Biomarker validation of reports of recent sexual activity: results of a randomized controlled study in Zimbabwe

Validity of Partner Reports of Recent Condomless Sex

BACKGROUND

Prostate-specific antigen (PSA), a biomarker of vaginal semen exposure, is less susceptible to bias than self-reported condom use behaviors. We examined the agreement of self-reported recent condomless sex (RCS) within couples and how these reports related to PSA detection.

METHODS

We analyzed data from a study conducted in Vietnam, 2017 to 2020, of 500 different-sex couples using condoms and no other contraceptive method to prevent pregnancy for 6 months. We assessed enrollment and 6-month data from vaginal swabs and questionnaires from both partners. We calculated Prevalence-Adjusted Bias-Adjusted Kappa (PABAK) to evaluate agreement of men's and women's reports. Among couples with detected PSA, we assessed partner concordance of RCS reporting.

RESULTS

At enrollment (n = 499), 79.8% of couples reported no RCS, 16.4% reported RCS, and 3.8% had partner-discordant reports (PABAK, 0.93; 95% confidence interval, 0.91-0.97). At 6 months (n = 472), 91.7% reported no RCS, 5.7% reported RCS, and 2.5% had partner-discordant reports (PABAK, 0.98; 95% confidence interval, 0.96-1.0). Among couples with detected PSA at baseline (11%, n = 55), 36% reported no RCS, 55% reported RCS, and 6% had discordant reports; at 6 months (6.6%, n = 31), 58% reported no RCS, 35% reported RCS, and 3% had discordant reports.

CONCLUSIONS

We observed high agreement regarding condomless sex within couples in a population using condoms as contraception in Vietnam; however, a high proportion of couples with detected PSA had both partners reporting no RCS, indicating that concordant reporting of no RCS does not indicate lack of semen exposure.

A PrEP Demonstration Project Using eHealth and Community Outreach to Justice-Involved Cisgender Women and Their Risk Networks

Women involved in criminal justice systems (WICJ) are a key population at risk for HIV, and pre-exposure prophylaxis (PrEP) is critical for HIV prevention. This project was designed to evaluate the feasibility and acceptability of delivering PrEP via eHealth to WICJ and members of their risk network (RN). We recruited HIV-negative cisgender WICJ index participants (n = 38) and risk network (RN) members (n = 67) using modified respondent-driven sampling. TDF/FTC was initiated for PrEP in participants meeting clinical criteria and dispensed through eHealth using a community-based, low barrier-to-care outreach model. Key steps in the PrEP care continuum were measured over 12 months. Enrolled participants (n = 105) had high current and lifetime justice-involvement and were predominantly cisgender women and non-Hispanic white with a mean age of 40.9y (SD 9.6). Despite most having primary care providers and medical insurance, PrEP awareness was low, and participants experienced high levels of medical, psychiatric, substance use, social, and economic need. Fifty-two participants (50%) were PrEP-eligible, of whom 24 (46%) initiated PrEP. TDF/FTC was safe and well-tolerated throughout follow-up and 13 individuals chose to remain on PrEP following study conclusion. In this novel PrEP demonstration project for WICJ and RN members, despite high medical, psychiatric, and social comorbidity, PrEP was positively received and effectively delivered using a community outreach model via eHealth.Registered on clinicaltrials.gov under trial registration number NCT03293290.

Impact of marital status on risk of HIV in South Africa (2002-2017)

After decades of research, South African women continue to have the highest burden of HIV in the world. The aim of the study is to investigate the impact of marital status on HIV using population and community-level data sources. We included data 13,469 and 5682 South African women who participated to South African HIV behavioural surveys in 2002-2012 and 2017, respectively. HIV prevalence and incidence rates were significantly higher among single/not-cohabiting women compared to those married/cohabiting with a partner in all survey participants (adjusted odds ratio (aOR): 1.60 and 1.58 in 2002-2012 and 2017, respectively). A quarter of the HIV diagnoses were attributed to those who were single/not-cohabiting women (population attributable risk (PAR%): 25% and 24%, respectively). More than 40% of the HIV infections were exclusively associated with single women (PAR%: 42%, 95% CI: 33%, 51%). Our results provided strong evidence for the profound impact of marital status on excess HIV infection rates. Targeting and reaching single/not-cohabiting women with multiple risk factors can potentially play a crucial role in the trajectories of the epidemic.

Comparison of audio computer-assisted self-interview (ACASI) to other survey modes in sexual behaviour surveys in Asia and Sub-Saharan Africa: A systematic literature review (Preprint)

Background

Reliable data about sexual behaviors is fundamental in the prevention and control of HIV, hepatitis, and other sexually transmitted infections. Generally, sexual behaviors are regarded as a sociocultural taboo in Africa and Asia, and this results in biased sexual behavior survey data due to social desirability. Various modes of survey delivery, including audio computer-assisted self-interviews (ACASIs), have been investigated to improve data quality.

Objective

This study aimed to review studies that compared the ACASI mode to other survey modes in sexual behavior surveys in Asia and sub-Saharan Africa to ascertain the impact of survey mode on responses to sexual behavior questions.

Methods

A systematic literature review was conducted according to the Joanna Briggs Institute Manual for Evidence Synthesis. The review protocol was registered at PROSPERO (International Prospective Register of Systematic Reviews). Six databases were searched.

Results

A total of 21 papers were included. The face-to-face interview (FTFI) mode was the survey mode most frequently compared to the ACASI mode. Among the most commonly reported outcome variable groups, ACASI participants were more likely to report sexual behaviors, such as “forced sex,” “multiple partners,” “transactional sex,” and “ever had sex,” as compared to FTFI participants. In addition to the survey mode effect, other factors were found to have had an impact on data quality, for example, participant characteristics, social norms, study design, and data collection setting.

Conclusions

Use of ACASIs for administering sexual behavior surveys among populations in Asia and sub-Saharan Africa demonstrated higher reports for some sexual behaviors than the use of FTFIs. More studies that compare the ACASI mode to other survey modes would improve our understanding of the usefulness of ACASIs in sexual behavior surveys in these regions.

Effectiveness of erectogenic condom against semen exposure among women in Vietnam: Randomized controlled trial

A key barrier to the consistent use of condoms is their negative effect on sexual pleasure. Although sexual pleasure is a primary motivation for engaging in sex and is an integral part of overall sexual health, most programs to improve sexual health operate within a pregnancy and disease-prevention paradigm. A new condom, CSD500 (Futura Medical Developments; Surrey, UK), containing an erectogenic drug was developed for use among healthy couples to improve sexual pleasure by increasing penile firmness, size and erection duration. We conducted a randomized controlled trial to test whether promoting the novel condom CSD500 for improved sexual pleasure is effective in reducing condomless sex compared to the provision of standard condoms with counseling for pregnancy and disease prevention. We randomized 500 adult, heterosexual, monogamous couples in Thanh Hoa province, Vietnam to receive either CSD500 (n = 248) or standard condoms (n = 252). At enrollment and after 2, 4, and 6 months, we interviewed women and sampled vaginal fluid to test for the presence of prostate-specific antigen (PSA), an objective, biological marker of recent semen exposure. We registered the protocol before trial initiation at ClinicalTrials.gov (identifier: NCT02934620). Overall, 11.0% of women were PSA positive at enrollment. The proportion of follow-up visits with PSA-positivity did not differ between the intervention (6.8%) and control arms (6.7%; relative risk, 1.01; 95% confidence interval, 0.66–1.54). Thus, we found no evidence that promoting an erectogenic condom to women in a monogamous, heterosexual relationship in Vietnam reduced their exposure to their partner’s semen. These findings might not hold for other populations, especially those with a higher frequency of condomless sex.

Predicting the Risk of Hiv-1 Acquisition in Rural South Africa Using Geospatial Data

Background

Accurate human immunodeficiency virus (HIV) risk assessment can guide optimal HIV prevention. We evaluated the performance of risk prediction models incorporating geospatial measures.

Methods

We developed and validated HIV risk prediction models in a population-based cohort in South Africa. Individual-level covariates included demographic and sexual behavior measures, and geospatial covariates included community HIV prevalence and viral load estimates. We trained models on 2012–2015 data using LASSO Cox models and validated predictions in 2016–2019 data. We compared full models to simpler models restricted to only individual-level covariates or only age and geospatial covariates. We compared the spatial distribution of predicted risk to that of high incidence areas (≥ 3/100 person-years).

Results

Our analysis included 19 556 individuals contributing 44 871 person-years and 1308 seroconversions. Incidence among the highest predicted risk quintile using the full model was 6.6/100 person-years (women) and 2.8/100 person-years (men). Models using only age group and geospatial covariates had similar performance (women: AUROC = 0.65, men: AUROC = 0.71) to the full models (women: AUROC = 0.68, men: AUROC = 0.72). Geospatial models more accurately identified high incidence regions than individual-level models; 20% of the study area with the highest predicted risk accounted for 60% of the high incidence areas when using geospatial models but only 13% using models with only individual-level covariates.

Conclusions

Geospatial models with no individual measures other than age group predicted HIV risk nearly as well as models that included detailed behavioral data. Geospatial models may help guide HIV prevention efforts to individuals and geographic areas at highest risk.

Interviewing adolescent girls about sexual and reproductive health: a qualitative study exploring how best to ask questions in structured follow-up interviews in a randomized controlled trial in Zambia

Background

Numerous studies have documented inconsistent reporting of sexual behaviour by adolescents. The validity and reliability of self-reported data on issues considered sensitive, incriminating or embarrassing, is prone to social-desirability bias. Some studies have found that Audio Computer-Assisted Self Interviewing (ACASI) that removes the personal interaction involved in face-to-face interviews, decreases item non-response and increases reporting of sensitive behaviours, but others have found inconsistent or contradictory results. To reduce social desirability bias in the reporting of sensitive behaviours, face-to-face interviews were combined with ACASI in a cluster randomized trial involving adolescents in Zambia.

Methods

To explore adolescent girls’ experiences and opinions of being interviewed about sexual and reproductive health, we combined Focus Group Discussions with girl participants and individual semi-structured interviews with teachers. This study was done after the participants had been interviewed for the 6^th time since recruitment. Young, female research assistants who had conducted interviews for the trial were also interviewed for this study.

Results

Respondents explained often feeling shy, embarrassed or uncomfortable when asked questions about sex, pregnancy and abortion face-to-face. Questions on sexual activity elicited feelings of shame, and teachers, research assistants and girls alike noted that direct questions about sexual activities limit what the participant girls may be willing to share. Responding to more indirect questions in relation to the context of a romantic relationship was slightly easier. Efforts by interviewers to signal that they did not judge the participants for their behavior and increased familiarity with the interviewer reduced discomfort over time. Although some appreciated the opportunity to respond to questions on their own, the privacy offered by ACASI also provided an opportunity to give false answers. Answering on tablets could be challenging, but participants were reluctant to ask for assistance for fear of being judged as not conversant with technology.

Conclusion

Strategies to avoid using overly direct language and descriptive words, asking questions within the context of a romantic relationship and a focus on establishing familiarity and trust can reduce reporting bias. For the use of ACASI, considerations must be given to the context and characteristics of the study population.

Numerous studies have found that adolescents may not answer truthfully or consistently when questioned about issues such as sexual activity, abortion and pregnancy. Such issues are considered sensitive, incriminating, or embarrassing, and answers may be influenced by a fear of being misjudged or sanctioned. In an attempt to collect more reliable data on sexual behaviour and childbearing, we combined face-to-face interviews with Audio Computer-Assisted Self Interviewing (ACASI) in a research trial involving adolescents in Zambia. In this study we aimed to explore adolescent girls’ experiences and opinions of being interviewed about sexual and reproductive health when participating in the trial. We combined group discussions with girl participants and individual interviews with teachers. Participants said they felt shy, embarrassed or uncomfortable when asked questions about sex, pregnancy and abortion face-to-face. Teachers, girls and interviewers alike noted that very direct questions limit what the participants may be willing to share. Efforts by interviewers to signal that they did not judge the participants for their behaviour, and repeated interviews with the same interviewer reduced discomfort over time. Some liked ACASI whereas some said it made it easier to give false answers, and answering on electronic tablets could be challenging. To reduce embarrassment and increase the likelihood of honest answers we recommend avoiding overly direct language and descriptive words, and to relate questions about sexual activity to a romantic relationship. Interviewers who are able to establish familiarity and trust can make participants more comfortable.

HIV-1 Nucleic Acids Identify Rectal HIV Exposures in Self-Collected Rectal Swabs, Whereas Y-Chromosome Single Tandem Repeat Mixtures Are Not Reliable Biomarkers of Condomless Receptive Anal Intercourse

BACKGROUND

To focus interventions, biomarkers of HIV-1 exposure could help in identifying subpopulations at highest risk of acquisition. We assessed whether Y-chromosome single tandem repeat (YSTR) mixtures obtained from rectal swabs could serve as a biomarker of condomless receptive anal intercourse (CRAI) among men who have sex with men and transgender women and evaluated the feasibility of detecting HIV-1 virions to assess exposures.

METHODS

Twenty-nine sexually active HIV-seronegative men who have sex with men and one transgender woman from New York City answered on-site and mobile app sexual behavior questionnaires. They were randomized to collecting self-administered rectal swabs every morning or after receptive anal intercourse (RAI). YSTR profiles were assessed from blood sample and swabs; HIV-1 exposure was measured by conducting quantitative polymerase chain reaction in swabs.

RESULTS

After 2 months, the daily mobile survey had 135%-201% more instances of anal sex acts and 170%-193% more RAI than on-site surveys. Daily mobile reporting had 11%-35% less CRAI events than those reported on-site (Pdaily = 0.001; Pper-sex = 0.047). The daily swabbing arm reported less RAI (P < 0.001) and CRAI (P < 0.038) and had 2.95 lower odds of detecting YSTR mixtures (P = 0.021) than the per-sex-event arm. Surprisingly, YSTR detection was not significantly modified by report of bowel movements and lubricant, enema, or condom use. No participant became HIV-1 infected, yet HIV-1 total nucleic acids were detected in 6 independent episodes of CRAI in 2 participants taking pre-exposure prophylaxis.

CONCLUSIONS

YSTR mixtures demonstrated 80% specificity but only 30% sensitivity as a biomarker of CRAI in self-collected rectal swabs. However, detection of HIV-1 exposures in self-collected swabs may help in identifying those needing further HIV risk reduction strategies.

The use of PSA as a biomarker of recent semen exposure in female reproductive health studies

Semen contains potent soluble proteins, bacteria, viruses, activated immune cells as well as anti- and pro-inflammatory cytokines that may influence the inflammatory response and alter microbial composition of the female genital tract. The presence of semen in the female genital mucosa may be a significant confounder that most studies have failed to control for in their analysis. Prostate-specific antigen (PSA), a protein secreted by the prostate into the urethra during ejaculation, is a well-established biomarker of semen exposure. Several studies have demonstrated discordance between self-reports of sexual behavior and the presence of PSA. Recent semen exposure has been shown to promote pro-inflammatory responses, stimulate the recruitment of activated immune cells and decrease Lactobacilli abundance in the female genital mucosa. As a result, it is important to understand the concordance between self-reported consistent condom use and the presence of semen biomarkers. Furthermore, to ensure that the interpretation of data in clinical studies of the immunological and microbial environment in the female genital mucosa are accurate, it is essential to establish whether semen is present in the vaginal fluid. This review explores the impact of semen exposure on the mucosal microenvironment and assesses the use of the PSA as an objective biomarker of semen exposure to reduce reliance on self-reported sexual intercourse.

Recent Semen Exposure Impacts the Cytokine Response and Bacterial Vaginosis in Women

Background

The presence of semen in the vagina from unprotected sex may influence the immune and microbial environment of the female genital tract. Inflammatory cytokine concentrations and BV-associated bacteria in female genital secretions may influence HIV risk, although the effect of recent sexual intercourse on incident BV and the cytokine milieu of cervicovaginal secretions has rarely been measured in previous studies. Here, we investigated the extent to which partner semen impacts the cytokine response and incident BV.

Methods

At baseline, we assessed the recency of semen exposure in menstrual cup supernatants by quantifying prostate specific antigen (PSA) levels using ELISA in 248 HIV-uninfected women at high risk for HIV infection. Luminex was used to measure 48 cytokines in menstrual cup supernatants and vaginal swabs to diagnose BV by Nugent score. Point-of-care screening for Chlamydia trachomatis and Neisseria gonorrhoeae was conducted using GeneXpert while OSOM was used for Trichomonas vaginalis detection. Multivariable models, adjusted for age, sexually transmitted infections, BV, current contraception use and condom use, were used to assess the impact of semen exposure on biomarkers of inflammation and BV.

Results

Presence of PSA, indicating recent semen exposure within 48 hours prior to sampling, was observed in menstrual cup supernatants of 17% (43/248) of women. Of these women, 70% (30/43) had self-reported condom use at their last sex act and 84% (36/43) had BV (Nugent score >7). PSA presence was significantly associated with prevalent BV (Relative Risk (RR), 2.609; 95% Confidence Interval (CI), 1.104 - 6.165; p = 0.029). Furthermore, women with detectable PSA had high median concentrations of macrophage inflammatory protein- beta (MIP-1α, p=0.047) and low median concentration of the stem cell growth factor beta (SCGF-β, p=0.038) compared to those without PSA.

Conclusion

A degree of discordance between self-reports of consistent condom use and PSA positivity was observed. There was also evidence of a relationship between recent semen exposure, BV prevalence and altered cytokine concentrations. These findings suggest that PSA, as a semen biomarker, should be taken into consideration when investigating biological markers in the female genital tract and self-reported condom use in studies on reproductive and sexual health.

The Value of Assessing Self-Reported and Biological Indicators of Outcomes in Evaluating HIV Programs

PURPOSE OF REVIEW

In this manuscript, we present recent findings concerning concordance and discrepancy between biological measures and self-reports of these three outcomes of HIV programs: HIV status, adherence to antiretroviral medications (ARVs) and use of and adherence to pre-exposure prophylaxis medication (PrEP), and condom use/unprotected sex.

RECENT FINDINGS

Recent studies suggest that three successive rapid HIV tests (for those whose first test in positive) might be reasonably inexpensive and valid biological data to collect to combine with self-reports of HIV status, dried blood spots sufficiently affordable to combine with self-reports of adherence to ARVs and use of or adherence to PrEP, and that the discrepancy between self-reports of condom use and biomarkers of unprotected sex may be relatively small in high-income countries. Additional work on assessment of incorrect condom usage and breakage, standardized self-report measures of condom use, and more private data collection methodologies in low-income settings might reduce the recent observed discrepancies even further. Concordance between self-reports of HIV and biomarkers indicating HIV positive status has varied considerably, with much lower rates in low-income countries, where the stigma of HIV is still very high. Recommendation is for combining self-report data with the results of three successive rapid tests for those testing positive. For adherence, again agreement between self-reports and a variety of more objective and/or biological measures is only moderate. Dried blood spots (DBS) may be sufficiently inexpensive in low-resource settings that this may be the best biological method to combine with self-reports. In publications over the last 8 years, the discrepancy between self-reports of condom use and biomarkers for unprotected sex may be even lower than 20% after controlling for other features of the study, particularly in high-income countries. Our results suggest that more careful assessment of incorrect condom use and breakage as reasons other than intentional misreporting should be investigated more carefully and that more private data collection methods such as audio, computer-assisted self-interviewing (ACASI) might be employed more often in low-resource settings to reduce this discrepancy in those settings further. In addition, further analysis of the discrepancy between self-reports of condom use and biomarkers should be conducted of published studies using the correct calculation methods to be more certain of these findings.

Psychosocial Factors, Condomless Sex, and Detectable Viral Load in HIV-Positive Women in Serodiscordant Couples in Nairobi, Kenya

This prospective study of HIV-positive Kenyan women in serodiscordant couples examined relationships between psychosocial factors, viral suppression, and condomless sex. Participants were screened for alcohol use disorders and intimate partner violence (IPV) annually and depressive symptoms every 6 months. Prostate specific antigen (PSA) detection was used as a marker for condomless sex. A total of 151 participants contributed 349 person-years of follow-up. Hazardous/harmful alcohol use was associated with increased risk of detecting PSA in vaginal secretions (aRR 1.99, 95%CI 1.08-3.66, χ2 = 4.85 (1)), while IPV and depression were not. Events representing HIV transmission potential, where there was biological evidence of condomless sex at a visit with a detectable plasma viral load, were observed at 2% of visits. The high prevalence of IPV and association between alcohol use and sexual risk suggest the need for monitoring and support for these conditions as part of comprehensive HIV care for women.

Premarital sex and pregnancy in Greater Jakarta

Social taboos and stigmas around sexuality and non-marital sex in Indonesia have led to substantial underreporting of the prevalence of premarital sex. In this study, we explore underreporting amongst young adults in Greater Jakarta. We use the 2010 Greater Jakarta Transition to Adulthood Survey (GJTAS), a survey of more than 3000 people aged 20–34 years, to derive estimates of underreporting based on discrepancies reported in the timing of marriage, first child birth and first sexual intercourse and sexual activities. Survival and life table analyses are utilised to identify individual and societal predictors of premarital sex and its reporting and to estimate cumulative incidence across young adulthood. The results reveal substantial evidence of underreporting, particularly amongst women, arising from premarital pregnancies. We estimate that the proportion of the female cohort who will engage in premarital sex by the age of 35 years increases from 4.4 to 22% after taking into account evidence of underreporting. Premarital pregnancies and unreported premarital sex is found to be particularly common amongst lower educated people. This raises important questions for policy and research in terms of the provision of information and support for young couples and the methodological implications of substantial underreporting.

PrEP Use Among Female Sex Workers: No Evidence for Risk Compensation

Supplemental Digital Content is Available in the Text.

Little is known about risk compensation among female sex workers (FSW) on HIV pre-exposure prophylaxis (PrEP), and self-report of sexual behaviors is subject to bias.

Early sexual debut and risky sex in young adults: the role of low self-control

BACKGROUND

The purpose of this study was to examine the role of low self-control as a mediator or moderator between early age at sexual debut and risky sexual behavior in young adulthood.

METHODS

Data on 5734 male and female Add Health participants were used. Self-control (waves 1 & 3), age at sexual debut (wave 3) and risky sexual behavior (wave 4) were used in a structural equation modeling framework to assess the relationships of interest.

RESULTS

Approximately 17% of respondents were < 15 years at first sexual intercourse. Among females only, both early age at first intercourse (Parent-report: z = 5.08, p < .001; Self-report: z = 2.05, p < .05) and low self-control at wave 3 (Parent-report: z = 2.30, p < .05; Self-report: z = 2.31, p < .05) mediated the relationship between low self-control at wave 1 and risky sexual behaviors in young adulthood. Similarly in the male-only model, both early age at first intercourse (Parent-report: z = 2.92, p < .01; Self-report: z = 3.04, p < .01) and low self-control at wave 3 (Parent-report: z = 1.99, p < .05; Self-report: z = 3.15, p < .01) mediated the relationship between low self-control and risky sexual behaviors in young adulthood. There was evidence of moderation in the male-only model (- 0.26, p < .01), such that lower impulsivity strengthened the relationship between early sex and risky sex.

CONCLUSIONS

This study confirms the role of executive functions in sexual behaviors and suggests that interventions aimed at improving self-control may be beneficial in reducing risky sexual behavior.

Does schooling protect sexual health? The association between three measures of education and STIs among adolescents in Malawi

While multiple studies have documented shifting educational gradients in HIV prevalence, less attention has been given to the effect of school participation and academic skills on infection during adolescence. Using the Malawi Schooling and Adolescent Study, a longitudinal survey that followed 2,649 young people aged 14-17 at baseline from 2007 to 2013, we estimate the effect of three education variables: school enrolment, grade attainment, and academic skills-numeracy and Chichewa literacy-on herpes simplex virus type 2 (HSV-2) and HIV incidence using interval-censored survival analysis. We find that grade attainment is significantly associated with lower rates of both HSV-2 and HIV among girls, and is negatively associated with HSV-2 but not HIV among boys. School enrolment and academic skills are not significantly associated with sexually transmitted infections (STIs) for boys or girls in our final models. Efforts to encourage school progression in high-prevalence settings in sub-Saharan Africa could well reduce, or at least postpone, acquisition of STIs.

Do women expose themselves to more health-related risks in certain phases of the menstrual cycle? A meta-analytic review

Researchers have increasingly examined the menstrual cycle as a potential source of day-to-day variation in women's cognitions, motivations, and behavior. Within this literature, several lines of research have examined the impact of the menstrual cycle on women's engagement in activities that could negatively affect their health (alcohol and tobacco consumption, sexual behavior, risk recognition). However, findings have been mixed, leaving it unclear whether women may expose themselves to more health-related risks during certain phases of the cycle. We conducted a meta-analysis of 22 published and four unpublished studies (N = 7529, https://osf.io/xr37j/). The meta-analysis revealed shifts across the menstrual cycle in women's sexual behavior with others and risk recognition (higher in ovulatory phase), whereas there was no consistent pattern of difference for alcohol and cigarette consumption. These findings help to clarify the proximate physiological and evolutionary mechanisms underlying women's health-related risk-taking and may inform new interventions.

Coping with risk: Negative shocks, transactional sex, and the limitations of conditional cash transfers

Transactional sex is an important risk-coping mechanism and a leading contributor to the HIV/AIDS epidemic in sub-Saharan Africa. We use data from a conditional cash transfer (CCT) experiment in rural Tanzania designed to incentivize safer sexual behavior by conditioning transfers on testing negative for sexually transmitted infections (STIs). For women, we find that negative shocks measured by food insecurity lead to a 36% increase in STIs and increases in self-reported risky sexual behavior. We find no significant effects of negative shocks on either STIs or self-reported sexual behavior for men. This CCT design did not appear to mitigate the behavioral response to shocks that we document in women. We propose that this finding can be explained by binding credit constraints and the relatively infrequent timing of the CCTs. When women experience a negative shock, cash needs are immediate, while transfers linked to a CCT are paid out in a specific point in time. If women are unable to access credit during a shock, they may resort to transactional sex even if they face monetary incentives to do otherwise.

Daily Vaginal Swabs and Mobile Phone Sex Report for Assessing HIV Virion Exposure Prospectively Among a Cohort of Young Sexually Active Women in South Africa (HVTN 915)

BACKGROUND

Measurements of HIV exposure could help identify subpopulations at highest risk of acquisition and improve the design of HIV prevention efficacy trials and public health interventions. The HVTN 915 study evaluated the feasibility of self-administered vaginal swabs for detection of HIV virions to assess exposure.

METHODS

Fifty 18- to 25-year-old sexually active HIV-seronegative women using contraception were enrolled in Soweto, South Africa. Participants self-administered daily vaginal swabs and answered sexual behavior questions through mobile phone for 90 days. Clinician-administered vaginal swabs, behavioral questionnaires, HIV diagnostic testing, and counseling were performed at 8 clinic visits. Glycogen concentrations assessed adherence to swabbing. Y-chromosome DNA (Yc-DNA) assessed the accuracy of reported condom use. HIV exposure was measured by virion polymerase chain reaction in swabs from 41 women who reported unprotected vaginal sex during follow-up.

RESULTS

Glycogen was detected in 315/336 (93.8%) participant-collected and in all clinician-collected swabs. Approximately 20/39 daily swabs (51.3%) linked to mobile reports of unprotected sex tested positive for Yc-DNA, whereas 10/187 swabs collected after 3 days of abstinence or protected sex (5.3%) had detectable Yc-DNA. No participant became HIV infected during the study; yet, exposure to HIV was detected by nucleic acids in 2 vaginal swabs from 1 participant, collected less than 1 hour after coitus.

CONCLUSION

There was high adherence to daily vaginal swabbing. Daily mobile surveys had accurate reporting of unprotected sex. Detection of HIV in self-collected vaginal swabs from an uninfected participant demonstrated it was possible to measure HIV exposure, but the detection rate was lower than expected.

Transactional Sex among Men Who Have Sex with Men: Differences by Substance Use and HIV Status

Exchanging money, drugs, and other goods for sex has been associated with sexual risk behaviors and increased STIs/HIV. While female sex work is well described, data on men who exchange sex for money or goods are more limited. This paper examined the prevalence and correlates of transactional sex among young men who have sex with men, especially focusing on substance use and HIV status. We conducted a cohort study of 511 participants recruited between August 2014 and December 2017 in Los Angeles, CA. Eligible participants were: (1) between 18 and 45 years of age; (2) male; and (3) if HIV-negative, reported condomless anal intercourse with a male partner in the past 6 months. By design, half were HIV-positive and half HIV-negative. At baseline and semi-annual follow-up visits, computer-assisted self-interviews were used to collect information on demographics, sexual behaviors including transactional sex which was defined as exchange of money, drugs, or a place to stay for anal intercourse. Laboratory testing was conducted for current STI/HIV status. The average age of participants was 31.4 years with 43% identifying as African American, followed by 36% as Hispanic/Latino. The prevalence of recent transactional sex across 1486 study visits was 17% (n = 255), with 74% of those reporting exchanging sex for drugs. The prevalence of transactional sex was higher among those who reported unstable housing (32 vs. 11%; p value < .01), concurrent sexual partnerships (26 vs. 9%; p value < .01), and transgender sex partners (40 vs. 15%; p value < .01). Those who reported receiving money, drugs, or shelter for sex were also more likely to report giving money, drugs, shelter for sex than men who did not report exchange sex (77 vs. 11%; p value < .01). Based on multivariable analyses after adjusting for age and race/ethnicity, HIV viral load was independently associated with transactional sex [adjusted odds ratio (AOR) = 1.4; 95% confidence interval (CI) 1.1-1.7) per log₁₀ increase]. Additionally, those testing positive for an STI were nearly twice as likely to report transactional sex as compared to those without STIs (AOR = 1.9; 95% CI 1.2-3.5). These findings underscore the relatively high prevalence of transactional sex and its potential role in ongoing HIV transmission among this cohort of high-risk HIV-negative and HIV-positive men who have sex with men.

Inconsistent Use of Condom in Italian HIV-Serodiscordant Heterosexual Couples as Revealed by the Detection of Y Chromosomal (Yc) DNA in Vaginal Swabs

Introduction:

The prevention of transmission of HIV infection is based on the regular and correct use of condom and studies on transmission rates are generally based on the self-report of condom use.

However, consistent data on different population suggest that this often leads to overreporting possibly due to social desirability. In addition, self-report of condom use does not consider improper use or breakage.

Methods:

Vaginal biomarkers were proposed to detect exposure to semen and among these detection of chromosome Y DNA (Yc) appeared promising in different research settings.

Here, we searched for Yc in vaginal swabs of 33 Italian women, engaged in a regular heterosexual relationship with a HIV serodiscordant partner and reporting a regular use of condom during sexual intercourses.

Results & Discussion:

In 10 (30.3%) women Yc was detected, especially if the infected partner was male and if the couple did not have sons. This is confirmed in Italian heterosexual women and is already demonstrated in other populations: behavioural counselling is not always a valid tool and the self-reported use of condom is not fully reliable.

Conclusion:

Further studies could help in the future to individuate more effective preventive strategies for both HIV and sexually transmitted infections.

Biological Validation of Self-Reported Unprotected Sex and Comparison of Underreporting Over Two Different Recall Periods Among Female Sex Workers in Benin

Background

Self-reported unprotected sex validity is questionable and is thought to decline with longer recall periods. We used biomarkers of semen to validate self-reported unprotected sex and to compare underreporting of unprotected sex between 2 recall periods among female sex workers (FSW).

Methods

At baseline of an early antiretroviral therapy and pre-exposure prophylaxis demonstration study conducted among FSW in Cotonou, Benin, unprotected sex was assessed with retrospective questionnaires, and with vaginal detection of prostate-specific antigen (PSA) and Y-chromosomal deoxyribonucleic acid (Yc-DNA). Underreporting in the last 2 or 14 days was defined as having reported no unprotected sex in the recall period while testing positive for PSA or Yc-DNA, respectively. Log-binomial regression was used to compare underreporting over the 2 recall periods.

Results

Unprotected sex prevalence among 334 participants was 25.8% (50.3%) according to self-report in the last 2 (or 14) days, 32.0% according to PSA, and 44.3% according to Yc-DNA. The proportion of participants underreporting unprotected sex was similar when considering the last 2 (18.9%) or 14 days (21.0%; proportion ratio = 0.90; 95% confidence interval, 0.72–1.13). Among the 107 participants who tested positive for PSA, 19 (17.8%) tested negative for Yc-DNA.

Conclusions

Underreporting of unprotected sex was high among FSW but did not seem to be influenced by the recall period length. Reasons for discrepancies between PSA and Yc-DNA detection, where women tested positive for PSA but negative for Yc-DNA, should be further investigated.

Contraceptive use and the risk of sexually transmitted infection: systematic review and current perspectives

Purpose

Evidence on the association between contraceptive use and risk of sexually transmitted infections (STIs) and bacterial vaginosis (BV) is lacking, with few prospective studies. We systematically reviewed the last 10 years' evidence on the association between contraception and STI/BV, building on the most recent systematic reviews published in 2006 and 2009.

Methods

We searched the MEDLINE and POPLINE databases for peer-reviewed articles p ublished between January 1, 2008 and January 31, 2018 reporting prospective studies that assessed the association between contraceptive use and incident STI and/or incident or recurrent BV.

Results

We identified 33 articles that evaluated combined oral contraceptives (COC), depot medroxyprogesterone acetate (DMPA), the copper intrauterine device (Cu-IUD), the levonorgestrel intrauterine system (LNG-IUS) and other methods. The strength of the evidence for many specific contraceptive method/STI associations is limited by few prospective studies with comparably defined exposures and outcomes. Available data suggest no association of COCs and Neisseria gonorrhoeae, Trichomonas vaginalis, HSV-2 or syphilis, and mixed evidence on the association with HPV, Chlamydia trachomatis, and BV. For DMPA, none of the studies identified found an association with N. gonorrhoeae or syphilis, and data on C. trachomatis, T. vaginalis, HPV and BV were mixed. Two large studies showed a highly clinically significant increased risk of HSV-2 infection with DMPA use. Data on the effect of Cu-IUD and the LNG-IUS on the acquisition of C. trachomatis, N. gonorrhoeae and T. vaginalis are sparse, and data on HPV and BV are mixed.

Conclusion

Few data are available from prospective studies, including randomized trials, to draw strong conclusions about the relationships between contraceptive methods and specific STIs. The overall evidence on the association between contraceptive use and STI/BV risk is limited by the lack of any randomized trials, few published prospective studies designed to analyze these associations, wide variability in exposure definitions and comparator groups, potential for confounding due to inaccurate sexual behavior data, differential confounder adjustment and differences in study populations and sizes. Despite these limitations, new evidence is supportive of a significantly increased risk of HSV-2 infection among DMPA users which warrants additional research to better understand this association.

Relative patterns of sexual activity and fertility among HIV positive and negative women-Evidence from 46 DHS

Objectives

Projections of fertility of HIV positive women as ART scales up are needed to plan prevention of mother-to-child transmission (PMTCT) services. We describe differences in exposure to pregnancy between HIV positive and HIV negative women by age, region and national ART coverage to evaluate the extent to which behavioural differences explain lower fertility among HIV positive women and assess whether exposure to pregnancy has changed with antiretroviral treatment (ART) scale-up.

Methods

We analysed 46 nationally representative household surveys in sub-Saharan Africa conducted between 2003 and 2015 to estimate risk of exposure to recent sex and pregnancy of HIV positive and HIV negative women by age using a log binomial model. We tested for regional and urban/rural differences and associations with national ART coverage. We estimated an adjusted fertility rate ratio of HIV positive to HIV negative women adjusting for differences in exposure to pregnancy.

Results

Exposure to pregnancy differs significantly between HIV positive and negative women by age, modified by region. Younger HIV positive women have a higher exposure to pregnancy than HIV negative women and the opposite is true at older ages. The switch occurs at 25–29 for rural women and 30–34 for urban women. There was no evidence that exposure to pregnancy of HIV positive women have changed as national ART coverage increased. The inferred rate of fecundity of HIV positive women when adjusted for differences in exposure to pregnancy were lower than unadjusted fertility rate ratios in women aged 20–29 and 20–24 in urban and rural areas respectively varying between 0.6 and 0.9 over regions.

Discussion

The direct effects of HIV on fertility are broadly similar across ages, while the dramatic age gradient that has frequently been observed is largely attributable to variation in relative sexual exposure by age.

Parents' reactions to testing for herpes simplex virus type 2 as a biomarker of sexual activity in Botswana junior secondary school students

Background Use of sexual activity biomarkers in HIV prevention trials has been widely supported to validate self-reported data. When such trials involve minors, researchers may face challenges in obtaining parental buy-in, especially if return of results procedures uphold the confidentiality and privacy rights of minors and preclude parental access to test results. In preparation for a randomised controlled trial (RCT) with junior secondary school (JSS) students in Botswana, a formative assessment was conducted to assess parents' opinions and concerns about testing for herpes simplex virus type 2 (HSV-2) (biomarker of sexual activity) as part of the RCT.

METHODS

Six focus groups were held with parents (n=32) of JSS students from urban, peri-urban and rural communities. Parents were asked their opinions of students being tested for HSV-2 and procedures for blood sample collection and return of results.

RESULTS

Overall, parents were supportive of HSV-2 testing, which they thought was a beneficial sexual health resource for adolescents and parents, and a motivation for parent-child communication about HSV-2, sexual activity and sexual abuse. Some parents supported the proposed plan to disclose HSV-2 test results to adolescents only, citing the importance of adolescent privacy and the possibility of HSV-2 positive adolescents being stigmatised by family members. Conversely, opposing parents requested parental access to results. These parents were concerned that adolescents may experience distress following a positive result and withhold this information thereby reducing parents' abilities to provide support. Parents were also concerned about support for victims of sexual abuse.

CONCLUSION

Although the present study demonstrates that parents can be accepting of sexual activity biomarker testing of adolescents, more research is needed to identify best approaches for returning test results.

Measuring sexual behaviour in Malawi: a triangulation of three data collection instruments

BACKGROUND

There is a need for valid approaches to measure sexual interactions to assess the impact of behavioural interventions and to predict the impact of behaviour changes. Different methods of asking about sexual behaviour often yield conflicting answers and men often report higher levels of heterosexual activity than women. To better understand self-reported sexual behaviour data and how best to collect it, we analyzed data collected as part of a larger project (ST IMPACTS) on the social and behavioural impact of introducing community-level HIV self-testing (HIVST) with counseling (semi-supervised with pre- and generic post-test counseling provided on delivery or collection of test kits) in an urban Malawian setting.

METHODS

Information on sexual behaviour was collected from HIV self-testers over a three-month period. Three different methods were used: retrospective face-to-face interviews (FTFI); audio computer assisted self-interviews (ACASI) and a prospective coital diary. Both retrospective instruments were used before and after the three-month study period. Frequency and cross-tabulation, as well as scatterplots, were used for exploratory analyses. Chi-square tests were used to test for differences in proportions. Spearman's correlation coefficient was used to explore associations between both continuous and ordinal variables and Wilcoxon's paired sample and Mann-Whitney test was used to test for differences in such variables or between variables.

RESULTS

There was reasonable agreement between the two retrospective methods although both yielded inconsistent answers e.g. with lower reported numbers of life-time sexual partners at the end than at the beginning of the study period. The diary method elicited higher reported levels of sex with multiple partners than both retrospective instruments which may be due to inadequate recall. Over the study period 37.4% of men and 19.7% of women reported multiple sexual partners using the diary. There was no clear relationship between reported sexual behaviour and HIV status (prevalence 9.6%).

CONCLUSIONS

Diaries may therefore have higher validity for sensitive behaviour reporting and thus be the preferred method in similar African contexts in measuring sexual behaviours.

Punto Seguro: A Randomized Controlled Pilot Using Conditional Economic Incentives to Reduce Sexually Transmitted Infection Risks in Mexico

Randomized controlled pilot evaluated effect of conditional economic incentives (CEIs) on number of sex partners, condom use, and incident sexually transmitted infections (STIs) among male sex workers in Mexico City. Incentives were contingent on testing free of new curable STIs and/or clinic attendance. We assessed outcomes for n = 227 participants at 6 and 12 months (during active phase with incentives), and then at 18 months (with incentives removed). We used intention-to-treat and inverse probability weighting for the analysis. During active phase, CEIs increased clinic visits (10-13 percentage points) and increased condom use (10-15 percentage points) for CEI groups relative to controls. The effect on condom use was not sustained once CEIs were removed. CEIs did not have an effect on number of partners or incident STIs. Conditional incentives for male sex workers can increase linkage to care and retention and reduce some HIV/STI risks such as condomless sex, while incentives are in place.

Nonpaternity and Half-Siblingships as Objective Measures of Extramarital Sex: Mathematical Modeling and Simulations

Background

Understanding the epidemiology of HIV and other sexually transmitted infections (STIs) requires knowledge of sexual behavior, but self-reported behavior has limitations. We explored the reliability and validity of nonpaternity and half-siblings ratios as biomarkers of current and past extramarital sex.

Methods

An individual-based Monte Carlo simulation model was constructed to describe partnering and conception in human populations with a focus on Sub-Saharan Africa (SSA). The model was parameterized with representative biological, behavioral, and demographic data.

Results

Nonpaternity and half-siblings ratios were strongly correlated with extramarital sex, with Pearson correlation coefficients (PCC) of 0.79 (95% CI: 0.71–0.86) and 0.77 (0.68–0.84), respectively. Age-specific nonpaternity ratios correlated with past extramarital sex at time of conception for different scenarios: for example, PCC, after smoothing by moving averages, was 0.75 (0.52–0.89) in a scenario of steadily decreasing nonmarital sex and 0.39 (0.01–0.73) in a scenario of transient drops in nonmarital sex. Simulations assuming self-reported levels of extramarital sex from Kenya yielded nonpaternity levels lower than global nonpaternity data, suggesting sizable underreporting of extramarital sex.

Conclusions

Nonpaternity and half-siblings ratios are useful objective measures of extramarital sex that avoid limitations in self-reported sexual behavior.

Prostate-specific antigen concentration in vaginal fluid after exposure to semen

OBJECTIVE

Prostate-specific antigen (PSA) is the best established biomarker of semen exposure. PSA in vaginal fluid returns to pre-exposure concentrations within 24-48 h, but the speed of decay during the first 10 h is unknown. We sought to determine how fast PSA concentrations decline during the first 10 h after exposure to semen.

STUDY DESIGN

Women in the 50 enrolled couples were intravaginally inoculated with 10, 20, 100 and 200 μl of their partner's semen and then collected vaginal swabs immediately after, 30 min, 4 h and 10 h after exposure. Forty-seven sets of samples were tested for PSA. Mixed linear models for repeated measures examined the association between log-transformed PSA values and sampling time and semen exposure volume. Sensitivity analyses excluded data from nonabstainers. Fixed-effect estimates from the statistical models were graphed.

RESULTS

PSA values were highest at 200 μl inoculation volumes and at earlier post-exposure time points, then decline steadily. The lowest inoculation volume (10 μl) corresponded to the smallest concentration of PSA throughout the post-inoculation time points. Average PSA levels return to clinically non-detectable levels within 10 h only at the lowest semen exposures. The PSA decay curve assumes a very similar profile across all time points and semen amounts.

CONCLUSIONS

The PSA decay curve is similar for varying semen exposure volumes, with average PSA concentrations remaining above clinical thresholds 10 h after exposure at all except the very smallest semen exposure levels. PSA is an objective marker of recent exposure to semen, permitting such detection with high accuracy.

IMPLICATIONS

This study clarifies how PSA values vary at different semen exposure levels and time points during the first 10 h post-exposure. Future contraceptive studies that use PSA as a semen biomarker will be better informed about PSA concentrations at different sampling times and exposure amounts.

Vaginal Prostate Specific Antigen (PSA) Is a Useful Biomarker of Semen Exposure Among HIV-Infected Ugandan Women

The practical feasibility of using prostate specific antigen (PSA) as a biomarker of semen exposure was examined among HIV-infected Ugandan women. Vaginal fluids were obtained with self-collected swabs and a qualitative rapid test (ABAcard^®p30) was used to detect PSA. Trained laboratory technicians processed samples on-site and positive PSA tests were compared to self-reported unprotected vaginal sex (UVS) in the last 48 h. A total of 77 women submitted 126 samples for PSA testing at up to three study visits. Of these samples, 31 % (n = 39/126) were PSA positive, and 64 % (n = 25/39) of the positive PSA samples were accompanied by self-report of no UVS at the study visit the PSA was collected. There were no reported difficulties with specimen collection, storage, or processing. These findings provide preliminary data on high levels of misreported UVS among HIV-infected Ugandan women using practically feasible methods for PSA collection and processing.

Objective Measurement of Inaccurate Condom Use Reporting Among Women Using Depot Medroxyprogesterone Acetate for Contraception

Observational analyses have suggested that women using the injectable contraceptive depot medroxyprogesterone acetate (DMPA) may have heightened risk of acquiring HIV. However, those analyses were potentially confounded by sexual behavior, with possible differential condom use and reporting by women using DMPA versus no contraception. In a cross-sectional study, we measured the presence of a biomarker of recent condomless sex (Y chromosomal [Yc] DNA) in vaginal swabs from HIV-uninfected African women who had an HIV-infected partner and reported 100 % condom use. Half of the samples tested were from women reporting DMPA and half were from women using no contraception. Among 428 specimens tested (213 from DMPA users and 215 from women using no contraception), 32.0 % had Yc DNA detected, with a mean of 193 copies/10,000 human cells (range 0.1-8201). The frequency of detection did not differ by contraceptive use: 34.2 % of DMPA users versus 29.8 % of women using no contraception, adjusted odds ratio 1.3 (95 % confidence interval 0.9-2.0). These results suggest that inaccurate reporting of condom use by DMPA users may not account for the heightened risk of HIV acquisition among DMPA users in some observational studies.

Prevalence and risk factors associated with STIs among women initiating contraceptive implants in Kingston, Jamaica

BACKGROUND

There is limited information on rates of STIs in Jamaica due to syndromic management and limited aetiological surveillance. We examined the prevalence of Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG) and Trichomonas vaginalis (TV) and characteristics associated with STIs among sexually active women who participated in a randomised trial of a progestin implant initiation in Jamaica (the Sino-Implant Study (SIS)).

METHODS

SIS was a randomised trial conducted in Kingston, Jamaica, from 2012 to 2014 to evaluate whether initiation of the Sino-Implant (II) led to more unprotected sex among women ages 18-44 years. Data collected included self-reported demographic, sexual behaviour information; and vaginal swabs collected at baseline, 1-month and 3-month follow-up visits for a biomarker of recent semen exposure (prostate-specific antigen (PSA)) and for STIs. We examined associations between STIs and PSA, demographics, sexual behaviour and insertion of an implant, with a repeated-measures analysis using generalised estimating equations (SAS Institute, V.9.3).

RESULTS

Remnant vaginal swabs from 254 of 414 study participants were tested for STIs. At baseline, 29% of participants tested for STIs (n=247) had laboratory-confirmed CT, 5% NG, 23% TV and 45% any STI. In a repeated-measures analysis adjusted for study arm (immediate vs delayed implant insertion), those with PSA detected did not have an increased prevalence of any STI (prevalence ratio (PR)=1.04 (95% CI 0.89 to 1.21)), whereas prevalence decreased for each 1-year increase in age (PR=0.98 (95% CI 0.97 to 0.99)). Immediate implant insertion was not associated with increases in any STI in subsequent visits (PR=1.09 (95% CI 0.94 to 1.27)).

CONCLUSIONS

Although the prevalence of laboratory-confirmed STIs was high, the immediate initiation of a contraceptive implant was not associated with higher STI prevalence rates over 3 months.

TRIAL REGISTRATION NUMBER

NCT01684358.

Sexual Risk and Intravaginal Practice Behavior Changes During Pregnancy

Data suggest that pregnant women in some settings have high prevalence of HIV and other sexually transmitted infections (STI). We examined changes in sexual risk behaviors and intravaginal practices during pregnancy that may contribute to HIV and STI incidence using data from the Methods for Improved Reproductive Health in Africa study conducted in South Africa and Zimbabwe 2003-2006. We used a crossover design and modified Poisson regression to compare behaviors among HIV negative women 18-45 years during pregnant and non-pregnant periods. Among the 4802 women <45 years at enrollment, 483 (10.1 %) had a pregnancy and were included in the analysis. Compared to non-pregnant periods, pregnancy was associated with fewer than 3 sex acts per week (adjusted risk ratio [ARR] 0.89; 95 % CI 0.79-0.99) but more sex acts without condoms (ARR 1.32; 95 % CI 1.15-1.51). Pregnancy was also associated with decreased reporting of other sexual risk behaviors including any anal sex, multiple sexual partners, and/or sex in exchange for drugs or money. Women also reported less intravaginal wiping during pregnancy (ARR 0.84; 95 % CI 0.76-0.93). We found pregnancy decreased sexual activity and some high-risk sexual behaviors but increased the risk of sex without a condom.

Biomarker validation of self-reported sex among middle-aged female sex workers in China

PURPOSE

The objective of this study was to examine information bias arising from self-reported sexual activity and its association with syphilitic infections among female sex workers (FSWs) aged 35 years and older in China.

METHODS

A questionnaire was administered to 1245 middle-aged FSWs. Respondents self-reported sexual intercourse in the past 48 hours. The prostate-specific antigen test was used to verify self-reported sexual activity. FSWs were considered discordant if they indicated no sexual intercourse in the past 48 hours on the questionnaire and had a positive prostate-specific antigen test. Logistic regression was used to assess the associations between discordance and syphilis.

RESULTS

Three hundred twenty FSWs self-reported no engagement in sexual intercourse in the past 48 hours. One-fourth of respondents (25%) were discordant. Twenty-two percent and 35.8% of discordant FSWs tested positive for active and prevalent syphilis, respectively. After adjusting for confounders, discordant FSWs had 3.8 times the odds of active syphilis (95% confidence interval: 1.52-9.30) and 2.6 times the odds of prevalent syphilis (95% confidence interval: 1.37-5.02), compared with concordant FSWs.

CONCLUSIONS

FSWs who had active or prevalent syphilis were more likely to be discordant. Data collected via self-reported questionnaire may not be a valid tool to assess sexual behavior.

Sustained effect of couples' HIV counselling and testing on risk reduction among Zambian HIV serodiscordant couples

Background

We present temporal trends in self-reported and biological markers of unprotected sex and sex with concurrent partners in discordant couples receiving couples' voluntary HIV counselling and testing (CVCT).

Methods

Heterosexual Zambian HIV-serodiscordant couples were enrolled into longitudinal follow-up in an open cohort (1994–2012). Multivariable Anderson-Gill models explored predictors of self-report and biological indicators of unprotected sex within (including sperm on a vaginal swab, incident pregnancy or incident linked HIV infection) and outside (including self-report, STI and unlinked HIV infection) the union. Measures of secular trends in baseline measures were also examined.

Results

At enrolment of 3049 couples, men were 35 years old on average, women were 29 years, and couples had been together for an average of 7 years. M+F− couples reported an average of 16.6 unprotected sex acts in the 3 months prior to enrolment (pre-CVCT), dropping to 5.3 in the >0–3 month interval, and 2.0 in >6 month intervals (p-trend <0.001). Corresponding values for M−F+ couples were 22.4 unprotected sex acts in the 3 months prior enrolment, dropping to 5.2 in the >0–3 month interval, and 3.1 in >6 month intervals (p-trend <0.001). Significant reductions in self-report and biological markers of outside partners were also noted. Predictors of unprotected sex between study partners after CVCT included prevalent pregnancy (adjusted HR, aHR=1.6–1.9); HIV+ men being circumcised (aHR=1.2); and HIV− women reporting sex with outside partners (aHR=1.3), alcohol (aHR=1.2), injectable (aHR=1.4) or oral (aHR=1.4) contraception use. Fertility intentions were also predictive of unprotected sex (aHR=1.2–1.4). Secular trends indicated steady declines in reported outside partners and STIs.

Conclusion

Reductions in self-reported unprotected sex after CVCT were substantial and sustained. Reinforced risk-reduction counselling in pregnant couples, couples desiring children and couples with HIV− women having outside partners or using alcohol or injectable or oral contraception are indicated.

Lost in Translation: Language, Terminology, and Understanding of Penile-Anal Intercourse in an HIV Prevention Trial in South Africa, Uganda, and Zimbabwe

Despite efforts to use culturally appropriate, understandable terms for sexual behavior in HIV prevention trials, the way in which participants interpret questions is underinvestigated and not well understood. We present findings from qualitative interviews with 88 women in South Africa, Uganda, and Zimbabwe who had previously participated in an HIV prevention trial. Findings suggested that participants may have misinterpreted questions pertaining to penile-anal intercourse (PAI) to refer to vaginal sex from behind and subsequently misreported the behavior. Three key issues emerge from these findings: first, the underreporting of socially stigmatized sexual behaviors due to social desirability bias; second, the inaccurate reporting of sexual behaviors due to miscomprehension of research terms; and third, the ambiguity in vernacular terms for sexual behavior and lack of acceptable terms for PAI in some languages. These findings highlight methodological challenges around developing clear and unambiguous definitions for sexual behaviors, with implications not only for clinical trials but also for clinical practice and sexual risk assessment. We discuss the challenges in collecting accurate and reliable data on heterosexual PAI in Africa and make recommendations for improved data collection on sensitive behaviors.

PrEP implementation research in Africa: what is new?

INTRODUCTION

Of the two million new HIV infections in adults in 2014, 70% occurred in sub-Saharan Africa. Several African countries have already approved guidelines for pre-exposure prophylaxis (PrEP) for individuals at substantial risk of HIV as part of combination HIV prevention but key questions remain about how to identify and deliver PrEP to those at greatest need. Throughout the continent, individuals in sero-discordant relationships, and members of key populations (sex workers, men who have sex with men (MSM), transgender women and injection drug users) are likely to benefit from the availability of PrEP. In addition, adolescent girls and young women (AGYW) are at substantial risk in some parts of the continent. It has been estimated that at least three million individuals in Africa are likely to be eligible for PrEP according to WHO's criteria. Tens of demonstration projects are planned or underway across the continent among a range of countries, populations and delivery settings.

DISCUSSION

In each of the target populations, there are overarching issues related to (i) creating demand for PrEP, (ii) addressing supply-side issues and (iii) providing appropriate and tailored adherence support. Critical for creating demand for PrEP is the normalization of HIV prevention. Community-level interventions which engage opinion leaders as well as empowerment interventions for those at highest risk will be key. Critical to supply of PrEP is that services are accessible for all, including for stigmatized populations. Establishing accessible integrated services provides the opportunity to address other public health priorities including the unmet need for HIV testing, contraception and sexually transmitted infections treatment. National policies need to include minimum standards for training and quality assurance for PrEP implementation and to address supply chain issues. Adherence support needs to recognize that social and structural factors are likely to have an important influence. Combining interventions that build self-efficacy, empowerment and social cohesion, with evidence-based individualized adherence support for PrEP, are most likely to be effective.

CONCLUSIONS

Efficacy of tenfovir-based PrEP is proven but many issues related to implementation remain unclear. Here, we have summarized some of the important implementation questions that need to be assessed as PrEP is rolled out across Africa.

Social Desirability Response Bias and Other Factors That May Influence Self-Reports of Substance Use and HIV Risk Behaviors: A Qualitative Study of Drug Users in Vietnam

The accuracy of self-report data may be marred by a range of cognitive and motivational biases, including social desirability response bias. The current study used qualitative interviews to examine self-report response biases among participants in a large randomized clinical trial in Vietnam. A sample of study participants was reinterviewed. The vast majority reported being truthful and emphasized the importance of rapport with the study staff for achieving veridical data. However, some stated that rapport may lead to under reporting of risk behaviors in order not to disappoint study staff. Other factors that appeared to influence accuracy of self-reports include fear that the information may be divulged, desire to enroll in the study, length of the survey, and memory. There are several methods that can be employed to reduce response biases, and future studies should systematically address response bias and include methods to assess whether approaches and survey items are effective in improving accuracy of self-report data.

Using Qualitative Methods to Validate and Contextualize Quantitative Findings: A Case Study of Research on Sexual Behavior and Gender-Based Violence Among Young Swazi Women

Nesting qualitative data collection methods within quantitative studies improves results by assessing validity and providing depth and context. Using data from 3 sources from Swaziland, we triangulate qualitative and quantitative findings to highlight how different methodologies produce discrepant data regarding risky sexual behaviors among young women. We found that women reported similar numbers of lifetime sex partners in all sources, but the proportion reporting multiple and concurrent partnerships was several times higher in qualitative interviews. In addition, qualitative data can provide deeper understanding of how participants, such as those experiencing gender-based violence, understood the experiences behind the quantitative statistics.

A Prospective Cohort Study of Intimate Partner Violence and Unprotected Sex in HIV-Positive Female Sex Workers in Mombasa, Kenya

We conducted a prospective cohort study to test the hypothesis that intimate partner violence (IPV) is associated with unprotected sex in HIV-positive female sex workers in Mombasa, Kenya. Women completed monthly visits and quarterly examinations. Any IPV in the past year was defined as ≥1 act of physical, sexual, or emotional violence by the current or most recent emotional partner ('index partner'). Unprotected sex with any partner was measured by self-report and prostate specific antigen (PSA) test. Recent IPV was associated with significantly higher risk of unprotected sex (adjusted relative risk [aRR] 1.91, 95 % CI 1.32, 2.78, p = 0.001) and PSA (aRR 1.54, 95 % CI 1.17, 2.04, p = 0.002) after adjusting for age, alcohol use, and sexual violence by someone besides the index partner. Addressing IPV in comprehensive HIV programs for HIV-positive women in this key population is important to improve wellbeing and reduce risk of sexual transmission of HIV.

Bias in Self-Reported Condom Use: Association Between Over-Reported Condom Use and Syphilis in a Three-Site Study in China

This study examined over-reporting bias in self-reported condom use and assessed its association with syphilis. A survey was conducted among 1245 female sex workers (FSWs) in three cities in China. Respondent's over-reported condom use was defined as reporting no unprotected sex for the past 24 h but testing positive for prostate specific antigen. The proportion of prevalent syphilis and active syphilis was 23 and 10 % respectively among FSWs. The proportion of over-reported condom use with sex clients only was 27-45 % among the three study sites. The proportion of over-reported condom use with all sex partners (clients, husbands, or boyfriends) was 26-46 %. FSWs who had active or prevalent syphilis were more likely to over report condom use. Self-reported condom use may not be a valid tool to measure the efficacy of HIV/STI intervention because the bias is associated with the outcome measure, i.e., syphilis.

Assessment of the vaginal residence time of biomarkers of semen exposure

OBJECTIVE

The primary objective of this pilot study is to determine and compare the residence time in the vagina of biomarkers of semen exposure for up to 15 days post exposure. The biomarkers are prostate-specific antigen (PSA), Y chromosome DNA, the sex determining region of the Y chromosome (SRY) and testis-specific protein Y-encoded 4 (TSPY4). The secondary objectives are to determine if biomarker concentrations differed between intercourse and inoculation groups, to establish whether the sampling frequency post exposure affected biomarker concentrations and decay profile and to determine if biomarker concentrations in vaginal swabs obtained by the participant at home were similar to swabs obtained by the nurse in the clinic.

STUDY DESIGN

We randomized healthy women to unprotected intercourse (n=17) versus vaginal inoculation with the male partner's semen in the clinic (n=16). Women were then further randomized to have vaginal swabs obtained at either 7 or 4 time points after semen exposure, up to 15 days post exposure, either obtained at home by the participant or in the clinic by the research nurse.

RESULTS

PSA and SRY were markers of recent semen exposure. TSPY4 was detectable in approximately 50% of participants at 15 days post exposure. Unprotected intercourse resulted in significantly higher concentrations of select biomarkers. Sampling frequency and home versus clinic sampling had no significant effect on biomarker concentrations.

CONCLUSIONS

Objective biomarkers of recent or distant semen exposure may have great utility for verifying protocol compliance in a variety of clinical trials.

Antiretroviral therapy and demand for HIV testing: Evidence from Zambia

This paper examines the effects of antiretroviral therapy (ART) on demand for HIV testing and of ART-induced testing on demand for risky sexual behavior. I provide a model of sexual behavior decision-making under uncertainty and estimate the structural parameters of the model using nationally representative survey data from Zambia on HIV testing decisions before and after the introduction of ART. The empirical results indicate that although the introduction of ART appears to have increased HIV testing rates by upwards of 50 percent, the ART allocation process may have limited the prevention benefit of ART-induced testing. Simulation results show that eliminating this prevention inefficiency while holding the supply of ART constant would increase the prevention impact of ART-induced testing more than four-fold. More generally, the analysis indicates that existing studies which examine "universal" testing or quasi-experimental testing programs understate the efficacy of standard voluntary counseling and testing programs.

The Incidence of Human Papillomavirus in Tanzanian Adolescent Girls Before Reported Sexual Debut

PURPOSE

Acquisition of human papillomavirus (HPV) in women occurs predominantly through vaginal sex. However, HPV has been detected in girls reporting no previous sex. We aimed to determine incidence and risk factors for HPV acquisition in girls who report no previous sex in Tanzania, a country with high HPV prevalence and cervical cancer incidence.

METHODS

We followed 503 adolescent girls aged 15-16 years in Mwanza, Tanzania, with face-to-face interviews and self-administered vaginal swabs every 3 months for 18 months; 397 girls reported no sex before enrollment or during follow-up; of whom, 120 were randomly selected. Samples from enrollment, 6-, 12-, and 18-month visits were tested for 37 HPV genotypes. Incidence, clearance, point prevalence, and duration of any HPV and genotype-specific infections were calculated and associated factors were evaluated.

RESULTS

Of 120 girls who reported no previous sex, 119 were included, contributing 438 samples. HPV was detected in 51 (11.6%) samples. The overall incidence of new HPV infections was 29.4/100 person-years (95% confidence interval: 15.9-54.2). The point prevalence of vaccine types HPV-6,-11,-16, and -18 was .9%, .9%, 2.0%, and 0%, respectively. Spending a night away from home and using the Internet were associated with incident HPV, and reporting having seen a pornographic movie was inversely associated with HPV incidence.

CONCLUSIONS

Incident HPV infections were detected frequently in adolescent girls who reported no previous sex over 18 months. This is likely to reflect under-reporting of sex. A low-point prevalence of HPV genotypes in licensed vaccines was seen, indicating that vaccination of these girls might still be effective.

Divergent adherence estimates with pharmacokinetic and behavioural measures in the MTN-003 (VOICE) study

INTRODUCTION

In the Microbicide Trial Network MTN-003 (VOICE) study, a Phase IIB pre-exposure prophylaxis trial of daily oral or vaginal tenofovir (TFV), product adherence was poor based on pharmacokinetic (PK) drug detection in a random subsample. Here, we sought to compare behavioural and PK measures of adherence and examined correlates of adherence misreporting.

METHODS

We included participants with PK and behavioural data from VOICE random subsample. Behavioural assessments included face-to-face interviews (FTFI), audio computer-assisted self-interviewing (ACASI) and pharmacy-returned product counts (PC). TFV concentrations < 0.31 ng/mL in plasma (oral group) and < 8.5 ng/swab in vaginal group were defined as "PK non-adherent." Logistic regression models were fit to calculate the combined predictive ability of the behavioural measures as summarized by area under the curve (AUC). Baseline characteristics associated with over-reporting daily product use relative to PK measures was assessed using a Generalized Linear Mixed Model.

RESULTS

In this random adherence cohort of VOICE participants assigned to active products, (N = 472), PK non-adherence was 69% in the oral group (N = 314) and 65% in the vaginal group (N = 158). Behaviourally, ≤ 10% of the cohort reported low/none use with any behavioural measure and accuracy was low (≤ 43%). None of the regression models had an AUC > 0.65 for any single or combined behavioural measures. Significant (p < 0.05) correlates of over-reporting included being very worried about getting HIV and being unmarried for the oral group; whereas for the vaginal group, being somewhat worried about HIV was associated with lower risk of over-reporting.

CONCLUSIONS

PK measures indicated similarly low adherence for the oral and vaginal groups. No behavioural measure accurately predicted PK non-adherence. Accurate real-time measures to monitor product adherence are urgently needed.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT00705679.

Population sexual behavior and HIV prevalence in Sub-Saharan Africa: missing links?

OBJECTIVES

Patterns of sexual partnering should shape HIV transmission in human populations. The objective of this study was to assess empirical associations between population casual sex behavior and HIV prevalence, and between different measures of casual sex behavior.

METHODS

An ecological study design was applied to nationally representative data, those of the Demographic and Health Surveys, in 25 countries of Sub-Saharan Africa. Spearman rank correlation was used to assess different correlations for males and females and their statistical significance.

RESULTS

Correlations between HIV prevalence and means and variances of the number of casual sex partners were positive, but small and statistically insignificant. The majority of correlations across means and variances of the number of casual sex partners were positive, large, and statistically significant. However, all correlations between the means, as well as variances, and the variance of unmarried females were weak and statistically insignificant.

CONCLUSIONS

Population sexual behavior was not predictive of HIV prevalence across these countries. Nevertheless, the strong correlations across means and variances of sexual behavior suggest that self-reported sexual data are self-consistent and convey valid information content. Unmarried female behavior seemed puzzling, but could be playing an influential role in HIV transmission patterns.

Sexual abstinence and other behaviours immediately following a new STI diagnosis among STI clinic patients: Findings from the Safe in the City trial

BACKGROUND

Few studies have assessed patients' sexual behaviours during the period immediately following a new diagnosis of a curable sexually transmitted infection (STI).

METHODS

Data were analysed from a behavioural study nested within the Safe in the City trial, which evaluated a video-based STI/HIV prevention intervention in three urban STI clinics. We studied 450 patients who reported having received a new STI diagnosis, or STI treatment, 3 months earlier. Participants reported on whether they seriously considered, attempted and succeeded in adopting seven sex-related behaviours in the interval following the diagnostic visit. We used multivariable logistic regression to identify, among men, correlates of two behaviours related to immediately reducing reinfection risk and preventing further STI transmission: sexual abstinence until participants were adequately treated and abstinence until their partners were tested for STIs.

RESULTS

Most participants reported successfully abstaining from sex until they were adequately treated for their baseline infection (89%-90%) and from sex with potentially exposed partners until their partners were tested for HIV and other STIs (66%-70%). Among men who intended to be abstinent until they were adequately treated, those who did not discuss the risks with a partner who was possibly exposed were more likely not to be abstinent (OR, 3.7; 95% CI 1.5 to 9.0) than those who had this discussion. Similarly, among men who intended to abstain from sex with any potentially exposed partner until the partner was tested for HIV and other STIs, those who reported not discussing the risks of infecting each other with HIV/STIs were more likely to be sexually active during this period (OR, 3.5; 95% CI 1.6 to 8.1) than were those who reported this communication.

CONCLUSIONS

Improved partner communication could facilitate an important role in the adoption of protective behaviours in the interval immediately after receiving a new STI diagnosis.

TRIAL REGISTRATION NUMBER

NCT00137670.

Social network recruitment for Yo Puedo: an innovative sexual health intervention in an underserved urban neighborhood—sample and design implications

Most existing evidence-based sexual health interventions focus on individual-level behavior, even though there is substantial evidence that highlights the influential role of social environments in shaping adolescents' behaviors and reproductive health outcomes. We developed Yo Puedo, a combined conditional cash transfer and life skills intervention for youth to promote educational attainment, job training, and reproductive health wellness that we then evaluated for feasibility among 162 youth aged 16-21 years in a predominantly Latino community in San Francisco, CA. The intervention targeted youth's social networks and involved recruitment and randomization of small social network clusters. In this paper we describe the design of the feasibility study and report participants' baseline characteristics. Furthermore, we examined the sample and design implications of recruiting social network clusters as the unit of randomization. Baseline data provide evidence that we successfully enrolled high risk youth using a social network recruitment approach in community and school-based settings. Nearly all participants (95%) were high risk for adverse educational and reproductive health outcomes based on multiple measures of low socioeconomic status (81%) and/or reported high risk behaviors (e.g., gang affiliation, past pregnancy, recent unprotected sex, frequent substance use; 62%). We achieved variability in the study sample through heterogeneity in recruitment of the index participants, whereas the individuals within the small social networks of close friends demonstrated substantial homogeneity across sociodemographic and risk profile characteristics. Social networks recruitment was feasible and yielded a sample of high risk youth willing to enroll in a randomized study to evaluate a novel sexual health intervention.