Sexual transmission of HIV-1

Associations of Sleep Deficiency With Sexual Risk Behaviors and HIV Treatment Outcomes Among Men Who Have Sex With Men Living With or at High Risk of Acquiring HIV

BACKGROUND

Associations of sleep deficiency and methamphetamine use with sexual health and HIV treatment outcomes are poorly understood.

SETTING

A longitudinal cohort of men who have sex with men at risk for or living with HIV (the mSTUDY) was analyzed. This analysis included 1445 study visits among 382 participants. Data were collected from June 2018 to February 2022.

METHODS

Semiannual study visits included self-interviews for sleep deficiency, sexual behaviors, substance use, and HIV treatment. Sleep deficiency was measured using the Pittsburgh Sleep Quality Index. Participants provided specimens for HIV viral load and sexually transmitted infection (STI) testing (chlamydia, gonorrhea, syphilis). Associations between sleep deficiency and STI/HIV outcomes were estimated using multiple logistic regression.

RESULTS

Across visits, the prevalence of sleep deficiency was 56%, with 33% reporting methamphetamine use and 55% living with HIV. Sleep deficiency was associated with reporting at least 1 new anal sex partner (aOR = 1.62, 95% CI: 1.21 to 2.15), exchange sex (aOR = 2.71, 95% CI: 1.15 to 6.39), sex party attendance (aOR = 2.60, 95% CI: 1.68 to 4.04), and missing HIV medications (aOR = 1.91, 95% CI: 1.16 to 3.14). The association between sleep deficiency and exchange sex differed for participants who did and did not report the use of methamphetamine (P = 0.09).

CONCLUSION

Sleep deficiency was associated with sexual health and HIV treatment behaviors after accounting for methamphetamine use. Sleep health should be considered in STI/HIV prevention, particularly for those who use methamphetamine.

HIV seroconversion and associated factors among seronegative pregnant women attending ANC in Ethiopia: an institution-based cross-sectional study

Background

In countries with limited resources, including Ethiopia, HIV is diagnosed using a rapid serological test, which does not detect the infection during the window period. Pregnant women who test negative for HIV on the first test may seroconvert throughout pregnancy. Women who are seroconverted during pregnancy may not have received interventions, as they are considered HIV-negative unless they are retested for HIV at the end of their pregnancy. Due to limited data on HIV seroconversion, this study aimed to measure the extent of HIV seroconversion and to identify associated factors among seronegative pregnant women attending ANC in Ethiopia.

Methods

Institution-based cross-sectional study was conducted among HIV-negative pregnant women attending the ANC in Ethiopia between June and July 2020. Socio-demographic, clinical, and behavioral data were collected through face-to-face questionnaires and participants' records review. HIV retesting was performed to determine the current HIV status of pregnant women. The data collected were entered into Epi data version 4.4.1 and were exported and analyzed by SPSS version 25. A p-value < 0.25 in the bivariate analysis was entered into multivariable logistic regression analysis and a p-value of < 0.05 was considered statistically significant.

Result

Of the 494 pregnant women who tested negative for HIV on their first ANC test, six (1.2%) tested positive on repeat testing. Upon multivariable logistic regression, pregnant women who have had a reported history of sexually transmitted infections [AOR = 7.98; 95% CI (1.21, 52.82)], participants' partners reported travel history for work frequently [AOR = 6.00; 95% CI (1.09, 32.99)], and sexually abused pregnant women [AOR = 7.82; 95% CI (1.194, 51.24)] were significantly associated with HIV seroconversion.

Conclusion

The seroconversion rate in this study indicates that pregnant women who are HIV-negative in early pregnancy are at an ongoing risk of seroconversion throughout their pregnancy. Thus, this study highlights the benefit of a repeat HIV testing strategy in late pregnancy, particularly when the risk of seroconversion or new infection cannot be convincingly excluded. Therefore, repeated testing of HIV-negative pregnant women in late pregnancy provides an opportunity to detect seroconverted pregnant women to enable the timely use of ART to prevent mother-to-child transmission of HIV infection.

Syphilis Diagnosis After a Chlamydia, Gonorrhea, or HIV Diagnosis Among Reproductive-Aged Women in Baltimore, MD

BACKGROUND

Syphilis incidence is increasing among reproductive-aged women, and previous sexually transmitted infections (STIs) are a risk factor for subsequent STIs. This study aimed to determine syphilis incidence after a chlamydia, gonorrhea, or HIV diagnosis, and identify characteristics associated with higher syphilis incidence rates among reproductive-aged women in 1 mid-Atlantic city.

METHODS

A retrospective cohort of 85,113 chlamydia, gonorrhea, and HIV diagnoses occurring between 2009 and 2021 and among women aged 13 to 50 years was constructed using public health surveillance data. Cumulative incidence curves were estimated to examine time to early syphilis (i.e., primary, secondary, or early latent) diagnosis, and multivariable analyses determined incidence rate ratios by age (<25 vs. ≥25 years) and number of prior STI diagnoses (0 vs. ≥1) during the study period, stratified by STI.

RESULTS

There were 85,113 reportable STI diagnoses and 646 syphilis diagnoses in the cohort. Approximately 1 of 150 chlamydia, 1 of 100 gonorrhea, and 1 of 50 HIV diagnoses were followed by a syphilis diagnosis within 5 years. Cumulative incidence of syphilis differed significantly by STI diagnosis ( P < 0.001). In multivariable analysis, syphilis incidence rates were higher among women diagnosed with ≥1 (vs. 0) prior STI regardless of STI type ( P < 0.05) and among women ≥25 (vs. <25) years old diagnosed with gonorrhea ( P < 0.05).

CONCLUSIONS

There were significant differences in syphilis incidence by prior STI type, number of STIs, and age. Our data support targeted screening for syphilis among women with a history of STIs, parwomen with ≥1 prior STI diagnosis, and older women diagnosed with gonorrhea.

High syphilis prevalence and incidence in people living with HIV and Preexposure Prophylaxis users: A retrospective review in the French Dat’AIDS cohort

Background

In the past years, we observed a sharp increase of Syphilis, especially among male who have sex with male (MSM), either HIV-infected, or on pre-exposure prophylaxis (PrEP). Our aim was to assess syphilis prevalence and incidence among people living with HIV (PLWH) and PrEP users.

Methods

PLWH were included from 2010 to 2020 and PrEP users from 2016 to 2020 from the Dat’AIDS French cohort. We calculated syphilis prevalence and incidences for first infections, re-infections, and iterative infections (> 2 times). T-Tests, Wilcoxon tests and Chi2 test were used for descriptive analysis and multivariate logistic regression models were used to estimate Odds ratios (OR) and 95% confidence intervals (95% CI) for factors associated with syphilis.

Results

Among the 8 583 PLWH, prevalence of subject with past or present syphilis was 19.9%. These subjects were more likely MSM or transgender and aged over 35 years, but prevalence was lower in AIDS subjects. Same pattern was seen for incident infection and re-infection. Incidence was 3.8 per 100 person-years for infection and 6.5 per 100 person-years for re-infection. Among 1 680 PrEP users, syphilis prevalence was 25.8%, with an estimated 7.2% frequency of active syphilis. Risk of syphilis infection was higher in male and increased with age. Incidence was 11.2 per 100 person-years for infection and 11.1 per 100 person-years for re-infection.

Conclusion

Syphilis prevalence and incidence were high, especially in older MSM with controlled HIV infection and PrEP users, enhancing the need to improve syphilis screening and behavioral risk reduction counseling among high-risk subjects.

Lubrication Practices and Receptive Anal Sex: Implications for STI Transmission and Prevention

INTRODUCTION

Implications of lubricant use in men having sex with men (MSM) are poorly characterized, particularly associations with sexual behavior and rectal sexually transmitted infection (STI) risk.

AIM

We sought to clarify covariates associated with lubrication type including differing sexual preferences and rectal STI prevalence.

METHODS

Primary English-speaking individuals ≥18 years old visiting San Francisco City Clinic (SFCC) between April and May of 2018 who endorsed lubricant use during receptive anal sex within the last 3 months were studied. Associations between lubrication type used and collected covariates were assessed using Kruskal-Wallis analysis of variance for continuous variables and Chi-squared test for categorical variables. We used logistic regression to examine the association between lubrication type and rectal STI test result.

MAIN OUTCOME MEASURES

Rectal STI test positivity.

RESULTS

From all enrolled participants, 179 completed the survey and endorsed use of a lubricant during receptive anal sex within the last 3 months. Silicone lubricant users had the most sexual partners in the last 3 months (13 [mean] ± 30 [SD], P= .0003) and were most likely to have a history of gonorrhea. Oil-based lubricant users had the most partners with whom they had receptive anal sex in the last 3 months (7 ± 6, P= .03). Water-based lubricant users most commonly used a condom in their last sexual encounter and had the fewest sexual partners in the last 3 months (4 ± 4, P= .0003). Spit/saliva lubricant use was associated with positive rectal STI result.

CONCLUSION

Silicone and oil-based lubricant users were more likely to report condomless receptive anal sex and to have a history of gonorrhea while spit/saliva lubricant use associated with positive rectal STI acquisition. Lee A, Gaither TW, Langston ME, et al. Lubrication Practices and Receptive Anal Sex: Implications for STI Transmission and Prevention. Sex Med 2021;9:100341.

HIV susceptibility in women: The roles of genital inflammation, sexually transmitted infections and the genital microbiome

Given that heterosexual transmission of HIV across the genital mucosa is the most common route of infection in women, an in-depth understanding of the biological mechanisms associated with HIV risk in the female genital tract (FGT) is essential for effective control of the epidemic. Genital pro-inflammatory cytokines are well-described biological co-factors to HIV risk. Increased levels of pro-inflammatory cytokines in the FGT have been associated with a 3-fold higher-risk of acquiring HIV, presumably through involvement in barrier compromise and the recruitment of highly activated HIV target cells to the site of initial viral infection and replication. Sexually transmitted infections (STIs) and bacterial vaginosis (BV) are suggested possible contributors to genital inflammation in the FGT, and this, coupled with the relationship between genital inflammation and HIV risk, underscores the importance of effective treatment of STI and BV in the promotion of women's health. In most low- and middle-income countries, STIs are treated syndromically, a practice providing rapid treatment without identifying the infection source. However, this approach has been associated with over-diagnosis and the overuse of drugs. Further, because many women with STIs are asymptomatic, syndromic management also fails to treat a vast proportion of infected women. Although several studies have explored the role of STIs and the vaginal microbiome on genital inflammation and HIV risk, the impact of STI and BV management on genital inflammation remains poorly understood. This review aimed to collate the evidence on how BV and STI management efforts affect genital inflammation and the genital microbiome in women.

Avoiding missed opportunities to screen for HIV

HIV transmission is ongoing, primarily among men who have sex with men, injection drug users, and persons from HIV endemic regions. One prevention strategy has been prompt HIV diagnosis. Undermining these efforts is that some persons are diagnosed with HIV late in their infection because practitioners missed the diagnosis. In this article, the authors review the epidemiology and pathophysiology of HIV/AIDS, and provide a recommended clinical approach: (1) continue to screen persons who belong to the groups that are at-risk for HIV, and (2) appropriately rule out HIV infection in persons who present with HIV and AIDS-like symptoms.

Infection with multiple HIV-1 founder variants is associated with lower viral replicative capacity, faster CD4+ T cell decline and increased immune activation during acute infection

HIV-1 transmission is associated with a severe bottleneck in which a limited number of variants from a pool of genetically diverse quasispecies establishes infection. The IAVI protocol C cohort of discordant couples, female sex workers, other heterosexuals and men who have sex with men (MSM) present varying risks of HIV infection, diverse HIV-1 subtypes and represent a unique opportunity to characterize transmitted/founder viruses (TF) where disease outcome is known. To identify the TF, the HIV-1 repertoire of 38 MSM participants' samples was sequenced close to transmission (median 21 days post infection, IQR 18-41) and assessment of multivariant infection done. Patient derived gag genes were cloned into an NL4.3 provirus to generate chimeric viruses which were characterized for replicative capacity (RC). Finally, an evaluation of how the TF virus predicted disease progression and modified the immune response at both acute and chronic HIV-1 infection was done. There was higher prevalence of multivariant infection compared with previously described heterosexual cohorts. A link was identified between multivariant infection and replicative capacity conferred by gag, whereby TF gag tended to be of lower replicative capacity in multivariant infection (p = 0.02) suggesting an overall lowering of fitness requirements during infection with multiple variants. Notwithstanding, multivariant infection was associated with rapid CD4+ T cell decline and perturbances in the CD4+ T cell and B cell compartments compared to single variant infection, which were reversible upon control of viremia. Strategies aimed at identifying and mitigating multivariant infection could contribute toward improving HIV-1 prognosis and this may involve strategies that tighten the stringency of the transmission bottleneck such as treatment of STI. Furthermore, the sequences and chimeric viruses help with TF based experimental vaccine immunogen design and can be used in functional assays to probe effective immune responses against TF.

High Rates of Unprotected Receptive Anal Intercourse and Their Correlates Among Young and Older MSM in Brazil

The aim of this study was to estimate the prevalence and factors associated with unprotected receptive anal intercourse (URAI), stratified by age (18-24 or 25 + years old), in a sample of 4,129 MSM recruited by respondent driven sampling in 12 Brazilian cities in 2016. The prevalence of URAI was higher among younger MSM (41.9% vs 29.7%) (p < 0.01). Multivariate analysis indicated that perception of risk, sexual identity, self-rated health status, and having commercial sex were associated with URAI among younger MSM. History of sexual violence, sex with younger partners, having 6 + partners and unprotected sexual debut were associated with URAI among older MSM. Marital status, having stable partner, and reporting sex with men only were associated with URAI in both groups. Despite access to condoms and lubricants, preventive efforts may not be reaching MSM effectively. Age specific intervention approaches, including stigma, discrimination, and perception of risk must be considered.

A Nonhuman Primate Model for Rectally Transmitted Syphilis

Among men who have sex with men (MSM), those with a diagnosis of syphilis or other rectal sexually transmitted infections (STIs) are at a higher risk for human immunodeficiency virus acquisition, which is concerning given the large increase in recently reported syphilis cases in the United States. We have developed the first nonhuman primate model for rectally transmitted syphilis by exposing simian/human immunodeficiency virus-infected and naive rhesus macaques to Treponema pallidum in the rectum. All animals showed mucosal lesions, systemic dissemination, and seroconversion (treponemal antibodies). This model would be valuable for studying the manifestations of and interventions for T. pallidum infection, with and without human immunodeficiency virus coinfection.

Anal Ureaplasma spp. positivity among HIV positive men who have sex with men may be associated with high-risk-type HPV infections

OBJECTIVE

HIV positive individuals, particularly men having sex with men (MSM), are at increased risk of sexually transmitted infections (STIs) at genital and extra-genital sites. Data on anorectal Ureaplasma infections are lacking. The aim of our study was to characterize anal Ureaplasma positivity among a cohort of HIV positive MSM and evaluate possible association with papillomavirus infection at the same site.

METHODS

Anal swab samples, collected as part of routine screening for Chlamydia trachomatis and Neisseria gonorrhea, were additionally tested for HPV genotypes as well as for Ureaplasma and Mycoplasma using nucleic acid amplification method.

RESULTS

Out of a total of 222 study participants, 195 (89%, 95% CI (84.9-93.2)) were positive for HPV, approximately three quarter being high-risk genotypes. Forty three individuals (19.4%, 95% CI (14.4-24.3)) harbored Ureaplasma spp. Infection with high-risk HPV types was significantly associated with co-presence of Ureaplasma with an odds ratio (95% confidence-interval) of 2.59 (1.03-6.54), P = 0.04.

CONCLUSION

Besides a high predominance of HPV infection, asymptomatic HIV positive MSM had a high prevalence of anal Ureaplasma positivity. Concomitant infections with high-risk HPV genotypes were common and statistically significant. The role of this co-existence as a potential risk factor for anal carcinogenesis needs further elucidation.

Venue-Based HIV-Testing: An Effective Screening Strategy for High-Risk Populations in Lima, Peru

Venue-based testing may improve screening efforts for HIV and syphilis, thereby reducing transmission. We offered onsite rapid dual HIV and syphilis testing at venues popular among MSM and/or transgender women in Lima, Peru. We used Poisson regression to calculate adjusted prevalence ratios (aPRs) for factors associated with each infection. Most (90.4%) of the 303 participants would test more frequently if testing was available at alternative venues. New cases of HIV (69) and syphilis infection (84) were identified. HIV was associated with recent sex work (aPR 1.11; 95% CI 1.02-1.22), sex with a partner of unknown serostatus (aPR 1.18; 95% CI 1.09-1.27), exclusively receptive anal sex role (aPR 1.16; 95% CI 1.03-1.30) or versatile sex role (aPR 1.17; 95% CI 1.06-1.30) compared to insertive. Syphilis was associated with reporting role versatility (aPR = 2.69; 95% CI 1.52-5.74). Sex work venues had higher syphilis prevalence 47% versus 28% in other venues, p value = 0.012. Venue-based testing may improve case finding.

Characterizing HIV risk among cisgender men in Latin America who report transgender women as sexual partners: HIV risk in Latin America men

Cisgender men (CM) who report transgender women (TW) as sexual partners are an understudied population in the HIV epidemic in Latin America. The current study sought to characterize this group in a 2012 cross-sectional online survey of Latin American CM who were members of a sexual networking website for men who have sex with men (N = 11,847). Multivariable logistic regression models were fit to estimate demographic, behavioral, and psychosocial correlates of having a TW sexual partner and engaging in condomless sex. Overall, 0.9% (n = 106) reported a TW sexual partner in the last 12 months; of these, 76.4% (n = 81) reported condomless sex in the last three months. Identifying as bisexual or heterosexual compared to gay, and specifying a versatile sexual role preference compared to insertive were associated with reporting a recent TW sex partner (all p < 0.05). HIV-negative serostatus, lifetime STI history, and alcohol dependence were associated with recent condomless sex (all p < 0.05). CM with TW sexual partners have distinct HIV-related vulnerabilities. Future research is needed to understand CM who report TW sexual partners, including their sexual preferences and practices, sexual networks, exposure to stigma, biomedical prevention interest and uptake, and acceptability of integrating alcohol abuse screening into sexual health services.

Link between the numbers of particles and variants founding new HIV-1 infections depends on the timing of transmission

Understanding which HIV-1 variants are most likely to be transmitted is important for vaccine design and predicting virus evolution. Since most infections are founded by single variants, it has been suggested that selection at transmission has a key role in governing which variants are transmitted. We show that the composition of the viral population within the donor at the time of transmission is also important. To support this argument, we developed a probabilistic model describing HIV-1 transmission in an untreated population, and parameterised the model using both within-host next generation sequencing data and population-level epidemiological data on heterosexual transmission. The most basic HIV-1 transmission models cannot explain simultaneously the low probability of transmission and the non-negligible proportion of infections founded by multiple variants. In our model, transmission can only occur when environmental conditions are appropriate (e.g. abrasions are present in the genital tract of the potential recipient), allowing these observations to be reconciled. As well as reproducing features of transmission in real populations, our model demonstrates that, contrary to expectation, there is not a simple link between the number of viral variants and the number of viral particles founding each new infection. These quantities depend on the timing of transmission, and infections can be founded with small numbers of variants yet large numbers of particles. Including selection, or a bias towards early transmission (e.g. due to treatment), acts to enhance this conclusion. In addition, we find that infections initiated by multiple variants are most likely to have derived from donors with intermediate set-point viral loads, and not from individuals with high set-point viral loads as might be expected. We therefore emphasise the importance of considering viral diversity in donors, and the timings of transmissions, when trying to discern the complex factors governing single or multiple variant transmission.

The role of sexual networks in studies of how BV and STIs increase the risk of subsequent reinfection

Prior studies have demonstrated that both bacterial vaginosis (BV) and sexually transmitted infections (STIs) are strong independent risk factors for subsequent STI. In observational studies of this biological enhancement (BE) hypothesis, it is important to adjust for the risk of STI exposure so that the independent effect of BE can be assessed. We sought to model if two markers of local sexual network (partner concurrency and cumulative number of STIs) represented residual confounding in the models of risk for subsequent infection in a study that screened 3620 women for STIs every 3 months for a year. Mixed-effects logistic regression was used to calculate the odds ratios for an incident diagnosis of Chlamydia trachomatis, Neisseria gonorrhoeae, Trichomonas vaginalis and BV following a diagnosis of any of these four at the prior visit, controlling for the cumulative number of STIs and partner concurrency variables. We found that partner concurrency and cumulative number of STIs were each associated with incident infection, and in general, controlling for these variables reduced the strength of the association between prior and incident infections. We conclude that the frequently found association between prior and incident STIs is associated with both BE and sexual network structure.

Antiviral Activity of Tannic Acid Modified Silver Nanoparticles: Potential to Activate Immune Response in Herpes Genitalis

(1) Background: Tannic acid is a plant-derived polyphenol showing antiviral activity mainly because of an interference with the viral adsorption. In this work, we tested whether the modification of silver nanoparticles with tannic acid (TA-AgNPs) can provide a microbicide with additional adjuvant properties to treat genital herpes infection. (2) Methods: The mouse model of the vaginal herpes simplex virus 2 (HSV-2) infection was used to test immune responses after treatment of the primary infection with TA-AgNPs, and later, after a re-challenge with the virus. (3) Results: The mice treated intravaginally with TA-AgNPs showed better clinical scores and lower virus titers in the vaginal tissues soon after treatment. Following a re-challenge, the vaginal tissues treated with TA-AgNPs showed a significant increase in the percentages of IFN-gamma+ CD8+ T-cells, activated B cells, and plasma cells, while the spleens contained significantly higher percentages of IFN-gamma+ NK cells and effector-memory CD8+ T cells in comparison to NaCl-treated group. TA-AgNPs-treated animals also showed significantly better titers of anti-HSV-2 neutralization antibodies in sera; and (4) Conclusions: Our findings suggest that TA-AgNPs sized 33 nm can be an effective anti-viral microbicide to be applied upon the mucosal tissues with additional adjuvant properties enhancing an anti-HSV-2 immune response following secondary challenge.

The patient rationale for seeking HIV PEP: Qualitative results from a nurse-led program

BACKGROUND

HIV PEP is an intervention to prevent HIV seroconversion among HIV-negative persons after they have come into contact with the virus. The literature suggests PEP is greater than 80% effective at reducing HIV seroconversion. To expand access to this prevention strategy, we established a nurse-led PEP program in two STI clinics.

AIMS

We sought to explore why people seek PEP, and their experiences using it.

MATERIALS & METHODS

We invited participants who used our PEP program to engage in semi-structured qualitative interviews. These were audio-recorded, transcribed verbatim, and analyzed using the techniques of thematic analysis.

RESULTS

Twelve men who initiated PEP through our program participated in an interview. Thematic analysis of the data identified three themes: (1) assessing risk, (2) euphoria and distress, and (3) reducing distress.

DISCUSSION

Based on our findings, it appears as though instances of condomless sex were atypical and unplanned, they occurred due to contextual factors (e.g., consent, desire to explore, sexual chemistry/intensity), and they resulted in a state of temporary euphoria, which, afterward, transformed into distress (i.e., "feel[ing] stupid"). The participants used PEP not only for HIV prevention, but also (and perhaps more so) to address their emotional state. PEP used seemed to primarily occur to address situations of atypical sexual contact with partners they did not "know" or "trust".

CONCLUSION

We feel these results help contextualize how potential PEP users view HIV risk assessments, and how they determine their need for this intervention.

Risk behavior score: a practical approach for assessing risk among men who have sex with men in Brazil

HIV/AIDS epidemic is not well controlled, and multiple sexual behavior factors help explain high rates of HIV infection among men who have sex with men (MSM). This article proposes to exam the use of a potential risk behavior score for HIV infection, based on the type and number of sexual partners, and condom use, and their associated factors in a sample of MSM in Brazil. A cross sectional RDS (Respondent Driven Sampling) study was performed among 3738 MSM aged 18+ years old from ten Brazilian cities. The risk behavior score was composed by the number of male partners and anal condom use in the last year with steady, casual, and commercial partners. Most participants were 25+ years old (58.1%), non-white (83.1%), and single (84.9%). Final weighted ordinal logistic model showed that age ≤ 25 years old (p = 0.037), homosexual or bisexual identity (p < 0.001), sexual initiation before 15-year-old (p < 0.001), having sex with men only in the last 12 months (p < 0.001), frequent alcohol and illicit drug use (p < 0.001), and use of local sites to meet sexual partners in the last month were independently associated with higher scores of risky behavior. Specific strategies should be developed aimed at the MSM population. Additionally, pre-exposed prophylaxis (Prep) should be considered for those at higher score as a strategy for reducing risk for HIV infection in this population.

Prevalence of sexually transmitted infections and bacterial vaginosis among women in sub-Saharan Africa: An individual participant data meta-analysis of 18 HIV prevention studies

BACKGROUND

Estimates of sexually transmitted infection (STI) prevalence are essential for efforts to prevent and control STIs. Few large STI prevalence studies exist, especially for low- and middle-income countries (LMICs). Our primary objective was to estimate the prevalence of chlamydia, gonorrhea, trichomoniasis, syphilis, herpes simplex virus type 2 (HSV-2), and bacterial vaginosis (BV) among women in sub-Saharan Africa by age, region, and population type.

METHODS AND FINDINGS

We analyzed individual-level data from 18 HIV prevention studies (cohort studies and randomized controlled trials; conducted during 1993-2011), representing >37,000 women, that tested participants for ≥1 selected STIs or BV at baseline. We used a 2-stage meta-analysis to combine data. After calculating the proportion of participants with each infection and standard error by study, we used a random-effects model to obtain a summary mean prevalence of each infection and 95% confidence interval (CI) across ages, regions, and population types. Despite substantial study heterogeneity for some STIs/populations, several patterns emerged. Across the three primary region/population groups (South Africa community-based, Southern/Eastern Africa community-based, and Eastern Africa higher-risk), prevalence was higher among 15-24-year-old than 25-49-year-old women for all STIs except HSV-2. In general, higher-risk populations had greater prevalence of gonorrhea and syphilis than clinic/community-based populations. For chlamydia, prevalence among 15-24-year-olds was 10.3% (95% CI: 7.4%, 14.1%; I2 = 75.7%) among women specifically recruited from higher-risk settings for HIV in Eastern Africa and was 15.1% (95% CI: 12.7%, 17.8%; I2 = 82.3%) in South African clinic/community-based populations. Among clinic/community-based populations, prevalence was generally greater in South Africa than in Southern/Eastern Africa for most STIs; for gonorrhea, prevalence among 15-24-year-olds was 4.6% (95% CI: 3.3%, 6.4%; I2 = 82.8%) in South Africa and was 1.7% (95% CI: 1.2%, 2.6%; I2 = 55.2%) in Southern/Eastern Africa. Across the three primary region/population groups, HSV-2 and BV prevalence was high among 25-49-year-olds (ranging from 70% to 83% and 33% to 44%, respectively). The main study limitation is that the data are not from random samples of the target populations.

CONCLUSIONS

Combining data from 18 HIV prevention studies, our findings highlight important features of STI/BV epidemiology among sub-Saharan African women. This methodology can be used where routine STI surveillance is limited and offers a new approach to obtaining critical information on STI and BV prevalence in LMICs.

Lubricant Use and Rectal Chlamydial and Gonococcal Infections Among Men Who Engage in Receptive Anal Intercourse

BACKGROUND

Use of lubricants during anal intercourse is very common among men who have sex with men. However, few studies have evaluated associations between specific lubricants and rectal sexually transmitted infections (STIs).

METHODS

Between July 2012 and October 2013, we conducted a cross-sectional study of men who have sex with men recruited from an urban, public sexual health clinic. In a self-administered survey, participants identified the lubricants used and frequency of lubricant use in the previous three months. Among men reporting any receptive anal intercourse (RAI) in the previous 3 months, we used multivariable binomial regression models to analyze associations between recent use of 9 specific lubricants and prevalent rectal chlamydia, rectal gonorrhea, and either rectal infection.

RESULTS

Twenty-five percent of the 146 participants had rectal chlamydial infection and 21% had rectal gonococcal infection; 37% had either (chlamydial or gonococcal) infection. Three-quarters reported always or almost always using lubricant during recent receptive anal intercourse. After adjustment for age, race, human immunodeficiency virus status, and condom use, Gun Oil (adjusted prevalence ratio [aPR], 1.99; 95% confidence interval [CI], 1.04-3.80) and Slick (aPR, 3.55; 95% CI, 1.38-9.12) were significantly associated with prevalent gonococcal infection. No lubricants were significantly associated with prevalent rectal chlamydia, but in analyses of either rectal infection, precum (aPR, 1.68; 95% CI, 1.06-2.66), Vaseline (aPR, 1.70; 95% CI, 1.10-2.64), and baby oil (aPR, 2.26; 95% CI, 1.43-3.57) were all significantly associated with prevalent rectal infection.

CONCLUSIONS

Several lubricants were significantly associated with increased prevalence of rectal STI. Longitudinal studies are needed to examine any causal relationship between specific lubricants and STI acquisition.

Strategies for Prevention and Treatment of Trichomonas vaginalis Infections

The last estimated annual incidence of Trichomonas vaginalis worldwide exceeds that of chlamydia and gonorrhea combined. This critical review updates the state of the art on advances in T. vaginalis diagnostics and strategies for treatment and prevention of trichomoniasis. In particular, new data on treatment outcomes for topical administration of formulations are reviewed and discussed.

Condomless sex and HIV transmission among serodifferent couples: current evidence and recommendations

Human immunodeficiency virus (HIV) infection remains a global pandemic. The primary driver of HIV incidence is sexual transmission between serodifferent individuals. Condoms, when used consistently and correctly, are effective at preventing sexually transmitted HIV infections and are considered an integral component of a comprehensive approach to HIV prevention. However, the demonstrated effectiveness of antiretroviral therapy (ART) to prevent HIV transmission, known as treatment as prevention and of pre-exposure prophylaxis, have raised an intriguing dilemma on the necessity and additive preventive benefit of condom use among individuals in serodifferent relationships utilizing these prevention strategies. Recent published evidence, although of limited follow-up duration, has shown no linked HIV transmissions with condomless sex among serodifferent couples where the infected partner was on ART and virologically suppressed. This paper will review the evidence surrounding HIV transmission risk among serodifferent couples with and without the use of condoms and will highlight factors that increase or attenuate this risk. It will also address the important benefits that condomless sex offers couples. This paper aims to provide a template for providers to have personalized discussions with their patients, particularly those with an HIV-positive sexual partner, around their individual risk of HIV transmission and the role of condom use.

Structural and Behavioral Correlates of HIV Infection among Pregnant Women in a Country with a Highly Generalized HIV Epidemic: A Cross-Sectional Study with a Probability Sample of Antenatal Care Facilities in Swaziland

INTRODUCTION

HIV disproportionately affects women in Sub-Saharan Africa. Swaziland bears the highest HIV prevalence of 41% among pregnant women in this region. This heightened HIV-epidemic reflects the importance of context-specific interventions. Apart from routine HIV surveillance, studies that examine structural and behavioral factors associated with HIV infection among women may facilitate the revitalization of existing programs and provide insights to inform context-specific HIV prevention interventions.

METHODS AND FINDINGS

This cross-sectional study employed a two-stage random cluster sampling in ten antenatal health care facilities in the Hhohho region of Swaziland in August and September 2015. Participants were eligible for the study if they were 18 years or older and had tested for HIV. Self-administered tablet-based questionnaires were used to assess HIV risk factors. Of all eligible pregnant women, 827 (92.4%) participated, out of which 297 (35.9%) were self-reportedly HIV positive. Among structural factors, family function was not significantly associated with self-reported HIV positive status, while lower than high school educational attainment (AOR, 1.65; CI, 1.14-3.38; P = 0.008), and income below minimum wage (AOR, 1.81; CI, 1.09-3.01; P = 0.021) were significantly associated with self-reported HIV positive status. Behavioral factors significantly associated with reporting a positive HIV status included; ≥2 lifetime sexual partners (AOR, 3.16; CI, 2.00-5.00; P<0.001), and ever cohabited (AOR, 2.39; CI, 1.66-3.43; P = 0.00). The most cited reason for having multiple sexual partners was financial gain. HIV/AIDS-related knowledge level was high but not associated to self-reported HIV status (P = 0.319).

CONCLUSIONS

Structural and behavioral factors showed significant association with self-reported HIV infection among pregnant women in Swaziland while HIV/AIDS-related knowledge and family function did not. This suggests that HIV interventions should be reinforced taking into consideration these findings. The findings also suggest the importance of future research sensitive to the Swazi and African sociocultural contexts, especially research for family function.

Sexual behaviors and partner-specific correlates of heterosexual anal intercourse among truck drivers and their wives in South India

It is important to know about patterns of sexual behaviors among married couples in order to develop effective HIV prevention strategies for them. Herein we describe the sexual behaviors, estimate prevalence of anal intercourse (AI) among truck drivers ("truckers") and their wives, and determine partner-specific demographic and behavioral correlates of AI. We carried out a cluster-sampled cross-sectional survey among 18-49 year-old wives and their trucker husbands in a south Indian district. Data were collected by same-gender research team members with color-coded computer-assisted interviews. We used random intercept logistic regression to identify the independent correlates of AI. Thirteen percent of 475 wives and 467 truckers reported ever having AI with their spouse. Of those who responded, 55 % of 40 wives and 47 % of 36 truckers never used condoms during AI. Of those who responded, 22 of 32 wives and 24 of 32 husbands felt that condoms were unnecessary during AI. Reporting ever having AI was associated with younger age and higher education of both husband and wife. AI reported by wives was associated with having sexual partner(s) other than husband (adjusted OR 8.8 [95 % CI 3.2-24.0]), correctly answering all HIV knowledge items (adjusted OR 4.9 [95 % CI 1.9-12.5]), husband's sexual debut occurring before marriage (adjusted OR 1.9 [95 % CI 1.0-3.5]), and husband's high HIV risk perception (adjusted OR 2.5 [95 % CI 1.2-5.4]). AI reported by truckers was associated with having sex with a male or transgender (adjusted OR 4.0 [95 % CI 1.2-13.3]). Reported prevalence of AI was high considering that in India anal sex is non-normative, heavily stigmatized and, criminal. Indian heterosexual mobile populations need to be informed about the greater risk of HIV infection consequent to unprotected AI.

Syphilis predicts HIV incidence among men and transgender women who have sex with men in a preexposure prophylaxis trial

Syphilis infection was associated with HIV incidence in an HIV-prevention trial that randomized participants to once-daily emtricitabine/tenofovir (FTC/TDF) vs placebo. FTC/TDF had no effect on the association between incident syphilis and HIV acquisition; syphilis infection did not decrease FTC/TDF efficacy.

Background. Syphilis infection may potentiate transmission of human immunodeficiency virus (HIV). We sought to determine the extent to which HIV acquisition was associated with syphilis infection within an HIV preexposure prophylaxis (PrEP) trial and whether emtricitabine/tenofovir (FTC/TDF) modified that association.

Methods. The Preexposure Prophylaxis Initiative (iPrEx) study randomly assigned 2499 HIV-seronegative men and transgender women who have sex with men (MSM) to receive oral daily FTC/TDF or placebo. Syphilis prevalence at screening and incidence during follow-up were measured. Hazard ratios for the effect of incident syphilis on HIV acquisition were calculated. The effect of FTC/TDF on incident syphilis and HIV acquisition was assessed.

Results. Of 2499 individuals, 360 (14.4%) had a positive rapid plasma reagin test at screening; 333 (92.5%) had a positive confirmatory test, which did not differ between the arms (FTC/TDF vs placebo, P = .81). The overall syphilis incidence during the trial was 7.3 cases per 100 person-years. There was no difference in syphilis incidence between the study arms (7.8 cases per 100 person-years for FTC/TDF vs 6.8 cases per 100 person-years for placebo, P = .304). HIV incidence varied by incident syphilis (2.8 cases per 100 person-years for no syphilis vs 8.0 cases per 100 person-years for incident syphilis), reflecting a hazard ratio of 2.6 (95% confidence interval, 1.6–4.4; P < .001). There was no evidence for interaction between randomization to the FTC/TDF arm and incident syphilis on HIV incidence.

Conclusions. In HIV-seronegative MSM, syphilis infection was associated with HIV acquisition in this PrEP trial; a syphilis diagnosis should prompt providers to offer PrEP unless otherwise contraindicated.

Effect of female genital schistosomiasis and anti-schistosomal treatment on monocytes, CD4+ T-cells and CCR5 expression in the female genital tract

Background

Schistosoma haematobium is a waterborne parasite that may cause female genital schistosomiasis (FGS), characterized by genital mucosal lesions. There is clinical and epidemiological evidence for a relationship between FGS and HIV. We investigated the impact of FGS on HIV target cell density and expression of the HIV co-receptor CCR5 in blood and cervical cytobrush samples. Furthermore we evaluated the effect of anti-schistosomal treatment on these cell populations.

Design

The study followed a case-control design with post treatment follow-up, nested in an on-going field study on FGS.

Methods

Blood and cervical cytobrush samples were collected from FGS negative and positive women for flow cytometry analyses. Urine samples were investigated for schistosome ova by microscopy and polymerase chain reaction (PCR).

Results

FGS was associated with a higher frequency of CD14⁺ cells (monocytes) in blood (11.5% in FGS+ vs. 2.2% in FGS-, p = 0.042). Frequencies of CD4⁺ cells expressing CCR5 were higher in blood samples from FGS+ than from FGS- women (4.7% vs. 1.5%, p = 0.018). The CD14⁺ cell population decreased significantly in both compartments after anti-schistosomal treatment (p = 0.043). Although the frequency of CD4+ cells did not change after treatment, frequencies of CCR5 expression by CD4+ cells decreased significantly in both compartments (from 3.4% to 0.5% in blood, p = 0.036; and from 42.4% to 5.6% in genital samples, p = 0.025).

Conclusions

The results support the hypothesis that FGS may increase the risk of HIV acquisition, not only through damage of the mucosal epithelial barrier, but also by affecting HIV target cell populations, and that anti-schistosomal treatment can modify this.

The slippery slope: lubricant use and rectal sexually transmitted infections: a newly identified risk

BACKGROUND

Use of lubricant products is extremely common during receptive anal intercourse (RAI) yet has not been assessed as a risk for acquisition of sexually transmitted infections (STIs).

METHODS

Between 2006 and 2008, a rectal health and behavior study was conducted in Baltimore and Los Angeles as part of the University of California, Los Angeles Microbicide Development Program (NIAID IPCP# #0606414). Participants completed questionnaires, and rectal swabs were tested for Neisseria gonorrhoeae and Chlamydia trachomatis with the Aptima Combo 2 assay, and blood was tested for syphilis (for RPR and TPHA with titer) and HIV. Of those reporting lubricant use and RAI, STI results were available for 380 participants. Univariate and multivariate regressions assessed associations of lubricant use in the past month during RAI with prevalent STIs.

RESULTS

Consistent lubricant use during RAI in the past month was reported by 36% (137/380) of participants. Consistent past month lubricant users had a higher prevalence of STI than inconsistent users (9.5% vs. 2.9%; P = 0.006). In a multivariable logistic regression model, testing positive for STI was associated with consistent use of lubricant during RAI in the past month (adjusted odds ratio: 2.98 95% confidence interval: 1.09, 8.15) after controlling for age, gender, study location, HIV status, and numbers of RAI partners in the past month.

CONCLUSIONS

Findings suggest some lubricant products may increase vulnerability to STIs. Because of wide use of lubricants and their potential as carrier vehicles for microbicides, further research is essential to clarify if lubricant use poses a public health risk.

Active recruitment strategy in disadvantaged immigrant populations improves the identification of human immunodeficiency but not of hepatitis B or C virus infections

BACKGROUND

Barriers to access medical screening and care may underestimate the number of diseased subjects among immigrant populations.

AIMS

To evaluate the prevalence of human immunodeficiency virus, hepatitis B virus and hepatitis C virus infections among immigrants recruited in a disadvantaged area.

METHODS

The study enrolled all subjects seen between 1999 and 2009 at an on-site health and family counselling centre for immigrants. During the first 6 years of the study a pro-active recruitment was performed using a mobile unit.

RESULTS

Overall 2681 subjects were enrolled (median age: 31 years; 52.8% males; 82.3% from Sub-Saharan Africa; 13.9% of the women were sex workers). A total of 206 subjects (7.6%) were hepatitis B surface antigen-positive, 84 (3.6%) were anti-hepatitis C virus-positive, 129 (5%) were anti-human immunodeficiency virus-positive, 84 (3.1%) were drug users, and 436 (16.3%) were alcohol abusers. The prevalence of hepatitis B surface antigen and anti-hepatitis C virus remained consistent throughout the study period, while the prevalence of human immunodeficiency virus significantly decreased. At multivariate analysis, hepatitis B virus infection was associated with male gender, hepatitis C virus infection with drug addiction, and human immunodeficiency virus infection was associated with female gender, drug addiction, and active recruitment.

CONCLUSIONS

An active recruitment strategy should be considered to reach disadvantaged populations at high risk of human immunodeficiency virus infection.

High transcript levels of vitamin D receptor are correlated with higher mRNA expression of human beta defensins and IL-10 in mucosa of HIV-1-exposed seronegative individuals

Vitamin D (VitD) is an endogenous immunomodulator that could protect from HIV-1 infection reducing immune activation and inducing the expression of anti-HIV-1 peptides. To establish a correlation between VitD and natural resistance to HIV-1 infection, a case-control study using blood and mucosa samples of 58 HIV-1-exposed but seronegative (HESN) individuals, 43 HIV-1 seropositives (SPs) and 59 non-exposed healthy controls (HCs) was carried out. The VitD concentration in plasma was determined by ELISA, and mRNA relative units (RU) of VDR, IL-10, TGF-β, TNF-α and IL-1β in peripheral blood mononuclear cells (PBMCs), oral and genital mucosa was quantified by qRT-PCR. mRNA levels of human beta-defensin (HBD) -2 and -3 were previously reported and used for correlations. Significantly higher levels of VitD were found in plasma as well as higher mRNA RU of VDR in PBMCs, and in genital mucosa from HESN compared to HCs. In addition, higher mRNA RU of TNF-α, IL-1β and IL-10, and lower mRNA RU of TGF-β were found in PBMC from HESNs compared to HCs. We also observed higher IL-10 mRNA RU in genital mucosa of HESNs compared to HCs, and the mRNA levels of TNF-α in oral and genital mucosa of SPs were higher compared to HESNs. Furthermore, positive correlations between VDR and IL-10 mRNA RU in PBMCs and genital mucosa of HESNs were found. Finally, HBD-2 and HBD-3 mRNA RU were positively correlated with VDR mRNA expression in oral mucosa from HESNs. These results suggest that high levels of VitD and its receptor are associated with natural resistance to HIV-1 infection. Up-regulation of the anti-inflammatory IL-10, and the induction of anti-HIV-1 defensins in mucosa might be part of the mechanisms involved in this association. However, further studies are required to define causal associations.

Association of genital human papillomavirus infection with HIV acquisition: a systematic review and meta-analysis

Objectives

To conduct a systematic review and a meta-analysis of epidemiological studies investigating the association of genital human papillomavirus (HPV) infection and HIV acquisition.

Design

Systematic review and meta-analysis.

Data Sources

Scientific databases and conference abstracts were systematically searched to identify all relevant studies published up to 31 January 2012. Search terms included ‘HIV’, ‘HPV’, ‘human papillomavirus’ and ‘papillomaviridae’ as keywords or text, in the title or abstract.

Methods

To be eligible for inclusion, a study had to be conducted among humans, report data on HIV incidence, and assess genital HPV infection. Summary ORs and 95% CIs were estimated from the extracted data using random-effect meta-analysis. Subgroup analyses were conducted for high-risk (HR) and low-risk (LR) HPV oncogenic risk groups. Between-study heterogeneity and publication bias were assessed.

Results

Of 2601 identified abstracts, six observational studies, comprising 6567 participants were retained for the systematic review and the meta-analysis. HIV acquisition was significantly associated with HPV infection (summary OR=1.96; 95% CI 1.55 to 2.49). HIV incident infection was significantly associated with HR-HPV in five of six studies and with LR-HPV in two out of five. The association was significant for HR-HPV (summary OR=1.92; 95% CI 1.49 to 2.46) and borderline for LR-HPV. No between-study heterogeneity was detected. There was a borderline indication of publication bias.

Conclusions

Further research is needed to elucidate the biological mechanisms involved, and assess the effect of HPV vaccination on HIV acquisition, using vaccines with broad coverage of HPV genotypes. Such research could have important public health implications for HIV prevention.

Small ruminant lentiviruses (SRLVs) break the species barrier to acquire new host range

Zoonotic events of simian immunodeficiency virus (SIV) from non-human primates to humans have generated the acquired immunodeficiency syndrome (AIDS), one of the most devastating infectious disease of the last century with more than 30 million people dead and about 40.3 million people currently infected worldwide. Human immunodeficiency virus (HIV-1 and HIV-2), the two major viruses that cause AIDS in humans are retroviruses of the lentivirus genus. The genus includes arthritis-encephalitis virus (CAEV) and Maedi-Visna virus (MVV), and a heterogeneous group of viruses known as small ruminant lentiviruses (SRLVs), affecting goat and sheep. Lentivirus genome integrates into the host DNA, causing persistent infection associated with a remarkable diversity during viral replication. Direct evidence of mixed infections with these two closely related SRLVs was found in both sheep and goats. The evidence of a genetic continuum with caprine and ovine field isolates demonstrates the absence of an efficient species barrier preventing cross-species transmission. In dual-infected animals, persistent infections with both CAEV and MVV have been described, and viral chimeras have been detected. This not only complicates animal trade between countries but favors the risk that highly pathogenic variants may emerge as has already been observed in the past in Iceland and, more recently, in outbreaks with virulent strains in Spain. SRLVs affecting wildlife have already been identified, demonstrating the existence of emergent viruses adapted to new hosts. Viruses adapted to wildlife ruminants may acquire novel biopathological properties which may endanger not only the new host species but also domestic ruminants and humans. SRLVs infecting sheep and goats follow a genomic evolution similar to that observed in HIV or in other lentiviruses. Lentivirus genetic diversity and host factors leading to the establishment of naturally occurring virulent versus avirulent infections, in addition to the emergence of new strains, challenge every aspect of SRLV control measures for providing efficient tools to prevent the transmission of diseases between wild ungulates and livestock.

Quantitative and qualitative differences in the T cell response to HIV in uninfected Ugandans exposed or unexposed to HIV-infected partners

HIV-exposed and yet persistently uninfected individuals have been an intriguing, repeated observation in multiple studies, but uncertainty persists on the significance and implications of this in devising protective strategies against HIV. We carried out a cross-sectional analysis of exposed uninfected partners in a Ugandan cohort of heterosexual serodiscordant couples (37.5% antiretroviral therapy naive) comparing their T cell responses to HIV peptides with those of unexposed uninfected individuals. We used an objective definition of exposure and inclusion criteria, blinded ex vivo and cultured gamma interferon (IFN-γ) enzyme-linked immunospot assays, and multiparameter flow cytometry and intracellular cytokine staining to investigate the features of the HIV-specific response in exposed versus unexposed uninfected individuals. A response rate to HIV was detectable in unexposed uninfected (5.7%, 95% confidence interval [CI] = 3.3 to 8.1%) and, at a significantly higher level (12.5%, 95% CI = 9.7 to 15.4%, P = 0.0004), in exposed uninfected individuals. The response rate to Gag was significantly higher in exposed uninfected (10/50 [20.%]) compared to unexposed uninfected (1/35 [2.9%]) individuals (P = 0.0004). The magnitude of responses was also greater in exposed uninfected individuals but not statistically significant. The average number of peptide pools recognized was significantly higher in exposed uninfected subjects than in unexposed uninfected subjects (1.21 versus 0.47; P = 0.0106). The proportion of multifunctional responses was different in the two groups, with a higher proportion of single cytokine responses, mostly IFN-γ, in unexposed uninfected individuals compared to exposed uninfected individuals. Our findings demonstrate both quantitative and qualitative differences in T cell reactivity to HIV between HESN (HIV exposed seronegative) and HUSN (HIV unexposed seronegative) subject groups but do not discriminate as to whether they represent markers of exposure or of protection against HIV infection.

Frequency of sexual activity with most recent male partner among young, Internet-using men who have sex with men in the United States

Sex frequency, defined here as the number of oral or anal sex acts with the most recent partner in the past year, is a potential driver of risk for sexually transmitted infections. However, few data on sex frequency have been reported for men who have sex with men (MSM). Data from an Internet survey of MSM were used to describe sex frequency with most recent main and casual male partners and to estimate factors associated with higher sex frequency. Among 5,193 MSM, higher sex frequency was associated with younger age, shorter relationship duration, and reporting a main (vs. casual) partner; and lower sex frequency with male partners was associated with heterosexual or bisexual (vs. homosexual) identity or Black race (vs. non-Hispanic White). Secondary analyses of estimates of sex frequency from 2 publicly available nationally representative datasets comprised of primarily heterosexual survey respondents (the 2008 General Social Survey and the 1992 National Health and Social Life Survey) were performed. Sex frequency among MSM respondents was similar to that reported by heterosexuals.

The physiology of sexual violence, genito-anal injury and HIV: opportunities for improving risk estimation

Increased understanding about the relative contribution of genito-anal injury to HIV transmission may improve epidemic model estimates of the distribution of risk among and across different subpopulations. Better understanding about the distribution of HIV among subpopulations that are at highest risk of sexual violence can also improve the design and prioritization of combination prevention interventions that are most likely to reduce the risk of sexual violence and its potential contribution to HIV transmission. The effective incorporation of physiological and social variables into epidemic modelling will likely require new research approaches that can help communicate the level of risk associated with different types of 'heterosexual' transmission. Reference models that reflect the potential impact of sexual violence and genital injury can help direct attention toward key variables and uncertainties. For further research that clarifies these relationships will require multidisciplinary collaboration among groups with expertise in epidemiology, social science, public health, and clinical and basic science.

Biology as population dynamics: heuristics for transmission risk

Population-type models, accounting for phenomena such as population lifetimes, mixing patterns, recruitment patterns, genetic evolution and environmental conditions, can be usefully applied to the biology of HIV infection and viral replication. A simple dynamic model can explore the effect of a vaccine-like stimulus on the mortality and infectiousness, which formally looks like fertility, of invading virions; the mortality of freshly infected cells; and the availability of target cells, all of which impact on the probability of infection. Variations on this model could capture the importance of the timing and duration of different key events in viral transmission, and hence be applied to questions of mucosal immunology. The dynamical insights and assumptions of such models are compatible with the continuum of between- and within-individual risks in sexual violence and may be helpful in making sense of the sparse data available on the association between HIV transmission and sexual violence.

Greentree white paper: sexual violence, genitoanal injury, and HIV: priorities for research, policy, and practice

The links between sexual violence, genitoanal injury, and HIV are understudied but potentially significant for understanding the epidemic's disproportionate impacts on young women and girls, particularly in sub-Saharan Africa, other hyperendemic areas, and conflict-affected regions. A Scientific Research Planning Meeting was convened by the Social Science Research Council at the Greentree Foundation in New York, March 19-20, 2012, bringing together an interdisciplinary group of researchers, clinicians, and policy makers to identify knowledge needs and gaps in three key areas: (1) the role of genitoanal injury on HIV transmission, acquisition, and pathogenesis; (2) the influence of sex and age-related anatomic characteristics on HIV transmission, acquisition, and pathogenesis; and (3) the role of heterosexual anal intercourse in HIV transmission. This article reflects the consensus that emerged from the Greentree Meeting regarding priority scientific research questions in these three areas, associated data collection and measurement challenges and opportunities, and implications for policy and practice.

Comparison of sexual behavior and HIV risk between two HIV-1 serodiscordant couple cohorts: the CHAVI 002 study

BACKGROUND

The CHAVI002 study was designed to characterize immune responses, particularly HIV-specific T-cell responses, amongst 2 cohorts of HIV-exposed seronegative (HESN) individuals. The absence of a clear definition of HESNs has impaired comparison of research within and between such cohorts. This report describes two distinct HESN cohorts and attempts to quantify HIV exposure using a 'HIV risk index' (RI) model.

METHODS

HIV serodiscordant couples (UK; 24, Uganda; 72) and HIV unexposed seronegative (HUSN) controls (UK; 14, Uganda; 26 couples, 3 individuals) completed sexual behavior questionnaires every 3 months over a 9 month period. The two cohorts were heterogeneous, with most HESNs in the UK men who have sex with men (MSM), while all HESNs in Uganda were in heterosexual relationships. Concordance of responses between partners was determined. Each participant's sexual behavior score (SBS) was estimated based on the number and type of unprotected sex acts carried out in defined time periods. Independent HIV acquisition risk factors (partner plasma viral load, STIs, male circumcision, pregnancy) were integrated with the SBS, generating a RI for each HESN.

RESULTS

96 HIV serodiscordant couples completed 929 SBQs. SBSs remained relatively stable amongst the UK cohort, whilst decreasing from Visit 1 to 2 in the Ugandan cohort. Compared to the Ugandan cohort, SBSs and RIs in the UK cohort were lower at visit 1, and generally higher at later visits. Differences between the cohorts, with lower rates of ART use in Uganda and higher risk per-act sex in the UK, had major impacts on the SBSs and RIs of each cohort. There was one HIV transmission event in the UK cohort.

CONCLUSIONS

Employment of a risk quantification model facilitated quantification and comparison of HIV acquisition risk across two disparate HIV serodiscordant couple cohorts.

Antiretroviral therapy: a key component of a comprehensive HIV prevention strategy

Transmission of HIV is critically dependent on the level of HIV viral load within blood and genital secretions. Antiretroviral therapy results in sustained reductions in viral load to undetectable levels. Thus, antiretroviral therapy has long been postulated as a potential means to curb HIV transmission. Observational data have now confirmed that antiretroviral therapy is associated with a decrease in transmission among heterosexual serodiscordant couples, injection-drug users, and in population-based studies. Mathematical models suggest that further expansion of antiretroviral coverage within current guidelines can play a major role in controlling the spread of HIV. Concerns regarding the potential for transmission during acute HIV infection, behavioral disinhibition, and resistance to overcome the impact of treatment on prevention have not materialized to date. The Joint United Nations AIDS (UNAIDS) program has called for the inclusion of antiretroviral treatment as a key pillar in the global strategy to control the spread of HIV infection.

A clinic-based motivational intervention improves condom use among subgroups of youth living with HIV

PURPOSE

More than 50% of youth living with HIV (YLH) have unprotected sex. In previous studies, we reported effects of a motivational interviewing-based multirisk reduction intervention, "Healthy Choices" in improving motivation, depression, and viral load in YLH. In this study, we report the effect of the intervention on increasing condom use.

METHODS

Six waves of longitudinal data (n = 142) across a period from baseline through 15 months postintervention were analyzed. The developmental trajectory modeling method was used for program effect evaluation.

RESULTS

The three groups detected with distinct sexual risks were: Persistent low sexual risk (PLSR), delayed high sexual risk, and high and growing sexual risk with regard to levels and time trajectories of condom use throughout the trial. Receiving Healthy Choices increased the likelihood to be in the PLSR group (63% vs. 32%, p < .01) and reduced the likelihood to be in the delayed high sexual risk group (16% vs. 50%, p < .05). Receiving the intervention was also associated with progressive reductions in no-condom sex for PLSR youth (adjusted β = -.325, p < .01) and high and growing sexual risk youth (adjusted β = -.364, p < .01).

CONCLUSION

The motivational interviewing-based program Healthy Choices, when delivered in clinic settings, can prevent unprotected sex in subgroups of YLH, although more intensive interventions may be needed to change risk trajectories among those at highest risk of transmitting the AIDS virus. Developmental trajectory analysis provides an alternative approach to evaluate program effects for study samples that contain distinct subgroups.

Patterns of HIV testing at a London teaching hospital between 2004 and 2007

To observe trends in testing for HIV between 2004 and 2007 in a London hospital and to observe the seroprevalence of HIV within subgroups. Tests were grouped according to source and reason for testing; 58,720 tests were considered (HIV-1 seroprevalence = 0.9%). The majority (75.4%) of tests were performed as part of routine and opt-out protocols including antenatal and genitourinary screening. Among people specifically seeking HIV testing, the HIV seroprevalence was 3.5%. Medical specialties performed fewer tests but a high HIV seroprevalence was observed, including infectious disease (seroprevalence 4.4%) and other medical specialties (seroprevalence 3.4%). A small number of specialties performed few HIV tests. HIV testing was cost-effective in virtually all settings. This study suggests that more HIV tests could be performed, for example, in acute medicine, and training might increase the number of tests offered in some settings. The most effective way of increasing testing appears to be opt-out testing.

The relative contribution of viral and bacterial sexually transmitted infections on HIV acquisition in southern African women in the Methods for Improving Reproductive Health in Africa study

We assess the relative contribution of viral and bacterial sexually transmitted infections (STIs) on HIV acquisition among southern African women in a nested case-control study within the Methods for Improving Reproductive Health in Africa (MIRA) trial. Cases were women with incident HIV infection; controls were HIV-uninfected at the time of case seroconversion selected in a 1 to 3 case to control ratio (risk-set sampling), matched on study site and time of follow-up. Conditional logistic regression models were used to calculate adjusted odds ratios (AORs) and population-attributable fractions (PAF). Among 4948 enrolled women, we analysed 309 cases and 927 controls. The overall HIV incidence rate was 4.0 per 100 women-years. The incidence of HIV infection was markedly higher in women who had prevalent Herpes simplex virus type 2 (HSV-2) (AOR: 2.14; 95% confidence interval [CI]: 1.55–2.96), incident HSV-2 (AOR: 4.43; 95% CI: 1.77–11.05) and incident Neisseria gonorrhoeae (AOR: 6.92; 95% CI: 3.01–15.90). The adjusted PAF of HIV incidence for prevalent HSV-2 was 29.0% (95% CI: 16.8–39.3), for incident HSV-2 2.1% (95% CI: 0.6–3.6) and for incident N. gonorrhoeae 4.1% (95% CI: 2.5–5.8). Women's greatest risk factors for HIV acquisition were incident bacterial and viral STIs. Women-centred interventions aimed at decreasing HIV incidence in young African women need to address these common co-morbid conditions.

Differences in HIV-specific T cell responses between HIV-exposed and -unexposed HIV-seronegative individuals

HIV-1-specific T lymphocyte responses in individuals exposed to HIV-1 but who remain persistently seronegative (HESNs) have been reported in some but not all previous studies. This study was designed to resolve unequivocally the question of whether HESNs make HIV-1-specific T cell responses. We performed a blind investigation to measure HIV-1-specific T cell responses in both HIV-1-serodiscordant couples and HIV-1-unexposed seronegative controls (HUSNs). We found low-frequency HIV-1-specific T cells in both HESNs and HUSNs but show that the response rates were higher over time in the former (P = 0.01). Furthermore, the magnitudes of the HIV-1-specific T cell responses were significantly higher among responding HESNs than among HUSNs over time (P = 0.002). In both groups, responses were mediated by CD4 T cells. The responses were mapped to single peptides, which often corresponded to epitopes restricted by multiple HLA-DR types that have previously been detected in HIV-1-infected patients. HIV-1-specific T cell responses in HUSNs and some HESNs likely represent cross-reactivity to self or foreign non-HIV-1 antigens. The significantly greater T cell responses in HESNs, including in two who were homozygous for CCR5Δ32, demonstrates that HIV-1-specific T cell responses can be induced or augmented by exposure to HIV-1 without infection.