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

How Stigma Surrounding the Use of HIV Preexposure Prophylaxis Undermines Prevention and Pleasure: A Call to Destigmatize "Truvada Whores"

Antiretroviral preexposure prophylaxis (PrEP; emtricitabine and tenofovir disoproxil fumarate [Truvada]) prevents HIV without penalizing sexual pleasure, and may even enhance pleasure (e.g., by reducing HIV-related anxiety). However, concern about sexual risk behavior increasing with PrEP use (risk compensation) and corresponding stereotypes of promiscuity may undermine PrEP's preventive potential. In this commentary, we review literature on sexual behavior change accompanying PrEP use, discuss risk compensation concerns and the "Truvada whore" stereotype as PrEP barriers, question the appropriateness of restricting PrEP access because of risk compensation, and consider sexual pleasure as a benefit of PrEP, an acceptable motive for seeking PrEP, and a core element of health. It is essential for science to trump stereotypes and sex-negative messaging in guiding decision-making affecting PrEP access and uptake.

Y chromosome and HIV DNA detection in vaginal swabs as biomarkers of semen and HIV exposure in women

BACKGROUND

The inability to quantify sexual exposure to HIV limits the power of HIV prevention trials of vaccines, microbicides, and preexposure prophylaxis in women. We investigated the detection of HIV-1 and Y chromosomal (Yc) DNA in vaginal swabs from 83 participants in the HPTN 035 microbicide trial as biomarkers of HIV exposure and unprotected sexual activity.

METHODS

One hundred forty-three vaginal swabs from 85 women were evaluated for the presence of Yc DNA (Quantifiler Duo DNA quantification kit; Applied Biosystems) and total HIV-1 DNA (single-copy in-house quantitative polymerase chain reaction assay). Y DNA detection was paired with self-reported behavioral data with regard to recent coitus (≤1 week before collection) and condom usage (100% vs. <100% compliance).

RESULTS

Yc DNA was detected in 62 (43%) of 143 swabs. For the 126 visits at which both behavioral data and swabs were collected, Yc DNA was significantly more frequent in women reporting less than 100% condom usage (odds ratio, 10.69; 95% confidence interval, 2.27-50.32; P = 0.003). Notably, 27 (33%) of 83 swabs from women reporting 100% condom usage were positive for Yc DNA. HIV DNA was only detected in swabs collected postseroconversion.

CONCLUSIONS

The use of Yc DNA in HIV prevention trials could reliably identify subgroups of women who have unprotected sexual activity and could provide valuable exposure-based estimates of efficacy.

Traumatic stress and the mediating role of alcohol use on HIV-related sexual risk behavior: results from a longitudinal cohort of South African women who attend alcohol-serving venues

BACKGROUND

In South Africa, alcohol contributes to the HIV epidemic, in part, by influencing sexual behaviors. For some, high levels of alcohol consumption may be driven by previous traumatic experiences that result in traumatic stress. The purpose of this study was to quantify the longitudinal association between traumatic stress and unprotected sex among women who attend drinking venues and to assess whether this association was explained by mediation through alcohol use.

METHODS

Data were collected in 4 waves over a year from a prospective cohort of 560 women who regularly attended alcohol-serving venues in a Cape Town township. Longitudinal mixed models examined (1) the relationship between traumatic stress and counts of unprotected sex and (2) whether alcohol use mediated the association between traumatic stress and unprotected sex.

RESULTS

Most women reported elevated traumatic stress (80%) and hazardous alcohol use (88%) at least once during the study period. In models adjusted for covariates, traumatic stress was associated with unprotected sex (b = 0.28, SE = 0.06, t = 4.82, P < 0.001). In addition, traumatic stress was associated with alcohol use (b = 0.27, SE = 0.02, t = 14.25, P < 0.001) and was also associated with unprotected sex (b = 0.20, SE = 0.06, t = 3.27, P < 0.01) while controlling for alcohol use (b = 0.28, SE = 0.07, t = 4.25, P < 0.001). The test for the mediated effect established that alcohol use was a significant mediator, accounting for 27% of the total effect of traumatic stress on unprotected sex.

CONCLUSIONS

These results highlight the need to address traumatic stress among female venue patrons as an important precursor of HIV risk due to alcohol use.

Pregnancy prevention and condom use practices among HIV-infected women on antiretroviral therapy seeking family planning in Lilongwe, Malawi

Background

Programs for integration of family planning into HIV care must recognize current practices and desires among clients to appropriately target and tailor interventions. We sought to evaluate fertility intentions, unintended pregnancy, contraceptive and condom use among a cohort of HIV-infected women seeking family planning services within an antiretroviral therapy (ART) clinic.

Methods

200 women completed an interviewer-administered questionnaire during enrollment into a prospective contraceptive study at the Lighthouse Clinic, an HIV/ART clinic in Lilongwe, Malawi, between August and December 2010.

Results

Most women (95%) did not desire future pregnancy. Prior reported unintended pregnancy rates were high (69% unplanned and 61% unhappy with timing of last pregnancy). Condom use was inconsistent, even among couples with discordant HIV status, with lack of use often attributed to partner’s refusal. Higher education, older age, lower parity and having an HIV negative partner were factors associated with consistent condom usage.

Discussion

High rates of unintended pregnancy among these women underscore the need for integ rating family planning, sexually transmitted infection (STI) prevention, and HIV services. Contraceptive access and use, including condoms, must be improved with specific efforts to enlist partner support. Messages regarding the importance of condom usage in conjunction with more effective modern contraceptive methods for both infection and pregnancy prevention must continue to be reinforced over the course of ongoing ART treatment.

Dynamics of non-cohabiting sex partnering in sub-Saharan Africa: a modelling study with implications for HIV transmission

Objective

To develop an analytical understanding of non-cohabiting sex partnering in sub-Saharan Africa (SSA) using nationally representative sexual behaviour data.

Method

A non-homogenous Poisson stochastic process model was used to describe the dynamics of non-cohabiting sex. The model was applied to 25 countries in SSA and was fitted to Demographic and Health Survey data. The country-specific mean values and variances of the distributions of number of non-cohabiting partners were estimated.

Results

The model yielded overall robust fits to the empirical distributions stratified by marital status and sex. The median across all country-specific mean values was highest for unmarried men at 0.574 non-cohabiting partners over the last 12 months, followed by that of unmarried women at 0.337, married men at 0.192 and married women at 0.038. The median of variances was highest for unmarried men at 0.127, followed by married men at 0.057, unmarried women at 0.003 and married women at 0.000. The largest variability in mean values across countries was for unmarried men (0.103–1.206), and the largest variability in variances was among unmarried women (0.000–1.994).

Conclusions

Non-cohabiting sex appears to be a random ‘opportunistic’ phenomenon linked to situations that may facilitate it. The mean values and variances of number of partners in SSA show wide variation by country, marital status and sex. Unmarried individuals have larger mean values than their married counterparts, and men have larger mean values than women. Unmarried individuals appear to play a disproportionate role in driving heterogeneity in sexual networks and possibly epidemiology of sexually transmitted infections.

Peer Influences on Sexual Activity among Adolescents in Ghana

Little is known about the influences of peers on the sexual activity of adolescents in sub-Saharan Africa. Better understanding of these issues could lead to more effective sexual and reproductive health interventions. Using two waves of survey data from 1,275 adolescents in two southeastern Ghanaian towns, we examine age, sex, and community differences in peer group characteristics. We also examine prospective associations between peer group characteristics and self-reported sexual initiation and multiple partnerships during a 20-month follow-up period. Sex differences in peer-context variables were small. Affiliation with antisocial peers and perceived peer norms favoring sex increased the odds of transition to first sex. Having more friends increased the odds among younger respondents of acquiring multiple new sexual partners. Among males, perceived peer norms favoring sex increased the odds of acquiring multiple partners. We discuss the implications of these findings for adolescent sexual and reproductive health intervention strategies in sub-Saharan Africa, and conclude that peer-based interventions may be best suited to the needs of at-risk adolescent boys.

Population-level impact of Zimbabwe's National Behavioural Change Programme

OBJECTIVE

To assess the impact of Zimbabwe's National Behavioural Change Programme (NBCP) on biological and behavioral outcomes.

METHODS

Representative household biobehavioral surveys of 18- to 44-year-olds were conducted in randomly selected enumeration areas in 2007 and 2011 to 2012. We examined program impact on HIV prevalence among young women, nonregular partnerships, condom use with nonregular partners, and HIV testing, distinguishing between highly exposed and low-exposed communities and individuals. We conducted (1) difference-in-differences analyses with communities as unit of analysis and (2) analyses of key outcomes by individual-level program exposure.

RESULTS

Four thousand seven hundred seventy-six people were recruited in 2007 and 10,059 in 2011 to 2012. We found high exposure to NBCP in 2011. Prevalence of HIV and reported risky behaviors declined between 2007 and 2011. Community-level analyses showed a smaller decline in HIV prevalence among young women in highly exposed areas (11.0%-10.1%) than low-exposed areas (16.9%-10.3%, P = 0.078). Among young men, uptake of nonregular partners declined more in highly exposed areas (25%-16.8%) than low-exposed areas (21.9%-20.7%, P = 0.055) and HIV testing increased (27.2%-46.1% vs. 31.0%-34.4%, P = 0.004). Individual-level analyses showed higher reported condom use with nonregular partners among highly exposed young women (53% vs. 21% of unexposed counterparts, P = 0.037).

CONCLUSIONS

We conducted the first impact evaluation of a NBCP and found positive effects of program exposure on key behaviors among certain gender and age groups. HIV prevalence among young women declined but could not be attributed to program exposure. These findings suggest substantial program effects regarding demand creation and justify program expansion.

Age at first intercourse and subsequent sexual partnering among adult women in the United States, a cross-sectional study

BACKGROUND

Concurrency and serial monogamy may increase risk for STIs when gaps fall within the infectious period. This study examined the association between early sexual debut and concurrent or serial sexual partnering among heterosexual adult women.

METHODS

We identified 6,791 heterosexually active women, ages 21-44, from the 2006-2010 National Survey of Family Growth, a multi-stage probability sample of women in the United States. Self-reported age at first intercourse was categorized as <15, 15-17 and ≥18 years (referent). Sexual partnering was defined as concurrency (within the same month), serial monogamy with either a 1-3 month, or ≥4 month gap between partners, or monogamy (referent) in the year prior to interview. Polytomous logistic models provided adjusted odds ratios (aOR) and 95% confidence intervals (CI).

RESULTS

Concurrent partnerships in the year prior to interview were reported by 5.2% of women. Serial monogamy with a 1-3 month gap was reported by 2.5% of women. Compared with women whose sexual debut was ≥18 years, those <15 years at sexual initiation had 3.7 times the odds of reporting concurrent partnerships (aOR: 3.72; 95% CI: 2.46-5.62). Women <15 years of age at sexual debut had twice the odds of serial monogamy with gap lengths of 1-3 months between partners (aOR1-3 months: 2.13; 95% CI 1.15-3.94) as compared to women ≥18 years at sexual debut.

CONCLUSIONS

Sexual debut at <15 years is associated with both concurrency and serial monogamy with 1-3 month gaps between partners in U.S. women aged 21-44.

Systematic assessment of condom use measurement in evaluation of HIV prevention interventions: need for standardization of measures

When evaluating HIV prevention interventions, condom use is a common outcome measure used to assess changes in HIV-related behaviors; however, no widely accepted standards exist for its measurement. Using systematic review data on HIV prevention interventions conducted in low- and middle-income countries, we examined trends in condom use measurement since 1990. We abstracted data from standardized forms on six dimensions of condom use: partner type, temporal period, measurement scale, consistency, controlling for abstinence, and type of sex. Of 215 studies reviewed, 109 studies (51 %) measured condom use as a primary outcome. Outcomes were stratified by partner type in 47 studies (43 %). Assessing condom use at last sex was the most common measurement. Consistency of condom use was assessed in 47 studies (43 %). Developing and utilizing standards for condom use measurement would increase comparability of findings across studies and benefit HIV prevention research. Recommendations include measuring condom use at last sex, frequency of condom use, and number of protected sex acts in studies evaluating the efficacy of behavioral interventions on sexual risk behavior.

Are hormonal contraceptive users more likely to misreport unprotected sex? Evidence from a biomarker validation study in Zimbabwe

We analyzed biomarker validation data of unprotected sex from women in Zimbabwe to determine whether condom and sexual behavior misreporting differs between users of different contraceptive methods. Self-reported sexual behavior was compared with the presence of prostate-specific antigen (PSA) in vaginal fluid, a biomarker of semen exposure. Of the 195 women who were PSA positive, 94 (48 %) reported no sex or only condom-protected sex. Hormonal contraceptive users misreported sexual behavior less than women using non-hormonal methods (45 vs. 67 %, P = 0.03). This misclassification pattern could have implications on the elevated risk of HIV infection associated with hormonal contraception in some studies.

Changes in sexual risk behavior in the Mombasa cohort: 1993-2007

The Mombasa Cohort is an open cohort study following HIV-seronegative women reporting transactional sex. Established in 1993, the cohort provides regular HIV counseling and testing at monthly visits. Over time, HIV acquisition risk has declined steadily in this cohort. To evaluate whether this decline may reflect changes in sexual risk behavior, we investigated trends in condom use and partner numbers among women who participated in the Mombasa Cohort between 1993 and 2007. Multinomial logistic regression and generalized estimating equations were used to evaluate the association of calendar time and follow-up time with key risk behaviors, after adjustment for potential confounding factors. At enrollment visits by 1,844 women, the adjusted probability of never using condoms decreased over time, from 34.2% to 18.9%. Over 23,911 follow-up visits, the adjusted probabilities of reporting >2 partners decreased from 9.9% to 4.9% and inconsistent condom use decreased from 7.9% to 5.3% after ≥12 cohort visits. Important predictors of risk behavior were work venue, charging low fees for sex, and substance abuse. Women with a later sexual debut had less risky behavior. Although sexual risk has declined among women participating in the Mombasa Cohort, HIV acquisition continues to occur and interventions to promote and reinforce safer sex are clearly needed.

Discordance of HIV and HSV-2 biomarkers and self-reported sexual behaviour among orphan adolescents in Western Kenya

BACKGROUND

This paper examines the discordance between biological data of HIV and herpes simplex virus type 2 (HSV-2) infections and self-reported questionnaire responses among orphan adolescents in Western Kenya.

METHODS

In 2011, 837 orphan adolescents from 26 primary schools were enrolled in an HIV prevention trial. At baseline, blood samples were drawn for HIV and HSV-2 infection biomarker testing, and participants completed an audio computer-assisted self-interviewing survey.

RESULTS

Comparing biological data with self-reported responses indicated that 70% of HIV-positive (7 out of 10) and 64% of HSV-2-positive (18 out of 28 positive) participants reported never having had sex. Among ever-married adolescents, 65% (57 out of 88) reported never having had sex. Overall, 10% of study participants appeared to have inconsistently reported their sexual behaviour. Logistic regression analyses indicated that lower educational level and exam scores were significant predictors of inconsistent reporting.

CONCLUSIONS

Our study demonstrates the discordance between infections measured by biomarkers and self-reports of having had sex among orphan adolescents in Kenya. In order to detect programme effects accurately in prevention research, it is necessary to collect both baseline and endline biological data. Furthermore, it is recommended to triangulate multiple data sources about adolescent participants' self-reported information about marriage and pregnancies from school records and parent/guardians to verify the information. Researchers should recognise potential threats to validity in data and design surveys to consider cognitive factors and/or cultural context to obtain more accurate and reliable information from adolescents regarding HIV/sexually transmitted infection risk behaviours.

CLINICAL TRAIL REGISTRATION NUMBER

NCT01501864.

The use of biomarkers of semen exposure in sexual and reproductive health studies

Biomarkers of semen exposure have been used in studies investigating the safety and efficacy of barrier methods of contraception. They have been used as objective indicators of semen exposure when studying sexual behaviors and in human immunodeficiency virus/sexually transmitted infection research interventions where participants are advised to avoid unprotected sex. Semen biomarkers have also been used to assess or validate self-reported sexual behaviors or condom use in reproductive health settings. Prostate-specific antigen (PSA) and Y chromosome DNA (Yc-DNA) have each been evaluated in the past as semen biomarkers and are the most widely used in the field. While both are considered reliable for evaluating exposure to semen, each has unique characteristics. In this report, we summarize the literature and provide some considerations for reproductive health researchers who are interested in using PSA or Yc-DNA as semen biomarkers. We also synthesize our previous published work on the optimal conditions of collecting and storing specimens and assay performance in the presence of other vaginal products that may influence various assays. Semen biomarkers are innovative and promising tools to further study and better understand women's reproductive and sexual health and behavior. More research is needed to better understand the strengths, limitations, and optimal performance conditions of specific assays in vivo.

Validity of behavioral measures as proxies for HIV-related outcomes

Over the last 30 years, expectations for the quality, validity, and objectivity of the outcome measures used to assess the impact of behavior change interventions related to HIV have steadily increased. At this point (mid-2014 at this writing), biologic evidence or biomarkers of the incidence of HIV and other sexually transmitted infections in a target population is clearly preferable to self-reports of behavior. This kind of evidence is, however, much more expensive to collect than participants' reports of behavior change (eg, increased condom use, reduced substance use or abstinence from substance use, and high levels of medication adherence). In addition, although potentially less subject to reporting bias, biomarkers and biologic outcomes have their own flaws. In this article, we review the literature on the validity of self-reports of outcomes most relevant to HIV behavior change interventions, sexual behavior (ever having had sex and condom use), substance use, and medication adherence. We note the extent to which they may be adequate outcome measures without biologic data, and the conditions under which they may be most likely to be sufficient. We also argue, like many others, that where possible, both self-report and biologic measures should be collected.

The heterogeneous effects of HIV testing

An extensive multi-disciplinary literature examines the effects of learning one's HIV status on subsequent risky sexual behaviors. However, many of these studies rely on non-experimental designs; use self-reported outcome measures; or both. In this study, we investigate the effects of a randomly assigned home based HIV testing and counseling (HTC) intervention on risky sexual behaviors and schooling investments among school-age females in Malawi. We find no overall effects on HIV, Herpes Simplex Virus (HSV-2), or achievement test scores at follow-up. However, among the small group of individuals who tested positive for HIV, we find a large increase in the probability of HSV-2 infection, with this effect being stronger among those surprised by their test results. Similarly, those surprised by HIV-negative test results have significantly higher achievement test scores at follow-up, consistent with increased returns to investments in human capital.

Challenges in measuring the sequencing of life events among adolescents in Malawi: a cautionary note

Using data from two rounds of the Malawi Schooling and Adolescent Survey, this research note examines consistency of retrospective reporting on the timing and sequencing of sexual initiation, school leaving, and marriage. The analysis, which compares reporting of events both within and between rounds, indicates substantial inconsistency in reporting of event sequences and highlights difficulties in measuring transitions to adulthood in sub-Saharan Africa with survey data.

A digital network approach to infer sex behavior in emerging HIV epidemics

Purpose

Improve the ability to infer sex behaviors more accurately using network data.

Methods

A hybrid network analytic approach was utilized to integrate: (1) the plurality of reports from others tied to individual(s) of interest; and (2) structural features of the network generated from those ties. Network data was generated from digitally extracted cell-phone contact lists of a purposeful sample of 241 high-risk men in India. These data were integrated with interview responses to describe the corresponding individuals in the contact lists and the ties between them. HIV serostatus was collected for each respondent and served as an internal validation of the model’s predictions of sex behavior.

Results

We found that network-based model predictions of sex behavior and self-reported sex behavior had limited correlation (54% agreement). Additionally, when respondent sex behaviors were re-classified to network model predictions from self-reported data, there was a 30.7% decrease in HIV seroprevalence among groups of men with lower risk behavior, which is consistent with HIV transmission biology.

Conclusion

Combining the relative completeness and objectivity of digital network data with the substantive details of classical interview and HIV biomarker data permitted new analyses and insights into the accuracy of self-reported sex behavior.

Veracity and rhetoric in paediatric medicine: a critique of Svoboda and Van Howe's response to the AAP policy on infant male circumcision

In a recent issue of the Journal of Medical Ethics,Svoboda and Van Howe commented on the 2012 changein the American Academy of Pediatrics (AAP) policy on newborn male circumcision, in which the AAP stated that benefits of the procedure outweigh the risks. Svoboda and Van Howe disagree with the AAP conclusions. We show here that their arguments against male circumcision are based on a poor understanding of epidemiology,erroneous interpretation of the evidence, selective citation of the literature, statistical manipulation of data, and circular reasoning. In reality, the scientific evidence indicates that male circumcision, especially when performed in the newborn period, is an ethically and medically sound low-risk preventive health procedure conferring a lifetime of benefits to health and well-being.Policies in support of parent-approved elective newborn circumcision should be embraced by the medical,scientific and wider communities.

Prevalence of human papillomavirus in adolescent girls before reported sexual debut

Background. Human papillomavirus (HPV) vaccines are recommended for girls prior to sexual debut because they are most effective if administered before girls acquire HPV. Little research has been done on HPV prevalence in girls who report not having passed sexual debut in high HPV-prevalence countries.

Methods. Using attendance registers of randomly selected primary schools in the Mwanza region of Tanzania, we enrolled girls aged 15–16 years who reported not having passed sexual debut. A face-to-face interview on sexual behavior and intravaginal practices, and a nurse-assisted self-administered vaginal swab were performed. Swabs were tested for 13 high-risk and 24 low-risk HPV genotypes.

Results. HPV was detected in 40/474 (8.4%; 95% confidence interval [CI], 5.9–11.0) girls. Ten different high-risk and 21 different low-risk genotypes were detected. High-risk genotypes were detected in 5.3% (95% CI, 3.5–7.8). In multivariable analysis, only intravaginal cleansing (practiced by 20.9%) was associated with HPV detection (adjusted odds ratio = 2.19, 95% CI, 1.09–4.39).

Conclusion. This cohort of adolescent Tanzanian girls had a high HPV prevalence prior to self-reported sexual debut, and this was associated with intravaginal cleansing. This most likely reflects underreporting of sexual activity, and it is possible that intravaginal cleansing is a marker for unreported sexual debut or nonpenetrative sexual behaviors.

Does tenofovir gel or do other microbicide products affect detection of biomarkers of semen exposure in vitro?

OBJECTIVES

There is currently no information on whether products evaluated in HIV microbicide trials affect the detection of the semen biomarkers prostate-specific antigen (PSA) or Y chromosome DNA.

STUDY DESIGN

We tested (in vitro) dilutions of tenofovir (TFV), UC781 and the hydroxyethylcellulose (HEC) placebo gels using the Abacus ABAcard and the quantitative (Abbott Architect total PSA) assays for PSA and Y chromosome DNA by real-time polymerase chain reaction.

RESULTS

TFV gel and the HEC placebo adversely affected PSA detection using the ABAcard but not the Abbott Architect total PSA assay. UC781 adversely affected both the ABAcard and Abbott Architect total PSA assays. While there were some quantitative changes in the magnitude of the signal, none of the products affected positivity of the Y chromosome assay.

CONCLUSIONS

The presence of TFV or HEC gels did not affect quantitative PSA or Y chromosome detection in vitro. Confirmation of these findings is recommended using specimens obtained following use of these gels in vivo.

IMPLICATIONS

Researchers should consider the potential for specific microbicides or any products to affect the particular assay used for semen biomarker detection. The ABAcard assay for PSA detection should not be used with TFV UC781, or HEC.

Using biomarkers to assess the validity of sexual behavior reporting across interview modes among young women in Kampala, Uganda

Understanding the transmission dynamics of HIV and other sexually transmitted infections is critically dependent on accurate behavioral data. This study investigates the effect of the mode of questionnaire delivery on the quality of sexual behavior reporting in a 2010 survey conducted in Kampala, Uganda, among 18-24-year-old women. We compare the reported prevalence of five sexual outcomes across three interview modes: traditional face-to-face interviewing (FTFI) in which question rewording was permitted, FTFI administered via computer-assisted personal interviewing (CAPI) in which questions were read as written, and audio computer-assisted self-interviewing (ACASI) in which participants listened to prerecorded questions and entered responses using a computer touchscreen. We then assess the validity of the data by evaluating the reporting of sexual experience against three biological markers. Results suggest that ACASI elicits higher reporting of some key indicators than FTFI does, but self-reports from all interview modes were subject to validity concerns when compared with biomarker data. The study highlights the important role that biomarkers can play in sexual behavior research.

Biomarker validation of recent unprotected sexual intercourse in a prospective study of young women engaged in sex work in Phnom Penh, Cambodia

BACKGROUND

Accurate measurement of unprotected sex is essential in HIV prevention research. Since 2001, the 100% Condom Use Program targeting female sex workers (FSWs) has been a central element of the Cambodian National HIV/AIDS Strategy. We sought to assess the validity of self-reported condom use using the rapid prostate-specific antigen (PSA) test among Cambodian FSWs.

METHODS

From 2009 to 2010, we enrolled 183 FSWs in Phnom Penh in a prospective study of HIV risk behavior. Prostate-specific antigen test results from the OneStep ABAcard were compared with self-reported condom use in the past 48 hours at quarterly follow-up visits.

RESULTS

Among women positive for seminal fluid at the first follow-up visit, 42% reported only protected sex or no sex in the detection period. Discordant results were more likely among brothel and street-based FSW versus entertainment (56% vs. 17%), recent (last 3 months) amphetamine-type stimulant (ATS) users (53% vs. 20%), and those with 5 or more partners in the past month (58% vs. 13%). In multivariable regression models, positive PSA results were associated with recent ATS use (adjusted risk ratio [ARR], 1.5; 95% confidence interval [CI], 1.1-2.2), having a nonpaying last sex partner (ARR, 1.7; CI, 1.2-2.5), and sex work venue (ARR, 3.0; CI, 1.4-6.5). Correspondingly, women with a nonpaying last sex partner were more likely to report unprotected sex (ARR, 1.5; CI, 1.1-2.2), but no associations were found with sex work venue or ATS use.

CONCLUSIONS

Results confirm the questionable validity of self-reported condom use among FSW. The PSA biomarker assay is an important monitoring tool in HIV/sexually transmitted infection research including prevention trials.

Biological markers of sexual activity: tools for improving measurement in HIV/sexually transmitted infection prevention research

Research on interventions to prevent HIV and other sexually transmitted infections (STIs) is heavily influenced by participant reporting of sexual behavior, despite uncertainty about its validity. Exclusive reliance on participant self-report often is based, overtly or by implication, on 4 assumptions: (1) no feasible alternatives exist; (2) misreporting can be minimized to levels that can be disregarded; (3) misreporting tends to underreport sensitive behaviors; and (4) misreporting tends to be nondifferential with respect to the groups being compared. The objective of this review are to evaluate these assumptions, including a review of studies using semen biomarkers to evaluate the validity of self-reported data, and to make recommendations for applying biological markers of semen exposure detectable in women to further strengthen research on HIV/STI prevention. Increasing evidence shows that semen biomarkers provide an important means of assessing and augmenting the validity of studies on HIV/STI prevention. Additional biomarkers are needed to assess male exposure to vaginal sex and both male and female exposure to anal sex. Methods and study designs that incorporate biomarkers into studies collecting self-reported behavioral data should be considered where possible.

Comparisons of reported sexual behaviors from a retrospective survey versus a prospective diary in the Botswana Defence Force

This study compares self-reported sexual behaviors from a retrospective survey and a prospective diary among Botswana Defence Force (BDF) personnel. One hundred sixty-one male participants, aged 18-30, completed two weekly prospective diaries and a retrospective survey querying them about behaviors reported during the same time frame as the diaries. Most reported behaviors were similar between the two data collection methods. However, there was low agreement for reporting sex with a spouse and exchanging material goods for sex with a casual partner; frequency of sex and condom use rates (CURs) among married participants also differed. When comparing survey condom use frequencies to diary CURs, the level of agreement diminished from the always to occasionally condom use categories. Inconsistencies in reporting may be due to the frequency of the sexual behavior, question sensitivity, the data collection setting, and the interpretation of response categories. Further research is needed to improve accurate reporting of sexual behaviors.

Social desirability bias in sexual behavior reporting: evidence from an interview mode experiment in rural Malawi

CONTEXT

Social desirability bias is problematic in studies that rely on self-reported sexual behavior data. Where gender norms create different expectations about socially acceptable behavior, males and females face distinct pressures in reporting certain outcomes, which can distort assessments of risk for HIV and STIs.

METHODS

In 2009, relationship and sexual behavior data were collected from 1,750 never-married males and females aged 16-18 via audio computer-assisted self-interviewing (audio-CASI) during the third round of the Malawi Schooling and Adolescent Study. A comparison group of 311 youth completed an identical questionnaire in face-to-face interviews. To assess whether interview mode may have influenced participants' reporting of sensitive behavior, reports of sexual experience in the two groups were compared. Multiple logistic regression analysis was used to identify associations between interview mode and reports of these behaviors, by gender.

RESULTS

In adjusted regression models, males were less likely to report ever having had a girlfriend in audio-CASI than in face-to-face interviews (odds ratio, 0.4), but they were more likely to report having had sex with a relative or teacher (3.5). For females, reports of ever having had a boyfriend or having had sex did not differ between modes. A small proportion of females reported ever having had sex with a relative or teacher in audio-CASI, while none did so in face-to-face interviews.

CONCLUSIONS

The method used for collecting relationship and sexual behavior data may influence the reported prevalence of some key behaviors, particularly among males. Further research is needed to improve methods of collecting sensitive data.

Hormonal contraception and HIV: the methods have confused the message

OBJECTIVE

To examine different scenarios through which confounding by condom use may lead to inaccurate conclusions about the effect of hormonal contraception on HIV acquisition in women.

DESIGN AND METHODS

Scenario analyses were conducted to evaluate the impact of coarse adjustment for condom use and condom misreporting on adjusted relative risk estimates for HIV acquisition in injectable hormonal contraception (IHC) users vs. nonusers.

RESULTS

Analyses crudely accounting for condom use through a binary variable result in biased hormonal contraception-related risk estimates if condoms are used during follow-up periods in which any unprotected sex is reported and condom use differs by hormonal contraception use. We found that over-reporting of condom use is plausible in at least one recent study, as demonstrated by high pregnancy rates given, reported IHC and condom use. Over-reporting of condom use also biases estimates, typically leading to underestimation of IHC-related risk if over-reporting is the same among IHC and non-hormonal contraception users, and overestimation of IHC-related risk if condom misreporting is differential by IHC use. The impact of misreported condom use is most pronounced in study populations with high condom uptake.

CONCLUSIONS

Discrepant findings in hormonal contraception-HIV-related research may result from inadequate measurement or adjustment for confounding by condom use. Future studies should precisely account for condom use in statistical analyses. Studies should aim to quantify the degree of condom use misreporting, by comparing reported condom use to pregnancy, HIV or other sexually transmitted infection rates, and if possible, testing stored genital swabs for prostate-specific antigen or Y chromosome.

Increasing adolescent HIV prevalence in Eastern Zimbabwe--evidence of long-term survivors of mother-to-child transmission?

Recent data from the Manicaland HIV/STD Prevention Project, a general-population open HIV cohort study, suggested that between 2004 and 2007 HIV prevalence amongst males aged 15–17 years in eastern Zimbabwe increased from 1.20% to 2.23%, and in females remained unchanged at 2.23% to 2.39%, while prevalence continued to decline in the rest of the adult population. We assess whether the more likely source of the increase in adolescent HIV prevalence is recent sexual HIV acquisition, or the aging of long-term survivors of perinatal HIV acquisition that occurred during the early growth of the epidemic. Using data collected between August 2006 and November 2008, we investigated associations between adolescent HIV and (1) maternal orphanhood and maternal HIV status, (2) reported sexual behaviour, and (3) reporting recurring sickness or chronic illness, suggesting infected adolescents might be in a late stage of HIV infection. HIV-infected adolescent males were more likely to be maternal orphans (RR = 2.97, p<0.001) and both HIV-infected adolescent males and females were more likely to be maternal orphans or have an HIV-infected mother (male RR = 1.83, p<0.001; female RR = 16.6, p<0.001). None of 22 HIV-infected adolescent males and only three of 23 HIV-infected females reported ever having had sex. HIV-infected adolescents were 60% more likely to report illness than HIV-infected young adults. Taken together, all three hypotheses suggest that recent increases in adolescent HIV prevalence in eastern Zimbabwe are more likely attributable to long-term survival of mother-to-child transmission rather than increases in risky sexual behaviour. HIV prevalence in adolescents and young adults cannot be used as a surrogate for recent HIV incidence, and health systems should prepare for increasing numbers of long-term infected adolescents.

Demographic and health surveys indicate limited impact of condoms and HIV testing in four African countries

Condom promotion and HIV testing for the general population have been major components of HIV prevention efforts in sub-Saharan Africa's high prevalence HIV epidemics, although little evidence documents their public health impact. Recent enhancements to the large, population-based demographic and health surveys (DHS) and AIDS information surveys (AIS) allow use of these data to assess the population-wide impact of these strategies. We analysed the latest DHS and AIS data from four sub-Saharan African countries with high prevalence, heterosexually transmitted HIV epidemics (Côte d'Ivoire, Swaziland, Tanzania and Zambia; N = 48 298) to answer two questions: 1) Are men and women who use condoms less likely to be HIV-infected than those who do not?; and 2) Are men and women who report knowing their HIV status more likely to use condoms than those who do not? Consistent condom use was associated with lower HIV infection rates for Swazi men but with higher HIV infection rates for women in Tanzania and Zambia; it made no significant difference in the other five sex/country subgroups analysed. Inconsistent condom use was not significantly associated with HIV status in any subgroup. Knowing one's HIV status was consistently associated with higher rates of condom use only among married people who were HIV-positive, even though condom use in this group remained relatively low. Effects of knowing one's HIV status among other subgroups varied. These results suggest that condoms have had little population-wide impact for HIV/AIDS prevention in these four countries. HIV testing appears to be associated with increased condom use mainly among people in stable partnerships who test positive. HIV testing and condom promotion may be more effective when targeted to specific groups where there is evidence of benefit rather than to general populations.

Use of hormonal contraceptives and HIV acquisition in women: a systematic review of the epidemiological evidence

Whether or not the use of hormonal contraception affects risk of HIV acquisition is an important question for public health. We did a systematic review, searching PubMed and Embase, aiming to explore the possibility of an association between various forms of hormonal contraception and risk of HIV acquisition. We identified 20 relevant prospective studies, eight of which met our minimum quality criteria. Of these eight, all reported findings for progestin-only injectables, and seven also reported findings for oral contraceptive pills. Most of the studies that assessed the use of oral contraceptive pills showed no significant association with HIV acquisition. None of the three studies that assessed the use of injectable norethisterone enanthate showed a significant association with HIV acquisition. Studies that assessed the use of depot-medroxyprogesterone acetate (DMPA) or non-specified injectable contraceptives had heterogeneous methods and mixed results, with some investigators noting a 1·5-2·2 times increased risk of HIV acquisition, and others reporting no association. Thus, some, but not all, observational data raise concern about a potential association between use of DMPA and risk of HIV acquisition. More definitive evidence for the existence and size of any potential effect could inform appropriate counselling and policy responses in countries with varied profiles of HIV risk, maternal mortality, and access to contraceptive services.

Biomarker evaluation of self-reported condom use among women in HIV-discordant couples

Self-reported condom use is a commonly collected statistic, yet its use in research studies may be inaccurate. We evaluated this statistic among women in HIV-discordant couples enrolled in a clinical trial in Nairobi, Kenya. Vaginal swabs were acquired from 125 women and tested for prostate-specific antigen (PSA), a biomarker for semen exposure, using an enzyme-linked immunosorbent assay. Ten (10%) of 98 women who reported 100% use of condoms in the previous month tested PSA positive. In a bivariate logistic regression analysis, among women who reported 100% condom use in the previous month, those with ≤8 years of school had significantly higher odds of testing PSA-positive (odds ratio [OR] = 8.39, 95% confidence interval [CI] 1.02-69.13) than women with more schooling. Our estimate may be conservative, as the ability to detect PSA may be limited to 24-48 hours after exposure. Less educated women may be a target group for counselling regarding reporting sexual behaviour in clinical trials.

Comparison of adolescents' reports of sexual behavior on a survey and sexual health history calendar

Assessing sexual risk is critical for human immunodeficiency virus (HIV) and sexually transmitted infection (STI) prevention with adolescents. This article compares sexual risk reports from two self-administered instruments, a standard survey and a sexual health history calendar (SHHC), among racially diverse youth (n = 232) ages 14 to 21 seeking services at a public health clinic. Agreement between methods was assessed using Lin's concordance correlation coefficients (CCC) and Bland-Altman plots. Lin's CCC showed poor to moderate agreement between instruments on reports of sexual partners in the past 3 (0.47), 6 (0.55), and 12 (0.49) months. While individual sexual partner questions were refused a total of 179 times on the survey, youth reported having sexual partners during the same time period on the SHHC in most (77.1%) of these instances. Poor agreement was also found for condom use frequency (CCC = 0.17), with youth's frequency of condom use on the SHHC differing from that reported on the survey for more than half (55.6%) of the months they were sexually active. While lack of objective sexual behavior measures limits conclusions about the accuracy of reports, the ways in which youth's responses varied across instruments may offer insight into the complexity of adolescent sexual risk taking as well as have important implications for development of HIV/STI preventive interventions.

An evaluation of methods to improve the reporting of adherence in a placebo gel trial in Andhra Pradesh, India

Female sex workers (FSWs) were recruited for a 4-month placebo vaginal gel trial in Nellore, India. Two experiments explored if prior knowledge of biomarkers for unprotected sex and insertion of gel applicators would yield more accurate self-reports. A third experiment compared self-reports of gel use and adherence levels between FSWs randomly assigned to interactive voice response survey (IVRS) and those assigned to paper diaries. Prior knowledge of biomarkers did not improve accuracy of self-reported condom or gel use, nor did it affect actual adherence. Of those who tested positive for the presence of semenogelin in the vagina, 76% reported no unprotected sex in the previous 48 h. Overall, women reported using gel on 90% of days whereas the biomarker indicated gel use on fewer than 50% of days. Compliance to IVRS was low, despite familiarity with mobile phone technology. Additional explorations with other populations are needed.

Menstruation and School Absenteeism: Evidence from Rural Malawi

The provision of toilets and menstrual supplies has emerged as a promising programmatic strategy to support adolescent girls' school attendance and performance in less developed countries. We use the first round of the Malawi Schooling and Adolescent Survey (MSAS) to examine the individual- and school-level factors associated with menstruation-related school absenteeism. The MSAS is a school-based longitudinal survey of adolescent students enrolled in coed public primary schools in the southern districts of Machinga and Balaka who were aged 14-16 in 2007. Although one-third of female students report missing at least one day of school at their last menstrual period, our data suggest that menstruation only accounts for a small proportion of all female absenteeism and does not create a gender gap in absenteeism. We find no evidence for school-level variance in menstruation-related absenteeism, suggesting that absenteeism is not sensitive to school environments. Rather, co-residence with a grandmother and spending time on school work at home reduce the odds of absence during the last menstrual period.

Loss to follow-up as a competing risk in an observational study of HIV-1 incidence

OBJECTIVE

Conventional survival estimates may be biased if loss to follow-up (LTF) is associated with the outcome of interest. Our goal was to assess whether the association between sexual risk behavior and HIV-1 acquisition changed after accounting for LTF with competing risks regression.

METHODS

HIV-1-seronegative women who enrolled in a Kenyan sex worker cohort from 1993-2007 were followed prospectively and tested for HIV at monthly clinic visits. Our primary predictor was self-reported sexual risk behavior in the past week, analyzed as a time-dependent covariate. Outcomes included HIV-1 acquisition and LTF. We analyzed the data using Cox proportional hazards regression and competing risks regression, in which LTF was treated as a competing event.

RESULTS

A total of 1,513 women contributed 4,150 person-years (py), during which 198 (13.1%) acquired HIV-1 infection (incidence, 4.5 per 100 py) and 969 (64.0%) were LTF (incidence, 23.4 per 100 py). After adjusting for potential confounders, women reporting unprotected sex with multiple partners were less likely to be lost to follow-up (adjusted sub-hazard ratio (aSHR) 0.50, 95% confidence interval (CI) 0.32-0.76, relative to no sexual activity). The risk of HIV-1 acquisition after reporting unprotected sex with multiple partners was similar with Cox regression (adjusted hazard ratio (aHR) 2.41, 95% CI 1.36-4.27) and competing risks regression (aSHR 2.47, 95% CI 1.33-4.58).

CONCLUSIONS

Unprotected sex with multiple partners was associated with higher HIV-1 acquisition risk, but lower attrition. This differential attrition did not substantially bias Cox regression estimates when compared to competing risks regression results.

Hormonal contraceptive use and female-to-male HIV transmission: a systematic review of the epidemiologic evidence

OBJECTIVE

To systematically review epidemiologic evidence assessing whether hormonal contraception alters the risk of HIV transmission from an HIV-positive woman to an HIV-negative male partner.

DESIGN

Systematic review.

METHODS

We included articles published or in press through December 15, 2011. We assessed studies with direct evidence on hormonal contraception use and HIV transmission, and summarized studies with indirect evidence related to genital or plasma viral load.

RESULTS

: One study provided direct evidence on oral contraceptive pills (OCPs) or injectable contraception and female-to-male HIV transmission; both injectables [Cox-adjusted hazard ratio (adjHR) 1.95, 95% confidence interval (CI) 1.06-3.58; marginal structural model (MSM) adjusted odds ratio (adjOR) 3.01, 95% CI 1.47-6.16] and OCPs (Cox adjHR 2.09, 95% CI 0.75-5.84; MSM adjOR 2.35, 95% CI 0.79-6.95) generated elevated point estimates, but only estimates for injectables were significant. Findings from 11 indirect studies assessing various hormonal contraception methods and viral genital shedding or setpoint were mixed, and seven of eight studies indicated no adverse effect of various hormonal contraception methods on plasma viral load.

CONCLUSION

The only direct study on OCPs or injectable contraception and female-to-male HIV transmission suggests increased risk with the use of injectables. Given the potential for confounding in observational data, the paucity of direct evidence on this subject, and mixed indirect evidence, additional evidence is needed.

HIV infection and sexual partnerships and behaviour among adolescent girls in Nairobi, Kenya

Early sexual partnerships place young women in sub-Saharan Africa at high risk for HIV. Few studies have examined both individual- and partnership-level characteristics of sexual relationships among adolescent girls. A cross-sectional survey of sexual history and partnerships was conducted among 761 adolescent girls aged 15-19 years in Nairobi, Kenya. Rapid HIV testing was conducted and correlates of HIV infection were determined using multivariate logistic regression. The HIV prevalence was 7% and seropositive adolescents had a younger age at sexual debut (P < 0.01), more sexual partners in 12 months (P = 0.03), and were more likely to report transactional or non-consensual sex (P < 0.01). Girls who reported not knowing their partner's HIV status were 14 times as likely to be HIV-seropositive than girls who knew their partner's status (adjusted odds ratio: 14.2 [1.8, 109.3]). Public health messages to promote HIV testing and disclosure within partnerships could reduce sexual risk behaviours and HIV transmission among adolescents.

Adherence and acceptability in MTN 001: a randomized cross-over trial of daily oral and topical tenofovir for HIV prevention in women

We compared adherence to and acceptability of daily topical and oral formulations of tenofovir (TFV) used as pre-exposure prophylaxis (PrEP) for HIV prevention among women in South Africa, Uganda and the United States. 144 sexually active, HIV-uninfected women participated in a cross-over study of three regimens: oral tablet, vaginal gel, or both. We tested for differences in adherence and evaluated product acceptability. Self-reported adherence for all regimens was high (94 %), but serum TFV concentrations indicated only 64 % of participants used tablets consistently. Most women in the U.S. (72 %) favored tablets over gel; while preferences varied at the African sites (42 % preferred gel and 40 % tablets). Findings indicate a role for oral and vaginal PrEP formulations and highlight the importance of integrating pharmacokinetics-based adherence assessment in future trials. Biomedical HIV prevention interventions should consider geographic and cultural experience with product formulations, partner involvement, and sexual health benefits that ultimately influence use.

Randomized controlled trial on the effectiveness of counseling messages for avoiding unprotected sexual intercourse during sexually transmitted infection and reproductive tract infection treatment among female sexually transmitted infection clinic patients

BACKGROUND

The effectiveness of counseling messages to avoid unprotected sex during short-term treatment for curable sexually transmitted infections is unknown.

METHODS

We randomized 300 female STI clinic patients 18 years or older with cervicitis and/or vaginal discharge in Kingston, Jamaica, in 2010 to 2011, to 1 of 2 counseling messages for their course of syndromic treatment: abstinence only or abstinence backed up by condom use. At a follow-up visit 6 days afterward, we collected vaginal swabs to test for prostate-specific antigen (PSA), a biological marker of recent semen exposure, and administered a questionnaire assessing sexual behavior.

RESULTS

No differences were found in the proportions of women testing positive for PSA at follow-up in the abstinence-plus-condom group (11.9%) and abstinence-only group (8.4%) (risk difference, 3.5; 95% confidence interval, -3.5 to 10.5). There also was no significant difference in reporting of unprotected sex between groups. Reporting a history of condom use before enrollment significantly modified the effect of counseling arm on PSA positivity (P = 0.03). Among those reporting recent condom use, 10.3% in the abstinence-only arm and 4.8% in the abstinence-plus-condom arm tested positive for PSA. Conversely, among those not reporting recent condom use, 6.5% in the abstinence-only arm and 17.3% in the abstinence-plus-condom arm had PSA detected.

CONCLUSIONS

We found no evidence to support the superiority of either counseling message. Post hoc analyses suggest that women with recent condom experience may benefit significantly more from abstinence-plus-condom messages, whereas women without such experience may benefit significantly more from abstinence-only messages. Providers should weigh individual condom use history when determining the most appropriate counseling message.

Accuracy of HIV-related risk behaviors reported by female sex workers, Iran: a method to quantify measurement bias in marginalized populations

We quantified discrepancies in reported behaviors of female sex workers (FSW) by comparing 63 face-to-face interviews (FTFI) to in-depth interviews (IDI), with corroboration of the directions and magnitudes of reporting by a panel of psychologists who work with FSW. Sensitivities, specificities, positive and negative predictive values (PPV and NPV) were assessed for FTFI responses using IDI as a "gold standard". Sensitivities were lowest in reporting symptoms of sexually transmitted infections (63.9 %), finding sex partners in venues (52.4 %) and not receiving HIV test results (66.7 %). Specificities (all >83 %) and PPVs (all >74.0 %) were higher than NPV. FSW significantly under-reported number of clients, sexual contacts and non-condom use sex acts with clients and number of days engaging in sex work in the preceding week. This study provides a quantified gauge of reporting biases in FSW behaviors. Such estimates and methods help better understand true HIV risk in marginalized populations and calibrate survey estimates accordingly.

The effect of interview method on self-reported sexual behavior and perceptions of community norms in Botswana

Since self-reports of sensitive behaviors play an important role in HIV/AIDS research, the accuracy of these measures has often been examined. In this paper we (1) examine the effect of three survey interview methods on self-reported sexual behavior and perceptions of community sexual norms in Botswana, and (2) introduce an interview method to research on self-reported sexual behavior in sub-Saharan Africa. Comparing across these three survey methods (face-to-face, ballot box, and randomized response), we find that ballot box and randomized response surveys both provide higher reports of sensitive behaviors; the results for randomized response are particularly strong. Within these overall patterns, however, there is variation by question type; additionally the effect of interview method differs by sex. We also examine interviewer effects to gain insight into the effectiveness of these interview methods, and our results suggest that caution be used when interpreting the differences between survey methods.

Exploring discordance between biologic and self-reported measures of semen exposure: a qualitative study among female patients attending an STI clinic in Jamaica

We explored the use of qualitative interviews to discuss discrepancies between two sources of information on unprotected sex: biomarker results and self-reported survey data. The study context was a randomized trial in Kingston, Jamaica examining the effect of STI counseling messages on recent sexual behavior using prostate-specific antigen (PSA) as the primary study outcome. Twenty women were interviewed. Eleven participants were selected because they tested positive for PSA indicating recent semen exposure, yet reported no unprotected sex in a quantitative survey ("discordant"): 5 reported abstinence and 6 reported condom use. Nine participants who also tested positive for PSA but reported unprotected sex in the survey were interviewed for comparison ("concordant"). Qualitative interviews with 6 of the 11 discordant participants provided possible explanations for their PSA test results, and 5 of those were prompted by direct discussion of those results. Rapid PSA testing combined with qualitative interviews provides a novel tool for investigating and complementing self-reported sexual behavior.

Effect of computer-assisted interviewing on self-reported sexual behavior data in a microbicide clinical trial

In a microbicide safety and effectiveness trial (HPTN 035) in Malawi, 585 women completed the same questionnaire through a face-to-face interview (FTFI) and an audio computer-assisted self-interview (ACASI). Concordance between FTFI and ACASI responses ranged from 72.0 % for frequency of sex in the past week to 95.2 % for anal intercourse (AI) in the past 3 months. Reported gel and condom use at last sex act were marginally lower with ACASI than FTFI (73.5 % vs. 77.2 %, p = 0.11 and 60.9 % vs. 65.5 %, p = 0.05, respectively). More women reported AI with ACASI than FTFI (5.0 % vs. 0.2 %, p < 0.001). Analyses of consistency of responses within ACASI revealed that 15.0 % of participants in the condom-only arm and 28.7 % in the gel arm provided at least one discrepant answer regarding total sex acts and sex acts where condom and gel were used (19.2 % reported one inconsistent answer, 8.1 % reported two inconsistent answers, and 1.4 % reported three inconsistent answers). While ACASI may provide more accurate assessments of sensitive behaviors in HIV prevention trials, it also results in a high level of internally inconsistent responses.

TSPY4 is a novel sperm-specific biomarker of semen exposure in human cervicovaginal fluids; potential use in HIV prevention and contraception studies

BACKGROUND

Developing an objective, reliable method to determine semen exposure in cervicovaginal fluids is important for accurately studying the efficacy of vaginal microbicides and contraceptives. Y-chromosome biomarkers offer better stability, sensitivity, and specificity than protein biomarkers. TSPY4 belongs to the TSPY (testis-specific protein Y-encoded) family of homologous genes on the Y-chromosome. Using a multiplex PCR amplifying TSPY4, amelogenin, and Sex-determining region in the Y chromosome (SRY), our objective was to determine whether a gene in the TSPY family was a more sensitive marker of semen exposure in cervicovaginal fluids than SRY.

STUDY DESIGN

The multiplex polymerase chain reaction (PCR) was developed using sperm and vaginal epithelial (female) DNA. Diluted sperm DNA and mixed male/female DNA was used to determine the sensitivity of the multiplex PCR. Potential interference of TSPY4 amplification by components in cervicovaginal and seminal fluids was determined. TSPY4 and SRY amplification was also investigated in women participating in a separate IRB-approved clinical study in which cervicovaginal swab DNA was collected before semen exposure and at various time points after exposure.

RESULTS

TSPY4, SRY, and amelogenin were amplified in sperm DNA, but only amelogenin in female DNA. The limit of sperm DNA from which TSPY4 could be amplified was lower than SRY (4 pg vs 80 pg). TSPY4 could also be amplified from mixed male/female DNA. Amplification was not affected by cervicovaginal and seminal components. Using cervicovaginal swab DNA from three women before and after semen exposure, TSPY4 was detected up to 72 h post exposure while SRY detection was observed up to 24-48 h. TSPY4 was detected up to 7 days post exposure in one out of three women.

CONCLUSIONS

We have demonstrated that TSPY4 is a new sensitive, and sperm-specific biomarker. The multiplex PCR incorporating this new biomarker has potential to be an objective measure for determining semen exposure in clinical trials of vaginal products such as contraceptives and HIV pre/post-exposure prophylaxis agents.

Effect of topical vaginal products on the detection of prostate-specific antigen, a biomarker of semen exposure, using ABAcards

BACKGROUND

Prostate-specific antigen (PSA) is a biomarker of recent semen exposure. There is currently only limited information on whether topical vaginal products affect PSA assays. We investigated this question using various dilutions of several vaginal products (lubricants and spermicides) and the Abacus ABAcard for PSA detection.

STUDY DESIGN

Pooled semen controls and various dilutions of nonoxynol-9 (N9), carboxymethyl cellulose (CMC), Replens, Gynol 2, K-Y jelly, Astroglide, Surgilube, combined with pooled semen dilutions, were tested for PSA using the Abacus ABAcard.

RESULTS

N9 (2% with saline) and CMC did not appear to affect the results of testing with the ABAcard, but not all semen dilutions were tested. The other products (including Replens and Gynol, which is 2% N9 with propylene glycol, K-Y, Astroglide and Surgilube) at some of the dilutions tested either affected or gave invalid results with PSA testing using the ABAcard. Both Gynol 2 and K-Y at 1:10 dilution gave false-positive results.

CONCLUSIONS

Some vaginal products affect PSA results obtained by using the semiquantitative ABAcard. In vivo confirmation is necessary to further optimize PSA detection when topical vaginal products are present.