks in concurrent partnerships seemed to use the only available protection (condoms) against infection (apart from abstinence) more than other racial/ethnic groups. Continued investigation of features of sexual partnership patterns is critical for curbing STI and HIV transmission.

Geomasking sensitive health data and privacy protection: an evaluation using an E911 database

Objectives: Latino adolescents in the United States are disproportionately affected by sexually transmitted infections, yet knowledge of their sexual networks, particularly concurrent sex partners, is limited. Goal: The goal of this study was to describe the prevalence, patterns, and correlates of sexual concurrency among adolescents in an urban neighborhood. Study Design: The authors conducted cross-sectional analyses of 368 sexually active youth recruited from public venues within a predominantly Latino neighborhood in San Francisco, California. Results: During the prior 6 months, 20% of sexually experienced youth had concurrent partnerships, but this was more likely among males (27%) as females (12%) (odds ratio = 2.6; 95% confidence interval = 1.5–4.5). Sexually transmitted infection prevalence was too low to examine its association with concurrency. Factors that increased the likelihood of concurrency among males included: immigrant generation and being below grade level; and among females: older age and use of illegal substances. Conclusions: Ample opportunities to transmit sexually transmitted infections through concurrency were present, yet very few adolescents were infected, perhaps owing to adequate condom use within a neighborhood with low sexually transmitted infection prevalence.

Coitus Interruptus Is Not Contraception

Geomasking is used to provide privacy protection for individual address information while maintaining spatial resolution for mapping purposes. Donut geomasking and other random perturbation geomasking algorithms rely on the assumption of a homogeneously distributed population to calculate displacement distances, leading to possible under-protection of individuals when this condition is not met. Using household data from 2007, we evaluated the performance of donut geomasking in Orange County, North Carolina. We calculated the estimated k-anonymity for every household based on the assumption of uniform household distribution. We then determined the actual k-anonymity by revealing household locations contained in the county E911 database. Census block groups in mixed-use areas with high population distribution heterogeneity were the most likely to have privacy protection below selected criteria. For heterogeneous populations, we suggest tripling the minimum displacement area in the donut to protect privacy with a less than 1% error rate.