The racial disparities in STI in the U.S.: Concurrency, STI prevalence, and heterogeneity in partner selection

Examining the Association Between Affordable Care Act Medicaid Expansion and Sexually Transmitted Infection Testing Among U.S. Women

INTRODUCTION

Sexually transmitted infection (STI) rates are rising among women in the United States, increasing the importance of routine STI testing. Beginning in 2014, some states expanded Medicaid under the Affordable Care Act, providing health coverage to most individuals in and near poverty. Here, we investigate whether Medicaid expansion changed rates of STI testing among U.S. women.

METHODS

We analyzed nationally representative 2011-2017 National Survey of Family Growth data from U.S. women ages 15-44. Using difference-in-differences analysis, we assessed whether Medicaid expansion was associated with within-state changes in the prevalence of STI testing in the past 12 months, among women overall and by race/ethnicity and sexual orientation, during each year following Medicaid expansion. Models were adjusted for individual- and state-level demographic and socioeconomic factors.

RESULTS

Our sample included 14,196 U.S. women. Medicaid expansion was associated with higher STI testing rates, which increased over time. By 3 years post-expansion, expansion states had increased STI testing by 12.7 percentage points more than nonexpansion states (95% confidence interval [CI] [2.5, 23.0], p = .016). This association was imprecisely estimated within racial/ethnic and sexual orientation subgroups, but trended strongest among white, Latina, and heterosexual women, followed by Black and bisexual women (who tested more often at baseline).

CONCLUSIONS

Medicaid expansion is associated with increased STI testing among U.S. women; these benefits grew over time but varied by both race/ethnicity and sexual orientation. State governments that fail to expand Medicaid may harm their residents' health by allowing more spread of STIs.

Association of Neighborhood Economic Status and Race With Developing Pelvic Inflammatory Disease After Sexually Transmitted Infections

OBJECTIVE

To explore the association of neighborhood-level socioeconomic status (SES) and race with developing pelvic inflammatory disease (PID) after sexually transmitted infection (STI) among female adolescents and young adults in Maryland.

METHODS

We used Maryland statewide hospital claims data (outpatient and inpatient visits) for this retrospective cohort study. Female adolescents and young adults aged 15-24 years who had at least one STI from July 1, 2013, to March 31, 2015, were included. A participant entered the cohort on the date of the first STI diagnosis and was followed up until PID occurrence or 3 years after the first STI. Median household income of the participant's residential ZIP code tabulation area was used as the neighborhood-level SES. Discrete-time hazard models were used to estimate the hazard of PID.

RESULTS

Of the 2,873 participants, 88.5% were of Black race, and 67.2% were aged 20-24 years. The hazard of PID after an STI among Black women was 1.40 times that of White women (95% CI 1.06-1.85). After adjustment for age, insurance type, and number of STI events, the hazard ratio (HR) did not change. However, adding neighborhood-level SES to the model attenuated the disparity in PID after STI between Black and White women (HR 1.25, 95% CI 0.94-1.67).

CONCLUSION

Racial disparities in PID diagnosis are mitigated by neighborhood-level SES.

The Role of the Strong Black Woman in Black Female Sexual Development

Black girls and women are disproportionately impacted by sexual health disparities, including an increased risk of HIV and sexually transmitted infections (STI). Early sexual development among Black females heightens their risk of HIV/STI. Utilizing the Becoming a Sexual Black Woman (SBW) framework, this study sought to understand how early sexual development and stereotype messages may underpin HIV/STI risk, building on and furthering the discussion of the consequences of the SBW schema. To better understand this phenomenon, we conducted a secondary thematic data analysis from two previously completed grounded theory studies with Black girls and women ranging in age from 11 to 62 (N = 40). Findings revealed that Black women have been socialized to be strong and independent and yet are highly vulnerable to HIV/STI. This clash between Black girl's and women's ideals of strength and heightened vulnerability to HIV/STI presents a paradox that may help explain disparities in HIV/STI risk. Four themes emerged among both Black girls and women: complex construction of the SBW schema, burden and consequences of strength, pressure to be strong, and being strong and sexual. Findings also highlight how becoming both a strong and sexual Black woman occurs over the life course and is inherent to Black female sexual development. We discuss the implications of these findings for parents, healthcare providers, educators, and researchers with the aim to improve sexual health outcomes for Black females across the life course.

Racial disparities in uterine fibroids and endometriosis: a systematic review and application of social, structural, and political context

IMPORTANCE

Uterine fibroids and endometriosis are 2 of the leading causes of morbidity among reproductive-aged women. There are significant racial disparities in disease prevalence, incidence, age of onset, and treatment profile in fibroids. The data on endometriosis are less clear.

OBJECTIVE

To conduct a systematic review of racial disparities in prevalence of uterine fibroids and endometriosis in the United States and summarize the literature on these 2 highly prevalent benign gynecologic conditions using a framework that explicitly incorporates and acknowledges the social, structural, and political contexts as a root cause of racial disparities between Black and White women.

EVIDENCE REVIEW

A systematic review regarding racial disparities in prevalence of fibroids and endometriosis was conducted separately. Two separate searches were conducted in PubMed to identify relevant original research manuscripts and prior systematic reviews regarding racial disparities in uterine fibroids and endometriosis using standardized search terms. In addition, we conducted a structured literature search to provide social, structural, and political context of the disparities.

FINDINGS

A systematic review of the literature indicated that the prevalence of uterine fibroids was consistently higher in Black than in White women with the magnitude of the difference varying depending on population and case definition. Prevalence of endometriosis varied considerably depending on the base population and case definition, but was the same or lower among Black vs. White women. As a result of the social, structural, and political context in the United States, Black women disproportionately experience a range of exposures across the life course that may contribute to their increased uterine fibroid incidence, prevalence, and severity of uterine fibroids. However, data suggest no racial difference in the incidence of endometriosis. Nevertheless, Black women with fibroids or endometriosis experience worse clinical and surgical outcomes than their White counterparts.

CONCLUSION AND RELEVANCE

Racial disparities in uterine fibroids and endometriosis can be linked with differential exposures to suspected etiologic agents, lack of adequate access to health care, including highly skilled gynecologic surgeons, and bias and discrimination within the health care system. Eliminating these racial disparities will require solutions that address root causes of health disparities through policy, education and programs to ensure that all patients receive culturally- and structurally-competent care.

Changes in Sexual Behaviors with Opposite-Sex Partners and Sexually Transmitted Infection Outcomes Among Females and Males Ages 15-44 Years in the USA: National Survey of Family Growth, 2008-2019

Rates of reported gonorrhea and chlamydial infections have increased substantially over the past decade in the USA and disparities persist across age and race/ethnicity. We aimed to understand potential changes in sexual behaviors, sexual network attributes, and sexually transmitted infection (STI) screening that may be contributing to these trends. We analyzed data from 29,423 female and 24,605 male respondents ages 15-44 years from the National Survey of Family Growth, 2008-2019. We used survey-weighted linear or logistic regression to evaluate linear temporal trends in sexual behaviors with opposite-sex partners, network attributes, and STI testing, treatment, and diagnosis. Significant declines were observed in condom use at last vaginal sex, mean number of vaginal sex acts, proportion of condom-protected sex acts in the past 4 weeks, and racial/ethnic homophily with current partners among males and females from 2008-2010 through 2017-2019. Among males, mean number of female partners in the past 12 months and concurrency also declined, while the percent reporting ever having sex with another male increased. Past-year testing for chlamydia and any STI increased among females. Research is needed to understand how these changes interact and potentially contribute to increasing reported gonorrhea and chlamydia diagnoses and identify avenues for future intervention.

Racial disparities in access to reproductive health and fertility care in the United States

PURPOSE OF REVIEW

To examine the status of racial and ethnic inequalities in fertility care in the United States (U.S.) at inception of 2022. This review highlights addressable underpinnings for the prevalent differentials in access to and utilization of infertility treatments and underscores gaps in preventive care as key contributors to racial and ethnic disparities in risk burden for subfertility and infertility.

RECENT FINDINGS

Significant gaps in access to and utilization of fertility care are consistently reported among racial and ethnic minorities, particularly Black and Hispanic women. Access to and utilization of contraceptives, human papilloma virus vaccination rates, preexposure prophylaxis use, and differentials in treatment of common gynecologic disorders are relevant to the prevalent racial and ethnic disparities in reproductive health. The spectrum of differential in reproductive wellness and the magnitude of reproductive health burden afflicting racial minorities in the U.S. raise concerns regarding systemic and structural racism as plausible contributors to the prevalent state of affairs.

SUMMARY

Despite efforts to reform unequal reproductive health practices and policies, racial and ethnic disparities in fertility care are pervasive and persistent. In addition to measures aimed at reducing barriers to care, societal efforts must prioritize health disparity research to systematically examine underpinnings, and addressing structural racism and interpersonal biases, to correct the prevalent racial inequities and mitigate disparities.

Child Protection Intervention and the Sexual and Reproductive Health of Female Adolescents Ages 13 to 17 Years

IMPORTANCE

Child maltreatment adversely affects health and development, but evidence is needed regarding whether and how Child Protective Services (CPS) interventions may mitigate risks.

OBJECTIVE

To assess whether different forms of CPS intervention are associated with sexual and reproductive health outcomes among female adolescents investigated by CPS for suspected exposure to maltreatment during childhood.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study used linked, longitudinal, statewide administrative data from Wisconsin, including medical assistance and CPS records, to examine the rates and correlates of sexual and reproductive health outcomes (sexual transmitted infections, pregnancies, births, and high-risk sexual behavior) among 9392 female adolescents tracked from age 13 through 17 years who were investigated by CPS for suspected exposure to maltreatment prior to their 13th birthday. The study assesses how these outcomes were associated with types and frequency of CPS involvement and intervention and with adolescent and family demographic characteristics. Participants were female adolescents born from 2000 through 2002 who were investigated by Wisconsin CPS for suspected exposure to maltreatment before 13 years of age and who were covered by medical assistance at least 85% of the time from 13 to 17 years of age.

EXPOSURES

Varying levels and intensities of CPS interventions, ranging from a single investigation to adoption from foster care.

MAIN OUTCOMES AND MEASURES

Dependent variables were pregnancy, birth, sexually transmitted infection, and an aggregate measure of sexual health concerns from 13 to 17 years of age. Primary explanatory variables were the intensity of CPS intervention (investigation only, in-home services, and foster care) and frequency of maltreatment concerns (number of investigations, continued involvement during adolescence). Logistic regression was used to assess the association of CPS measures with differences in sexual health outcomes. Data were analyzed from March 1 to October 12, 2021.

RESULTS

This cohort study included 9392 female adolescents, among whom 3156 (33.6%) were born in 2000, 3064 (32.6%) in 2001, and 3173 (33.8%) in 2002; 2501 adolescents [26.6%] were Black, 1568 [16.7%] were Hispanic, 1024 [10.9%] were multiracial, 4024 [42.8%] were White, and 275 [2.9%] were listed as other [which included American Indian, Asian or Pacific Islander, or unknown race or ethnicity]). By 18 years of age, sizable proportions of maltreated female adolescents had at least 1 concerning sexual health outcome (23.5%), including diagnoses of gonorrhea, chlamydia, or trichomoniasis (8.4%), pregnancy (11.2%), and parenthood (6.1%). Compared with CPS investigation without formal intervention, foster care was associated with lower odds of pregnancy (adjusted odds ratio, 0.82; 95% C, 0.69-0.98) and live birth (adjusted odds ratio, 0.78; 95% CI, 0.61-0.99). Recurrent and ongoing CPS involvement was associated with adverse sexual health outcomes.

CONCLUSIONS AND RELEVANCE

This cohort study found that maltreated girls face increased risks of adverse sexual health outcomes in adolescence, but CPS interventions were associated with limited influence. More effective interventions are needed to help maltreated girls avoid teen pregnancy, sexually transmitted infections, and risky sexual behaviors in adolescence.

Strategies for successful designing of immunocontraceptive vaccines and recent updates in vaccine development against sexually transmitted infections - A Review

Background

Objective

Methods

Results

Conclusion

Sexual attitudes and behaviours among Arab American young adults in the USA

While the sexual behaviours of different racial and ethnic groups have been studied extensively in the USA, Arab Americans are relatively understudied. The purpose of our study is to describe sexual attitudes and behaviours of Arab American young adults, to explore gender differences and the factors associated with five primary sexual behaviours (solo and partnered masturbation, oral, vaginal and anal sex). We conducted a cross-sectional quantitative study using a self-administered survey, which included measures of Arab ethnic identity, religiosity and sexual attitudes and behaviours. The survey was completed by 100 Arab American young adults (18-25 years old). Almost half of the sample reported being engaged in at least one of the five primary sexual behaviours in the past six months. In bivariate analysis, there were significant gender differences in sexual attitudes and all the primary sexual behaviours except for anal sex. Sexual attitudes and religiosity were significant predictors of partnered masturbation, oral and vaginal sex. Our findings challenge Arab societal assumptions that unmarried Arab American young adults do not engage in sexual behaviours, including risky behaviours, warranting further research to prevent unintended sexual health outcomes.

What Will It Take to End HIV in the United States? : A Comprehensive, Local-Level Modeling Study

BACKGROUND

The Ending the HIV Epidemic (EHE) initiative aims to reduce incident HIV infections by 90% over a span of 10 years. The intensity of interventions needed to achieve this for local epidemics is unclear.

OBJECTIVE

To estimate the effect of HIV interventions at the city level.

DESIGN

A compartmental model of city-level HIV transmission stratified by age, race, sex, and HIV risk factor was developed and calibrated.

SETTING

32 priority metropolitan statistical areas (MSAs).

PATIENTS

Simulated populations in each MSA.

INTERVENTION

Combinations of HIV testing and preexposure prophylaxis (PrEP) coverage among those at risk for HIV, plus viral suppression in persons with diagnosed HIV infection.

MEASUREMENTS

The primary outcome was the projected reduction in incident cases from 2020 to 2030.

RESULTS

Absent intervention, HIV incidence was projected to decrease by 19% across all 32 MSAs. Modest increases in testing (1.25-fold per year), PrEP coverage (5 percentage points), and viral suppression (10 percentage points) across the population could achieve reductions of 34% to 67% by 2030. Twenty-five percent PrEP coverage, testing twice a year on average, and 90% viral suppression among young Black and Hispanic men who have sex with men (MSM) achieved similar reductions (13% to 68%). Including all MSM and persons who inject drugs could reduce incidence by 48% to 90%. Thirteen of 32 MSAs could achieve greater than 90% reductions in HIV incidence with large-scale interventions that include heterosexuals. A web application with location-specific results is publicly available (www.jheem.org).

LIMITATION

The COVID-19 pandemic was not represented.

CONCLUSION

Large reductions in HIV incidence are achievable with substantial investment, but the EHE goals will be difficult to achieve in most locations. An interactive model that can help policymakers maximize the effect in their local environments is presented.

PRIMARY FUNDING SOURCE

National Institutes of Health.

Risk assessment for HIV infection in men who have sex with men and the contribution of sexual partner networks

This study aimed to evaluate the risk of HIV infection in men who have sex with men (MSM) by developing an index that considers sex partner networks. The index variables were age, ethnicity/skin color, schooling, relationship type, condom use in receptive and insertive relationships, self-perception of the possibility of HIV infection, sexually transmitted infections, and rapid HIV testing results. We used data from a cross-sectional MSM egocentric network survey conducted in Rio de Janeiro between 2014 and 2015. The initial research volunteer is called ego, each partner is called alter, and each pair of people in a relationship is called the dyad. Multiple logistic regression was used to define the coefficients of the equations for the elaboration of the indices. The index ranged from 0 to 1; the closer to 1, the higher the risk of HIV infection. HIV prevalence was 13.9% among egos. The mean egos index with an HIV-reactive test was 57% higher than non-reactive, and the same profile was observed in the index values of dyads. The index allowed the incorporation of network data through the dyads and contributed to the identification of individuals with a higher likelihood of acquiring HIV.

Prevalence of Chlamydia trachomatis Infection in Young Women and Associated Predictors

BACKGROUND

Chlamydia trachomatis (CT) infection remains highly prevalent, and young women are disproportionately affected. Most CT-infected women are asymptomatic, and their infection often goes unrecognized and untreated. We hypothesized that testing for active CT infection with molecular diagnostics and obtaining a reported history of CT infection underestimate the prevalence of current and past CT infection, and incorporating serum CT antibody testing in addition to these other prevalence measures would generate more accurate estimates of the prevalence of CT infection in asymptomatic young women.

METHODS

We enrolled 362 asymptomatic women aged 16 to 29 years at 4 different clinical settings in Birmingham, AL, between August 2016 and January 2020 and determined the prevalence of CT infection based on having 1 or more of the following prevalence measures: an active urogenital CT infection based on molecular testing, reported prior CT infection, and/or being CT seropositive. Multivariable regression analysis was used to determine predictors of the prevalence of CT infection after adjustment for participant characteristics.

RESULTS

The prevalence of CT infection was 67.7% (95% confidence interval, 62.6%-72.5%). Addition of CT antibody testing to the other individual prevalence measures more than doubled the CT infection prevalence. Non-Hispanic Black race, reported prior gonorrhea, and reported prior trichomoniasis predicted a higher prevalence of CT infection.

CONCLUSIONS

More than half of women were unaware of ever having CT infection, suggesting many were at risk for CT-associated reproductive complications. These data reinforce the need to adhere to chlamydia screening guidelines and to increase screening coverage in those at risk.

Racial/Ethnic Disparities in Female Sexual Health from Adolescence to Young Adulthood: How Adolescent Characteristics Matter?

STUDY OBJECTIVE

To describe sexual initiation patterns in female adolescents and examine their association with adolescent characteristics and racial disparities in adverse sexual health across adolescence into early adulthood.

DESIGN

A prospective, longitudinal, observational study from adolescence to adulthood.

SETTING

Nationally representative, the National Longitudinal Study of Adolescent to Adult Health data, in the range of 24-32 years old at final assessment.

PARTICIPANTS

Data from 43,577 US women from 1994 to 2008.

INTERVENTIONS AND MAIN OUTCOME MEASURES

Adolescent sex-related characteristics at the individual-, family-, and school peer-level were assessed, and multiple sex partners, sexually transmitted infections (STIs)/HIV, and intimate partner violence (IPV) were longitudinally tracked. The sexual initiation pattern and its longitudinal association with sexual health were analyzed using latent class analysis and mixed effects Poisson regression models.

RESULTS

Of the 43,577 subjects, the sexual initiation patterns were determined as normative (n = 28,712, 65.9%), late (n = 10,799, 24.8%), and early but unempowered (n = 4,066, 9.3%). The highest rate of the early-unempowered group was shown in Hispanic individuals (1,054/7,307 = 14.4%); they were more likely to be depressed, unsatisfied with their bodies, receiving welfare, and have less educated/permissive parents to their sexual initiation than others. The late group had a higher body mass index and greater satisfaction with their bodies. The highest number of STIs/HIV and IPV victimization was shown in non-Hispanic Black (NHB) and Hispanic individuals, respectively. However, NHB females' higher number of STIs/HIV was shown in the late/normative groups, not in the early-unempowered group. Among Hispanic females, adolescent sexual initiation patterns were not directly associated with their frequent IPV victimization.

CONCLUSION

NHB females' higher STI/HIV in late/normative groups and Hispanic females' frequent IPV victimization regardless of their sexual initiation patterns might indicate that racial/ethnic disparities in female sexual health was not directly determined by adolescent risk behaviors.

Incidence of Nongonococcal Urethritis in Men Who Have Sex With Women and Associated Risk Factors

BACKGROUND

Incidence and risk factors for nongonococcal urethritis (NGU) remain poorly defined. We conducted a cohort study to estimate the incidence of NGU and identify risk factors in men who have sex with women.

METHODS

We enrolled cisgender male sexually transmitted disease clinic attendees 16 years or older who reported exclusively female partners. At enrollment and 6 monthly follow-up visits, men underwent a clinical examination, provided urethral swab and urine specimens, completed a sexual behavior survey and biweekly diaries, and were tested for Chlamydia trachomatis (CT) and Mycoplasma genitalium (MG) using Aptima assays (Hologic, Inc). Nongonococcal urethritis was defined as ≥5 polymorphonuclear leukocytes per high-power field plus either urethral symptoms or visible discharge. We estimated the incidence of NGU overall, asymptomatic and symptomatic NGU, non-CT/non-MG NGU, and CT/MG-associated NGU using Poisson regression for clustered outcomes. We performed relative risk binomial regression for clustered data to identify characteristics associated with incident NGU.

RESULTS

From August 2014 to July 2018, 307 participants at risk for NGU contributed 109.4 person-years. Median age was 32 years, and 52% were White. At enrollment, 107 men had NGU; of these, 88% were symptomatic, 27% had CT, and 22% had MG. Fifty men had 60 cases of incident NGU (incidence rate, 56 per 100 person-years; 95% confidence interval, 43-74). Unlike prevalent NGU at enrollment, CT/MG-associated incident NGU was rare (incidence rate, 7; 95% confidence interval [CI], 4-15), and most (78%) incident NGU was asymptomatic. Risk factors for incident NGU were ≤ high school education (adjusted rate ratio [ARR], 2.45; 95% CI, 1.19-5.00), history of CT (ARR, 2.15; 95% CI, 1.08-4.27), history of NGU (ARR, 2.67; 95% CI, 1.27-5.62), and NGU at enrollment (ARR, 2.03; 95% CI, 1.04-3.98). Neither condom use nor having a new partner was associated with incident NGU; Black race was only associated with incident symptomatic and non-CT/non-MG NGU.

CONCLUSIONS

Incidence of NGU was high, predominantly non-CT/non-MG and asymptomatic. Future studies should investigate the etiology and clinical significance of asymptomatic NGU.

Partnership dynamics in mathematical models and implications for representation of sexually transmitted infections: a review

Mathematical models of sexually transmitted disease (STI) are increasingly relied on to inform policy, practice, and resource allocation. Because STI transmission requires sexual contact between two or more people, a model's ability to represent the dynamics of sexual partnerships can influence the validity of findings. This ability is to a large extent constrained by the model type, as different modeling frameworks vary in their capability to capture patterns of sexual contact at individual, partnership, and network levels. In this paper, we classify models into three groups: compartmental, individual-based, and statistical network models. For each framework, we describe the basic model structure and discuss key aspects of sexual partnership dynamics: how and with whom partnerships are formed, partnership duration and dissolution, and temporal overlap in partnerships (concurrency). We illustrate the potential implications of accurately accounting for partnership dynamics, but these effects depend on characteristics of both the population and pathogen; the combined impact of these partnership and epidemiologic dynamics can be difficult to predict. While each of the reviewed model frameworks may be appropriate to inform certain research or policy questions, modelers and consumers of models should carefully consider the implications of sexual partnership dynamics for the questions under study.

Dyadic Intervention for Sexually Transmitted Infection Prevention in Urban Adolescents and Young Adults (The SEXPERIENCE Study): Protocol for a Randomized Controlled Trial (Preprint)

Background

Adolescents and young adults (AYA) aged younger than 25 years have the highest rates of sexually transmitted infections (STIs) in the United States. Current STI prevention strategies for AYA rely primarily on individual approaches, leaving sexual partners with significant unmet sexual and reproductive health care and health education needs. Dyadic interventions may hold promise for harnessing the power of communal coping within relationship dynamics to enhance sexual decision making, communication, and behavior changes that reduce the future risk of STIs.

Objective

This paper describes the protocol and research methods of a dyad-based behavioral intervention that augments individual evidence-based interventions with joint health education counseling for heterosexual AYA dyads within a primary care setting. The trial aims to improve partner communication and collaborative sexual decision making and promote the adoption of sexual behaviors such as consistent condom use. The primary objective of this study is to assess the feasibility, acceptability, and effectiveness of a dyadic intervention targeted at preventing STIs in heterosexual couples in an urban setting.

Methods

A total of 100 AYA (50 dyads) aged 16 to 25 years, engaged in heterosexual intercourse, who reside in the city and are willing to recruit their main sexual partner for the study will be recruited and randomized into 2 groups, an intervention arm and a control arm. Participants will be recruited from an AYA medicine clinic and by using social media (Facebook and Instagram). The index participant and partner will complete a single individual session separately (Sister to Sister or Focus on the Future) with a gender-matched health educator. Dyads will then be randomized to receive an additional joint debriefing session together to discuss relationship dynamics, condom negotiation, etc. Participants will separately complete a telephone interview 6 weeks postintervention to determine the feasibility, acceptability, and impact of the intervention on mutual sexual negotiation, consistency of condom use, and communal coping skills, etc.

Results

So far, 25.4% (44/173) of eligible participants have been enrolled and randomized. Participants are mostly female (20/22, 91%), with at least a high school diploma (19/22, 86%), and 9 average lifetime sexual partners. Acceptability is high, with 98% (43/44) of participants expressing satisfaction with their study experience; 100% of dyads recruited were still together at 6-week follow-up.

Conclusions

Findings from this study will add to the current literature on the approaches to STI prevention, and its success will inform its application in risk reduction counseling for youth who are most at risk.

Trial Registration

Clinical Trials.gov NCT03275168; https://www.clinicaltrials.gov/ct2/history/NCT03275168

International Registered Report Identifier (IRRID)

DERR1-10.2196/29389

Sexual Network Patterns and Their Association With Genital and Anal Human Papillomavirus Infection in Adolescent and Young Men

PURPOSE

This study aimed to determine individual- and partner-level factors associated with human papillomavirus (HPV) infection in vaccinated and unvaccinated men.

METHODS

A total of 747 men, aged 13-26 years, completed a survey of sexual behaviors and were tested for genital and perianal/anal HPV (36 types). Sexual network variables included recent and lifetime concurrency (being in more than one sexual relationship at the same time) and recent sex partner discordance (by race, ethnicity, age, and number of sexual partners). We determined individual-level and sexual network variables associated with ≥1 HPV type and HPV16/18, stratified by vaccination status, using separate multivariable logistic regression models.

RESULTS

Participants' mean age was 21.2 years; 64% were positive for ≥1 HPV type and 21% for HPV16/18. Factors associated with ≥1 HPV type in unvaccinated men included recruitment site and lifetime concurrency. Factors associated with ≥1 HPV type among vaccinated men included recruitment site, Chlamydia history, main male partner, number of lifetime female partners, and no condom use with female partner. Factors associated with HPV16/18 in unvaccinated men included race and partner concurrency. Factors associated with HPV16/18 in vaccinated men included ethnicity, main male partner, and recent concurrency.

CONCLUSIONS

Sexual network variables associated with HPV infection were different based on vaccination status and HPV type, suggesting risk factors for HPV infection may change as the proportion of vaccinated men increases. In addition, participant report of concurrency and not knowing whether one had practiced concurrency were consistent risk factors; clinicians should consider including concurrency in the sexual history to determine the risk of HPV.

Integrating Individual and Contextual Factors to Explain Disparities in HIV/STI Among Heterosexual African American Youth: A Contemporary Literature Review and Social Ecological Model

Heterosexual African American youth face substantial disparities in sexual health consequences such as HIV and STI. Based on the social ecological framework, the current paper provides a comprehensive, narrative review of the past 14 years of literature examining HIV/STI risk, including risky sexual behavior, among heterosexual African American youth and a conceptual model of risk among this population. The review found that individual psychological and biological factors are insufficient to explain the sexual health disparities faced by this group; instead, structural disadvantage, interpersonal risk, and community dysfunction contribute to the disparity in HIV/STI outcomes directly and indirectly through individual psychological factors. The conceptual model presented suggests that for African American youth, (1) HIV/STI risk commonly begins at the structural level and trickles down to the community, social, and individual levels, (2) risk works in a positive feedback system such that downstream effects compound the influence of structural risks, and (3) contextual and individual risk factors must be considered within the advanced stage of the epidemic facing this population. Despite advanced HIV and STI epidemics among heterosexual African American youth, multisystemic interventions that target structural risk factors and their downstream effects are posited to reduce the disparity among this high-risk population.

Sexually Transmitted Infections Prevalence in the United States and the Relationship to Social Determinants of Health

Rates of sexually transmitted infections (STI) are on the rise in the United States. Some STIs are at an all-time high. Research has shown that there is a higher prevalence of STIs among some racial and ethnic groups as compared with whites. Factors contributing to this endemic have been explored. Although some individual-level risk factors have previously been identified, data overwhelmingly suggest that social determinants of health are key factors in the overall increase in STIs. Additionally, these social factors have contributed to disparities in STI acquisition. Population-specific interventions targeting social factors are necessary in reducing the rates of STIs.

Prevalence of Trichomonas vaginalis Infection Among US Males, 2013-2016

Background

Trichomoniasis results from adhesion of Trichomonas vaginalis to the mucous membrane of the urethra or vagina. It has been estimated to have a higher incidence rate than both gonorrhea and chlamydia combined. Although females can experience both clinical symptoms and obstetrical complications, male infections are largely asymptomatic and often unreported. We aim to estimate the prevalence of trichomoniasis in US males using the National Health and Nutrition Examination Survey (NHANES) database.

Methods

The NHANES database was queried for all men aged 18-59 years during the years 2013-2016. During these years, the survey included urine testing for trichomoniasis using transcription-mediated amplification. Information was also obtained regarding patient demographics and other sexually transmitted infections.

Results

Overall, 0.49% of men aged 18-59 years tested positive for trichomoniasis. The highest rate was seen in black men (3.6%). There was no significant association with trichomoniasis and age. Higher rates of infection were seen in smokers, those with herpes simplex virus type 2 (HSV-2) infection, men who had sex at an early age, those with less condom usage, and those with more lifetime sexual partners.

Conclusion

The rates of trichomonas infection in US males are lower than in women. Infections are strongly associated with black males, HSV-2 infection, and other factors known to increase rates of sexually transmitted infection. This information may be helpful for counseling, screening, and management of patients.

Factors influencing sexual and reproductive health of Muslim women: a systematic review

BACKGROUND

In Islamic societies, issues related to sexual and reproductive health (SRH) are rarely discussed and considered sensitive subjects. This review aimed to identify any personal, religious, cultural, or structural barriers to SRH service and education among Muslim women worldwide.

METHODS

A search for qualitative and quantitative studies was conducted on seven electronic databases. A narrative synthesis using thematic analysis was conducted.

RESULTS

Fifty-nine studies were included from 22 countries: 19 qualitative, 38 quantitative and two mixed methods. Many Muslim women have poor SRH knowledge, and negative attitudes which influence their access to, and use of SRH services. Barriers to contraception use among Muslim women included a lack of basic reproductive knowledge, insufficient knowledge about contraception, misconceptions, and negative attitudes. Women had negative attitudes towards family planning for limiting the number of children but not for child spacing, which reflected religious views towards family planning. Religious and cultural beliefs were barriers to contraception use and access to SRH services and information. Family and the community have a significant impact on women's contraceptive use and access to SRH services. Husband and family opposition played a significant role in contraception access and use. Fear of stigmatization and being labelled as having pre-marital sexual relations among unmarried women acted as the main barrier to accessing contraception and seeking SRH information and services.

CONCLUSION

The findings reveal that there are multiple levels of factors that influence Muslim women's SRH. Poor SRH knowledge and practices among Muslim women is complex matter that is affected by personal, community, cultural, religious factors and existing policies and regulations. All these factors overlap and are affected by each other. There is an urgent need for interventions addressing modifiable barriers to SRH education and services to improve knowledge, informed choice and access to services to facilitate better sexual and reproductive wellbeing for Muslim women. It is important to note that while this review aimed to report findings on Muslim women, we acknowledge that significant variations exist within every culture and religion.

Moving the prevention timeline: A scoping review of the literature on precursors to sexual risk in early adolescence among youth of color

INTRODUCTION

Sexual health disparities are leading causes of morbidity among youth of color in the United States. We conducted a scoping review of the literature on precursors to sexual risk-taking among young adolescents of color (ages 10-14) to assess precedents of sexual experience and their utility as measurable proximal constructs and behaviors gauging sexual risk and sexual risk prevention efforts.

METHODS

This study was conducted using the PRISMA extension for scoping reviews (PRISMA-ScR) guidelines. We searched for quantitative studies that assessed the relationships between precursors and subsequent sexual behaviors, incorporated youth of color, and specified young adolescents as the study sample. All articles were in English, however we explored both U.S. and International databases.

RESULTS

The database search yielded 11 studies published between 2000 and 2017. Most literature focused on youth in urban settings, and on Black and Latinx youth, while only two addressed the special circumstances of American Indian and Alaska Native youth. Sex expectancies outcomes for youth of color were likely to predict sexual risk taking and self-efficacy about sex was related to abstinence.

CONCLUSIONS

Etiologic studies that seek to understand precursors to sexual risk taking among youth of color are limited and this paucity truncates the ability to develop sexual risk prevention programs for the age group in which prevention is most needed.

High Rates of Repeat Chlamydial Infections Among Young Women-Louisiana, 2000-2015

BACKGROUND

Chlamydial infections are common among young women and can lead to serious reproductive health complications. We assessed the risk of reported repeat chlamydial infection among young women in Louisiana and time interval between infections by age and race/ethnicity.

METHODS

We analyzed surveillance data on chlamydial infections reported among women in Louisiana from January 1, 2000, to December 31, 2015. Multiple reports for the same person were matched using unique codes. Chlamydial infections reported more than 30 days after a previous positive test were considered new infections. Women aged 15 to 34 years at first infection during 2000 to 2012 were censored after 3 years or after they had a repeat infection. Cumulative incidence and incidence rate of repeat chlamydial infection among women were determined by year of first infection. Race- and age-specific results were obtained using stratified analyses.

RESULTS

One in 4 women diagnosed with a chlamydial infection at 15-34 years of age in Louisiana had a reported repeat infection in 3 years or less. Risk of repeat infection increased for younger women, racial/ethnic minorities, and women in more recent cohorts. Young black women aged 15 to 19 years in 2012 had the highest risk (44%). Black women also had shorter intervals between infections than white women.

CONCLUSIONS

Repeat chlamydial infections were common, especially among young black women. The true number is likely higher because surveillance data only count infections that were detected and reported. Comprehensive prevention strategies are needed to address high rates of repeat chlamydial infections among women.

Reviewing the Composition of Vaginal Microbiota: Inclusion of Nutrition and Probiotic Factors in the Maintenance of Eubiosis

The vaginal microbiota has importance in preserving vaginal health and defending the host against disease. The advent of new molecular techniques and computer science has allowed researchers to discover microbial composition in depth and associate the structure of vaginal microbial communities. There is a consensus that vaginal flora is grouped into a restricted number of communities, although the structure of the community is constantly changing. Certain Community-State Types (CSTs) are more associated with poor reproductive outcomes and sexually transmitted diseases (STDs) meanwhile, CSTs dominated by Lactobacillus species—particularly Lactobacillus crispatus—are more related to vaginal health. In this work, we have reviewed how modifiable and non-modifiable factors may affect normal vaginal microbiota homeostasis—including sexual behavior, race or ethnicity, and hygiene. Special interest has been given to how the use of probiotics, diet intake, and use of hormone replacement therapies (HRTs) can potentially impact vaginal microbiota composition.

School suspension predicts trichomoniasis five years later in a matched sample

BACKGROUND

Young adults who were suspended from school during adolescence are more likely than matched non-suspended youth to be arrested, on probation, or not graduate from high school, which are STI risk factors. This study evaluates whether suspension is a marker for STI risk among young adults who avoid subsequent negative effects.

METHODS

This study evaluated whether suspension predicts a positive test for chlamydia, gonorrhea, or trichomoniasis in a urine sample using matched sampling in the National Longitudinal Study of Adolescent and Adult Health (Add Health), and evaluated potential mediators between suspension and STI status using causal mediation analysis. We used Mahalanobis and exact matched sampling within propensity score calipers to compare 381 youth suspended for the first time in a 1-year period with 980 non-suspended youth. The suspended and non-suspended youth were similar on 67 pre-suspension variables. We evaluated STI outcomes 5 years after suspension.

RESULTS

Before matching, suspended youth were more likely to test positive for trichomoniasis and gonorrhea, but not chlamydia, than non-suspended youth. Suspended youth were more likely to test positive for trichomoniasis 5 years after suspension than matched non-suspended youth (OR = 2.87 (1.40, 5.99)). Below-median household income before suspension explained 9% of the suspension-trichomoniasis association (p = 0.02), but criminal justice involvement and educational attainment were not statistically significantly mediators.

CONCLUSIONS

School suspension is a marker for STI risk. Punishing adolescents for initial deviance may cause them to associate with riskier sexual networks even if they graduate high school and avoid criminal justice system involvement. Suspension may compound disadvantages for youth from below-median-income families, who have fewer resources for recovering from setbacks.

Estimated Impact of Screening on Gonorrhea Epidemiology in the United States: Insights From a Mathematical Model

The burden of gonorrhea infections in the United States is high. There are marked disparities by race/ethnicity and sexual orientation. We quantified the impact of screening and treatment on gonorrhea rates in the US population aged 15 to 39 years for the period 2000 to 2015 and estimated the impact that alternative screening strategies might have had over the same period.

METHODS

We developed a national-level transmission model that divides the population by race/ethnicity, preferred gender of sex partners, age, gender, and sexual activity level. We compared our fitted model ("base case") to 4 alternative strategies: (i) no screening, (ii) full adherence to current screening guidelines, (iii) annual universal screening, or (iv) enhanced screening in groups with the highest infection burden. Main outcomes were incidence, infections averted, and incidence rate ratios by race/ethnicity. Mean values and 95% credible intervals were calculated from 1000 draws from parameter posterior distributions.

RESULTS

The calibrated model reproduced observed trends in gonorrhea, including disparities in infection burden by race/ethnicity. We estimated that screening for gonorrhea from 2000 to 2015 averted 30% (95% credible intervals, 18-44%) of total infections that would otherwise have occurred. All alternative active screening strategies were estimated to further reduce, but not eliminate, gonorrhea infections relative to the base case, with differential impacts on the subpopulations of interest.

CONCLUSIONS

Our model results suggest that screening has reduced gonorrhea incidence in the US population. Additional reductions in infection burden may have been possible over this period with increased screening, but elimination was unlikely.

Participation shifts explain degree distributions in a human communications network

Human interpersonal communications drive political, technological, and economic systems, placing importance on network link prediction as a fundamental problem of the sciences. These systems are often described at the network-level by degree counts —the number of communication links associated with individuals in the network—that often follow approximate Pareto distributions, a divergence from Poisson-distributed counts associated with random chance. A defining challenge is to understand the inter-personal dynamics that give rise to such heavy-tailed degree distributions at the network-level; primarily, these distributions are explained by preferential attachment, which, under certain conditions, can create power law distributions; preferential attachment’s prediction of these distributions breaks down, however, in conditions with no network growth. Analysis of an organization’s email network suggests that these degree distributions may be caused by the existence of individual participation-shift dynamics that are necessary for coherent communication between humans. We find that the email network’s degree distribution is best explained by turn-taking and turn-continuing norms present in most social network communication. We thus describe a mechanism to explain a long-tailed degree distribution in conditions with no network growth.

Adolescent-Parent Dyadic Retention in an Interview Study and Changes in Willingness to Participate in a Hypothetical Microbicide Safety Study

STUDY OBJECTIVE

In this study we describe adolescent and parent retention and changes in willingness to participate (WTP) in research among adolescents, parents, and adolescent-parent dyads.

DESIGN AND SETTING

Adolescent-parent dyads were recruited to participate in a longitudinal study to assess research participation attitudes using simultaneous individual interviews of the adolescent and parent with a return visit 1 year later using the same interview.

PARTICIPANTS

Adolescents (14-17 years old) and their parents.

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

The relationship between participant characteristics and dyad retention was assessed. WTP was measured on a Likert scale and dichotomized (willing/unwilling) to assess changes in WTP attitudes over time for adolescents, parents, and dyads.

RESULTS

Eighty-three percent of the 300 dyads were retained. Dyads in which there was successful contact with the parent before follow-up were more likely to be retained (odds ratio, 4.88; 95% confidence interval, 2.57-9.26). For adolescents at baseline, 59% were willing to participate and 55% were willing to participate at follow-up (McNemar S = 0.91; P = .34). For parents at baseline, 51% were willing to participate and 57% were willing to participate at follow-up (McNemar S = 5.12; P = .02). For dyads at baseline, 57% were concordant (in either direction) and 70% of dyads were concordant at follow-up (McNemar S = 10.56; P = .001).

CONCLUSION

Over 1 year, parent contact might positively influence successful adolescent retention. Parents become more willing to let their adolescents participate over time, with dyads becoming more concordant about research participation.

Human papillomavirus vaccination and the role of herd effects in future cancer control planning: a review

INTRODUCTION

Vaccine herd effects are the indirect protection that vaccinated persons provide to those who remain susceptible to infection, due to the reduced transmission of infections. Herd effects have been an important part of the discourse on how to best implement human papillomavirus (HPV) vaccines and prevent HPV-related diseases.

AREAS COVERED

In this paper, we review the theory of HPV vaccine herd effects derived from mathematical models, give an account of observed HPV vaccine herd effects worldwide, and examine the implications of vaccine herd effects for future cervical cancer screening efforts.

EXPERT COMMENTARY

HPV vaccine herd effects improve the cost-effectiveness of vaccinating preadolescent girls, but contribute to making gender-neutral vaccination less economically efficient. Vaccination coverage and sexual mixing patterns by age are strong determinants of herd effects. Many countries worldwide are starting to observe reductions in HPV-related outcomes likely attributable to herd effects, most notably declining anogenital warts in young men, and declining HPV-16/18 infection prevalence in young unvaccinated women. Policy makers making recommendations for cervical cancer screening will have to consider HPV vaccination coverage and herd effects, as these will affect the positive predictive value of screening and the risk of cervical cancer in unvaccinated women.

Assortativity and Mixing by Sexual Behaviors and Sociodemographic Characteristics in Young Adult Heterosexual Dating Partnerships

BACKGROUND

Assortative sexual mixing, the tendency for individuals to choose partners with similar characteristics to themselves, may be an important contributor to the unequal distribution of sexually transmitted infections in populations. We analyzed the tendency for assortative mixing on demographic and sexual behaviors characteristics in newly formed young adults dating partnerships.

METHODS

Women aged 18 to 24 years and their male sexual partners of no more than 6 months were recruited during 2005 to 2010 at universities in Montreal, Canada. New dating partners were also prospectively recruited during the 2-year follow-up. We used Spearman and Newman coefficients to examine correlations between partners' demographic characteristics and sexual behaviors, and multivariable logistic modeling to determine which characteristics were assortative.

RESULTS

Participants in 502 recruited partnerships were assortative on age (Spearman P = 0.60), smoking behavior (P = 0.43), ethnicity (Newman coefficient=0.39), lifetime number of sexual partners (P = 0.36), sex partner acquisition rates (P = 0.22), gap length between partnerships (P = 0.20), and on whether they had concurrent partners (P = 0.33). Partners were assortative on number of lifetime partners, sexual partner acquisition rates, concurrency, and gap length between partnerships even after adjustment for demographic characteristics. Reported condom use was correlated between initial and subsequently recruited partners (P = 0.35). There was little correlation between the frequencies of vaginal/oral/digital/anal sex between subsequent partnerships.

CONCLUSIONS

Dating partnerships were substantially assortative on various sexual behaviors as well as demographic characteristics. Though not a representative population sample, our recruitment of relatively new partnerships reduces survivor bias inherent to cross-sectional surveys where stable long-term partnerships are more likely to be sampled.

HIV-Related Communication and Safe Sex Practices among Heterosexual Black Men: A Qualitative Report

HIV prevention efforts have given limited attention to the influence of social norms on the process of communicating about safer sex practices among heterosexual Black men. To address this and inform the development of an HIV prevention behavioral intervention for heterosexual African American men, we conducted computerized, structured interviews with 61 men living in high HIV prevalence neighborhoods in New York City to participate in either one of the five focus group interviews and/or an in-depth qualitative interview. Participants had a mean age of 33 years, 25% held less than a high school education, 66% earned an annual income of $10,000 or less, and 86% had a history of incarceration Qualitative analysis was used to identify emergent themes within the domains of condom use communication, HIV status disclosure with sexual partners, and general HIV knowledge among peers. Thematic analyses revealed that communication was hindered by (1) low perception of risk of sex partners (2) relationship insecurities and (3) HIV stigma within the community and between sex partners. Most communication related to condom use was based on their perception of their sex partner's HIV risk and fear of contracting HIV and/or a partner's reaction to proposing or using condoms. Discussions related to HIV status elicited concerns of being labeled as HIV-positive or leading to unprotected sex. Communication among peers was rare due in part to the stigma of HIV in the Black community. Effective HIV interventions for heterosexual should include communication strategies that address the cultural norms that influence safe sex practices.

Vaginal Microbiome and Its Relationship to Behavior, Sexual Health, and Sexually Transmitted Diseases

The vaginal microbiota has great significance in maintaining vaginal health and protecting the host from disease. Recent advances in molecular techniques and informatics allow researchers to explore microbial composition in detail and to compare the structure of vaginal microbial communities with behavior and health outcomes, particularly acquisition and transmission of sexually transmitted diseases (STDs) and poor birth outcomes. Vaginal flora have been found to cluster into a limited number of communities, although community structure is dynamic. Certain community types are more associated with poor reproductive outcomes and STDs; communities dominated by Lactobacillus species, particularly Lactobacillus crispatus, are most associated with vaginal health. Modifiable and nonmodifiable factors are strongly associated with community composition, including behavior, race or ethnicity, and hygiene. In this review, we describe the state of the science on the vaginal microbiome and its relationship to behavior, sexual health, and STDs, including determinants of the microbiome that go beyond an individual level.

Bypassing the 'rapid-clearance-in-males-buffer': A fourth mechanism to explain how concurrency enhances STI spread

A number of sexually transmitted infections (STIs) persist for a considerably shorter period in the male urethra than the vagina. If the gap between sequential partnerships is longer than the duration of STI colonization in males, then this would protect future female partners from this STI in a setting of serial monogamy. If, however, males have more than one partner at a time (concurrency), then this would enable the STI to bypass this gap/buffer. We therefore propose bypassing the rapid-clearance-in-males-buffer as a fourth mechanism, whereby concurrency could enhance the spread of STIs.

Black-White Differences in Sex and Contraceptive Use Among Young Women

This study examines black-white and other sociodemographic differences in young women's sexual and contraceptive behaviors, using new longitudinal data from a weekly journal-based study of 1,003 18- to 19-year-old women spanning 2.5 years. We investigate hypotheses about dynamic processes in these behaviors during early adulthood in order to shed light on persisting racial differences in rates of unintended pregnancies in the United States. We find that net of other sociodemographic characteristics and adolescent experiences with sex and pregnancy, black women spent less time in relationships and had sex less frequently in their relationships than white women, but did not differ in the number of relationships they formed or in their frequency or consistency of contraceptive use within relationships. Black women were more likely to use less effective methods for pregnancy prevention (e.g., condoms) than white women, who tended to use more effective methods (e.g., oral contraceptives). And although the most effective method for pregnancy prevention-long-acting reversible contraception (LARC)-was used more often by black women than white women, LARC use was low in both groups. In addition, black women did not differ from white women in their number of discontinuations or different methods used and had fewer contraceptive method switches. Further, we find that net of race and adolescent experiences with sex and pregnancy, women from more-disadvantaged backgrounds had fewer and longer (and thus potentially more serious) relationships, used contraception less frequently (but not less consistently), and used less effective methods (condoms) than women from more-advantaged backgrounds.

Beyond Risk Compensation: Clusters of Antiretroviral Treatment (ART) Users in Sexual Networks Can Modify the Impact of ART on HIV Incidence

Introduction

Concerns about risk compensation—increased risk behaviours in response to a perception of reduced HIV transmission risk—after the initiation of ART have largely been dispelled in empirical studies, but other changes in sexual networking patterns may still modify the effects of ART on HIV incidence.

Methods

We developed an exploratory mathematical model of HIV transmission that incorporates the possibility of ART clusters, i.e. subsets of the sexual network in which the density of ART patients is much higher than in the rest of the network. Such clusters may emerge as a result of ART homophily—a tendency for ART patients to preferentially form and maintain relationships with other ART patients. We assessed whether ART clusters may affect the impact of ART on HIV incidence, and how the influence of this effect-modifying variable depends on contextual variables such as HIV prevalence, HIV serosorting, coverage of HIV testing and ART, and adherence to ART.

Results

ART homophily can modify the impact of ART on HIV incidence in both directions. In concentrated epidemics and generalized epidemics with moderate HIV prevalence (≈ 10%), ART clusters can enhance the impact of ART on HIV incidence, especially when adherence to ART is poor. In hyperendemic settings (≈ 35% HIV prevalence), ART clusters can reduce the impact of ART on HIV incidence when adherence to ART is high but few people living with HIV (PLWH) have been diagnosed. In all contexts, the effects of ART clusters on HIV epidemic dynamics are distinct from those of HIV serosorting.

Conclusions

Depending on the programmatic and epidemiological context, ART clusters may enhance or reduce the impact of ART on HIV incidence, in contrast to serosorting, which always leads to a lower impact of ART on HIV incidence. ART homophily and the emergence of ART clusters should be measured empirically and incorporated into more refined models used to plan and evaluate ART programmes.

The Global Epidemiology of Syphilis in the Past Century - A Systematic Review Based on Antenatal Syphilis Prevalence

BACKGROUND

How can we explain the uneven decline of syphilis around the world following the introduction of penicillin? In this paper we use antenatal syphilis prevalence (ASP) to investigate how syphilis prevalence varied worldwide in the past century, and what risk factors correlate with this variance.

METHODS

1) A systematic review using PubMed and Google Scholar was conducted to identify countries with published data relating to ASP estimates from before 1952 until the present. Eleven countries were identified (Canada, Denmark, Finland, India, Japan, Norway, Singapore, South Africa, United States of America (USA), United Kingdom (UK) and Zimbabwe). The ASP epidemic curve for each population was depicted graphically. In South Africa and the USA, results are reported separately for the black and white populations. 2) National antenatal syphilis prevalence estimates for 1990 to 1999 and 2008 were taken from an Institute for Health Metrics and Evaluation database on the prevalence of syphilis in low risk populations compiled for the Global Burden of Diseases study and from a recent review paper respectively. National ASPs were depicted graphically and regional median ASPs were calculated for both time periods. 3) Linear regression was used to test for an association between ASP in 1990-1999 and 2008 and four risk factors (efficacy of syphilis screening/treatment, health expenditure, GDP per capita and circumcision prevalence). WHO world regions were included as potential explanatory variables.

RESULTS

In most populations, ASP dropped to under 1% before 1960. In Zimbabwe and black South Africans, ASP was high in the pre-penicillin period, dropped in the post-penicillin period, but then plateaued at around 6% until the end of the 20th century when ASP dropped to just above 1%. In black Americans, ASP declined in the post penicillin period, but plateaued at 3-5% thereafter. ASP was statistically significantly higher in sub-Saharan Africa in 1990-1999 and 2008 than in the other world regions (P < 0.001). On multivariate analysis in both time periods, ASP was only associated with residence in sub-Saharan Africa.

CONCLUSIONS

Further research is necessary to elucidate the reasons for the higher prevalence of syphilis in sub-Saharan Africa.

Strong Country Level Correlation between Syphilis and HSV-2 Prevalence

Background. Syphilis is curable but Herpes Simplex Virus-2 (HSV-2) is not. As a result, the prevalence of syphilis but not HSV-2 may be influenced by the efficacy of national STI screening and treatment capacity. If the prevalence of syphilis and HSV-2 is found to be correlated, then this makes it more likely that something other than differential STI treatment is responsible for variations in the prevalence of both HSV-2 and syphilis. Methods. Simple linear regression was used to evaluate the relationship between national antenatal syphilis prevalence and HSV-2 prevalence in women in two time periods: 1990–1999 and 2008. Adjustments were performed for the laboratory syphilis testing algorithm used and the prevalence of circumcision. Results. The prevalence of syphilis was positively correlated with that of HSV-2 for both time periods (adjusted correlations, 20–24-year-olds: 1990–99: R² = 0.54, P < 0.001; 2008: R² = 0.41, P < 0.001 and 40–44-year-olds: 1990–99: R² = 0.42, P < 0.001; 2008: R² = 0.49, P < 0.001). Conclusion. The prevalence of syphilis and HSV-2 is positively correlated. This could be due to a common set of risk factors underpinning both STIs.

Partner concurrency and HIV infection risk in South Africa

BACKGROUND

The relationship between concurrent sexual partnerships and HIV risk is not fully understood. Evidence on the relationship between partner concurrency (one's sexual partner has another partner) and individual HIV risk is limited. In this study, the relationship between reported sexual partner concurrency and the risk of HIV infection was explored among South Africans.

METHODS

Data from the third South African national HIV survey were used. In this survey, performed in 2008, questionnaires and HIV tests were administered to a nationally representative sample of 15031 persons. Bivariate analysis and multiple logistic regression were used to evaluate the relationship between partner concurrency and HIV serostatus. Spearman's correlation was used to test the association between the prevalence of HIV and partner concurrency by race in women.

RESULTS

The relationship between HIV prevalence and partner concurrency varied by race. At a cross-racial level there was a positive association between HIV prevalence and partner concurrency for women (rho=0.95, p=0.05). Among coloured, white, and Indian persons, HIV prevalence and partner concurrency rates were too low to allow further statistical testing. In the bivariate analysis, black African women who reported partner concurrency had a higher prevalence of HIV (36% (95% confidence interval (CI) 29.7-42.0) vs. 23% (95% CI 19.6-26.1), p<0.001). After controlling for demographic, social, biological, and behavioural variables, the association remained statistically significant (adjusted odds ratio (aOR) 1.4, p=0.04). The association was stronger among 15-29-year-old black African women (aOR 1.8, p=0.03) than among women aged 30 years and older (aOR 1.3, p=0.36).

CONCLUSIONS

These results suggest that partner concurrency may increase the HIV infection risk for black South African women, and in particular, for younger women.

Correlation between Trichomonas vaginalis and Concurrency: An Ecological Study

Objective. There is a large variation in the prevalence of Trichomonas vaginalis (TV) between different countries and between racial groups within countries. Sexual partner concurrency may play a role. We investigate the correlation between the prevalence of sexual partner concurrency and TV prevalence. Methods. Spearman's correlation to assess relationship between TV prevalence in women and point prevalence of concurrency in men in (1) 11 countries with comparable data (concurrency data from WHO Survey and TV prevalence data from Global Burden of Disease estimates) and (2) three racial groups in the United States (Add Health Study). Results. The prevalence of TV and concurrency was positively correlated in the international (rho = 0.84, P = 0.001) and USA study (rho = 1.0, P < 0.001). Conclusion. Prospective longitudinal studies that include measures of partner behavior are required to definitively establish the role of concurrency in the spread of TV.