Heterosexual transmission of human immunodeficiency virus (HIV) in northern California: results from a ten-year study

Urban Sexual Health Clinic Patients With "Undetermined Risk" for HIV Are Less Likely to Receive Preexposure Prophylaxis

BACKGROUND

New diagnoses of HIV increasingly occur among people who fall outside traditional transmission risk categories. This group remains poorly defined, and HIV prevention efforts for this group lag behind efforts for patients in other risk groups.

METHODS

We conducted a retrospective review of patient visits at sexual health clinics in Boston, MA, over a 14-month period. Patients were classified into Centers for Disease Control and Prevention-defined HIV transmission risk categories. We compared frequencies of sexually transmitted infections (STIs), HIV, preexposure prophylaxis (PrEP) indications, and PrEP prescriptions. Predictors of HIV or STI among patients in the undetermined risk category were assessed with logistic regression.

RESULTS

There were 4723 clinic visits during the study period. Patients in the undetermined risk group constituted the largest proportion (55.8%), followed by men who have sex with men (MSM; 42.7%). The proportion of visits by patients in the undetermined risk group with an indication for PrEP was low (28.0%) compared with MSM (91.3%) and MSM who also inject drugs (93.8%); however, the absolute number was high (737). Among patients with an indication for PrEP, those in the undetermined risk group were least likely to receive a prescription. Behavioral risk factors were poorly predictive of STI or HIV among patients in the undetermined risk group.

CONCLUSIONS

Patients with undetermined risk for HIV constituted a large proportion of clinic visits and had a large volume of sexual health needs but rarely received PrEP when indicated. To end the HIV epidemic in the United States, prevention efforts must include people who fall outside traditional risk categories.

Early Colorectal Responses to HIV-1 and Modulation by Antiretroviral Drugs

Innate responses during acute HIV infection correlate with disease progression and pathogenesis. However, limited information is available about the events occurring during the first hours of infection in the mucosal sites of transmission. With an ex vivo HIV-1 challenge model of human colorectal tissue we assessed the mucosal responses induced by R5- and X4-tropic HIV-1 isolates in the first 24 h of exposure. Microscopy studies demonstrated virus penetration of up to 39 μm into the lamina propia within 6 h of inoculation. A rapid, 6 h post-challenge, increase in the level of secretion of inflammatory cytokines, chemokines, interferon- γ (IFN-γ), and granulocyte-macrophage colony-stimulating factor (GM-CSF) was observed following exposure to R5- or X4-tropic isolates. This profile persisted at the later time point measured of 24 h. However, exposure to the X4-tropic isolate tested induced greater changes at the proteomic and transcriptomic levels than the R5-tropic. The X4-isolate induced greater levels of CCR5 ligands (RANTES, MIP-1α and MIP-1β) secretion than R5-HIV-1. Potential drugs candidates for colorectal microbicides, including entry, fusion or reverse transcriptase inhibitors demonstrated differential capacity to modulate these responses. Our findings indicate that in colorectal tissue, inflammatory responses and a Th1 cytokine profile are induced in the first 24 h following viral exposure.

Transmission routes of human immunodeficiency virus and affecting factors

Acquired immunodeficiency syndrome (AIDS) was first reported more than 30 years ago among homosexuals in the United States. The epidemiology of this disease indicates that there are three modes of transmission: Blood, mother-to-child, and sexual contact transmission. The pathogen of AIDS is human immunodeficiency virus (HIV), primarily HIV-1. HIV-1 could not break through the structurally and functionally integral skin, and primarily invades the human body through the mucosa irrespective of their integrity. Therefore, the mucosae are the natural transmission routes for HIV-1. The mucosae involved in HIV-1 transmission include the mucosae of the gastrointestinal tract and the urogenital tract. The risks of HIV-1 transmission vary significantly between mucosal sites and individuals, and are associated with mucosal integrity, abundance of target cells, immune status of the host, commensal microbes, and host genetic background. Many factors are closely related to the barrier function of the mucosa, and studies on their roles in HIV-1 invasion could promote the prevention and control of mucosal transmission of HIV-1.

Ten-year survival with analysis of gender difference, risk factors, and causes of death during 13 years of public antiretroviral therapy in rural Kenya

Evidence for why antiretroviral therapy (ART) outcomes differ by gender in developing countries has been inconclusive. In this first study to assess 10-year survival on ART in Kenya, our objective was to compare gender differences in survival for those who began ART as adults and as children. Kakamega County Referral Hospital (KCRH) is a tertiary rural hospital that has provided public ART to Kenyans since 2004. All patients enrolled in ART at KCRH who died between July 2004 and March 2017 and a sample of living patients were included in a survival analysis that bootstrapped sampled data. Case-cohort regressions identified adjusted hazard ratios. In total, 1360 patients were included in the study. Ten-year survival was 77% (95% confidence band [CB] 73-81%), significantly different for men (65%; 95% CB: 45-74%) and women (83%; 95% CB: 78-86%) who began therapy as adults. Ten-year survival was intermediate with no significant gender difference (76%; 95% CB: 69-81%) for patients who began therapy as children. Hazard of death was increased for men (hazard ratio [HR] 1.56; 95% confidence interval [CI] 1.13-2.17), infants (HR 2.87; 95% CI 1.44-5.74), patients with consistently poor clinic attendance (HR 3.94; 95% CI 3.19-4.86), and divorced patients (HR 2.25; 95% CI 1.19-4.25). Tuberculosis, diarrheal illnesses, human immunodeficiency virus (HIV) wasting syndrome, and malaria were leading causes of death. Survival was significantly lower for men than for women in all time periods, but only for patients who began therapy as adults, indicating against biological etiologies for the gender mortality difference.

Decision making over condom use during menses to avert sexually transmissible infections

Background The aim of this study was to test the hypothesis that receptive partners in penile-vaginal intercourse (PVI) who exercise independent decision making over condom use during menses do so to avert sexually transmissible infection (STI) transmission or acquisition.

METHODS

Data were collected through a partnership with Clue, the industry-leading female health app. A brief web-based questionnaire was developed, translated into 10 languages, and made accessible via a URL link sent to Clue users and posted on social media. Inclusion criteria were: age ≥14 years, not being currently pregnant and engaging in PVI and condom use during menses in the past 3 months. The analytical subsample comprised 12889 respondents residing in 146 countries.

RESULTS

Twenty per cent indicated independent decision making about condom use during menses. Independent decision making was associated with lower odds of reporting that condoms were used for contraception (adjusted odds ratio (aOR) 0.65; 99% confidence interval (CI) 0.57-0.73) and higher odds that they were used for the prevention of STIs (aOR 1.44; 99% CI 1.28-1.61). A third significant finding pertained to always using condoms during menses; this was less likely among those indicating independent (female only) decision making (aOR 0.69; 99% CI 0.62-0.78). Non-significant associations with another two outcomes were found: protecting the partner against menstrual blood and protecting themselves against semen.

CONCLUSIONS

Findings from people in 146 countries strongly support the hypothesis that those exercising independent decision making over condom use during menses do so to avert STI transmission or acquisition. That only one-fifth of this global sample reported this type of independent decision making suggests that empowerment-oriented (structural-level) interventions may be advantageous for individuals who are the receptive partner in PVI that occurs during menses.

Developing a dynamic HIV transmission model for 6 U.S. cities: An evidence synthesis

BACKGROUND

Dynamic HIV transmission models can provide evidence-based guidance on optimal combination implementation strategies to treat and prevent HIV/AIDS. However, these models can be extremely data intensive, and the availability of good-quality data characterizing regional microepidemics varies substantially within and across countries. We aim to provide a comprehensive and transparent description of an evidence synthesis process and reporting framework employed to populate and calibrate a dynamic, compartmental HIV transmission model for six US cities.

METHODS

We executed a mixed-method evidence synthesis strategy to populate model parameters in six categories: (i) initial HIV-negative and HIV-infected populations; (ii) parameters used to calculate the probability of HIV transmission; (iii) screening, diagnosis, treatment and HIV disease progression; (iv) HIV prevention programs; (v) the costs of medical care; and (vi) health utility weights for each stage of HIV disease progression. We identified parameters that required city-specific data and stratification by gender, risk group and race/ethnicity a priori and sought out databases for primary analysis to augment our evidence synthesis. We ranked the quality of each parameter using context- and domain-specific criteria and verified sources and assumptions with our scientific advisory committee.

FINDINGS

To inform the 1,667 parameters needed to populate our model, we synthesized evidence from 59 peer-reviewed publications and 24 public health and surveillance reports and executed primary analyses using 11 data sets. Of these 1,667 parameters, 1,517 (91%) were city-specific and 150 (9%) were common for all cities. Notably, 1,074 (64%), 201 (12%) and 312 (19%) parameters corresponded to categories (i), (ii) and (iii), respectively. Parameters ranked as best- to moderate-quality evidence comprised 39% of the common parameters and ranged from 56%-60% across cities for the city-specific parameters. We identified variation in parameter values across cities as well as within cities across risk and race/ethnic groups.

CONCLUSIONS

Better integration of modelling in decision making can be achieved by systematically reporting on the evidence synthesis process that is used to populate models, and by explicitly assessing the quality of data entered into the model. The effective communication of this process can help prioritize data collection of the most informative components of local HIV prevention and care services in order to reduce decision uncertainty and strengthen model conclusions.

[ADS-J1 antagonizes semen-derived enhancer of virus infection-mediated enhancement of transmitted founder HIV-1 and its matched chronic control strain infection]

OBJECTIVE

To investigate the effect of semen-derived enhancer of virus infection (SEVI) on the infection of transmitted/founder (TF) HIV-1 and its matched chronic control (CC) viruses and the antagonism of ADS-J1 on SEVI-mediated enhancement of TF and CC virus infection in vitro.

METHODS

PAP_248-286 self-assembling into SEVI amyloid fibrils was validated by ThT assay. We generated the virus stocks of TF and CC virus pair. TZM-bl cells were infected with the mixture of SEVI and TF or CC viruses for 72 h. Luciferase activity was used to observe the enhancement of SEVI. SEVI was treated with different concentrations of ADS-J1 and incubated with TF or CC viruses. TZM-bl cells were then infected with the mixture and luciferase activity was detected 72 h after infection to analyze the antagonism of ADS-J1 on the enhancing effect of SEVI. ADS-J1 was also incubated with TF and CC viruses directly and TZM-bl cells were infected for 72 h to evaluate the antiviral effect using luciferase assay. SEVI was treated with ADS-J1 and Zeta potential was determined to explore the antagonistic mechanism of ADS-J1.

RESULTS

ThT assay showed that PAP_248-286 was capable of self-assembly into SEVI amyloid fibrils. SEVI significantly accelerated TF and CC viruses infection (P<0.05), and ADS-J1 not only significantly antagonized the enhancement of SEVI (P<0.05) but also directly inhibited the infection of TF and CC viruses (P<0.05). ADS-J1 neutralized the positive charge of SEVI in a dose-dependent manner.

CONCLUSIONS

SEVI promotes the infection of TF and CC strains, and ADS-J1 antagonizes SEVI-mediated enhancement of TF and CC viruses by neutralizing the positive charge of SEVI.

Acceptability of a Tenofovir Disoproxil Fumarate Vaginal Ring for HIV Prevention Among Women in New York City

Vaginal rings for pre-exposure prophylaxis are a female-initiated HIV prevention method that does not require daily or coitally-dependent dosing. As part of a randomized placebo-controlled trial of a tenofovir disoproxil fumarate intravaginal ring, we assessed product acceptability through in-depth interviews with 18 women during and after 14 days of continuous use. Women reported that the ring was comfortable with few side effects, regardless of experimental arm. However, interest in future use by this cohort was modest for several reasons including: low self-perceived HIV risk; concern that use implied promiscuity; potential for interference with relationship formation and trust; concern for interference with menstruation and cleanliness; and worries about partners' acceptability and sexual pleasure. Potential issues were raised with duration of use prior to ring exchange. Future studies should continue to identify and address individual and relationship factors that influence acceptability, early in the product development process.

Projecting the impact of anal intercourse on HIV transmission among heterosexuals in high HIV prevalence settings

Whereas penile vaginal intercourse (VI) is thought to be the dominant mode of HIV transmission in sub-Saharan Africa, cross-sectional studies in the region indicate the preponderance of heterosexual anal intercourse (AI) among high activity groups. A dynamic, heterosexual core group model with risk of infection through both vaginal and anal pathways is formulated and comprehensively analysed. The model is coupled to a general population model and fitted to HIV prevalence data for Zimbabwe in order to explore the parameter space related to heterosexual AI. The model fit supports a core group size ranging between 5-20% and exposure risk to AI in excess of 50%. The control effort quantified by the reproductive number (R_A) at commencement of the epidemic corresponds to R₀=4.40. With the contribution of heterosexual AI to Zimbabwe's (and that of the sub-Saharan African region) epidemic unknown, the study apportioned infections between the two infection pathways. New infections due to VI ranged from 2-4.5% and 0.5-2.7% from heterosexual AI. The study estimates infection probabilities ranging from 0.15 to 0.35 for both receptive and infective AI. By quantifying the incidence due to VI and AI risks, we put emphasis on the necessity for targeted interventions. To project the potential impact of heterosexual AI in high HIV prevalence settings, we raised the core group size to 20% in the year 2010 coinciding with reported heterosexual AI prevalence outside of Africa and allowed the proportion of infection risk associated with AI to vary. Prevalence and incidence projections were made up to the year 2020 starting from a baseline value of zero exposure to AI transmission risk per sex act, progressively increasing exposure to 50% and 70% respectively. A 50% exposure to AI would result in HIV prevalence scaling up by 23% from the baseline values in year 2020. Increasing exposure to 70% was projected to increase HIV prevalence by 38% in year 2020. The HIV infection risks associated with AI are recognised and inform HIV policy for men who have sex with men, yet the same risks are ignored in HIV intervention programmes for heterosexuals. This study highlights the potential danger of increasing prevalence of heterosexual AI in settings with high HIV prevalence. Evolving and globally cross pollinating sexual behaviors compel for dovetailing HIV policy making with sexology.

HIV/STD: the women to blame? Knowledge and attitudes among STD clinic attendees in the second decade of HIV/AIDS

We aimed to determine the knowledge and attitudes towards HIV/STDs among women attending an STD clinic by interviewing 520 randomly selected women. Nearly all had heard of HIV/AIDS/STDs, with posters, pamphlets and the radio being the main source of their information. The years of schooling was the only predictive factor of knowing a preventive measure of HIV. Two-thirds thought they were at risk of contracting HIV from their regular partner. Knowledge of the sexual habits of their male partners was low with 260 (50%) of the women distrusting their partner. Only 52 (10%) of respondents admitted to sex in exchange for gifts or money. In the event of a positive HIV test result, the perceived partner response would be to blame the woman for introducing the infection into the relationship. After a positive HIV test result, only 3.5% would resort to using condoms while another 3.7% would try to pass on the disease to other people. The quality of their knowledge of the transmission of HIV was low in spite of the fact that most respondents have heard of HIV/AIDS/STDs. Violence against women was expected in relation to a positive test result. There is a need for better educative effort on the modes of transmission and prevention of HIV, also in ‘low risk’ populations.

Heterosexual Anal Sex Among Men and Women in Substance Abuse Treatment: Secondary Analysis of Two Gender-Specific HIV-Prevention Trials

Receptive anal sex has high human immunodeficiency virus (HIV) transmission risk, and heterosexual substance-abusing individuals report higher anal sex rates compared to their counterparts in the general population. This secondary analysis evaluated the effectiveness of two gender-specific, evidence-based HIV-prevention interventions (Real Men Are Safe, or REMAS, for men; Safer Sex Skill Building, or SSSB, for women) against an HIV education (HIV-Ed) control condition on decreasing unprotected heterosexual anal sex (HAS) among substance abuse treatment-seeking men (n = 171) and women (n = 105). Two variables, engagement in any HAS and engagement in unprotected HAS, were assessed at baseline and three months postintervention. Compared to the control group, women in the gender-specific intervention did not differ on rates of any HAS at follow-up but significantly decreased their rates of unprotected HAS. Men in both the gender-specific and the control interventions reported less HAS and unprotected HAS at three-month follow-up compared to baseline, with no treatment condition effect. The mechanism of action for SSSB compared to REMAS in decreasing unprotected HAS is unclear. More attention to HAS in HIV-prevention interventions for heterosexual men and women in substance abuse treatment is warranted.

Cost-Effectiveness of the 'One4All' HIV Linkage Intervention in Guangxi Zhuang Autonomous Region, China

BACKGROUND

In Guangxi Zhuang Autonomous Region, China, an estimated 80% of newly-identified antiretroviral therapy (ART)-eligible patients are not engaged in ART. Delayed ART uptake ultimately translates into high rates of HIV morbidity, mortality, and transmission. To enhance HIV testing receipt and subsequent treatment uptake in Guangxi, the Chinese Center for Disease Control and Prevention (CDC) executed a cluster-randomized trial to assess the effectiveness and cost-effectiveness of a streamlined HIV testing algorithm (the One4All intervention) in 12 county-level hospitals.

OBJECTIVE

To determine the incremental cost-effectiveness of the One4All intervention delivered at county hospitals in Guangxi, China, compared to the current standard of care (SOC).

PERSPECTIVE

Health System.

TIME HORIZON

1-, 5-and 25-years.

METHODS

We adapted a dynamic, compartmental HIV transmission model to simulate HIV transmission and progression in Guangxi, China and identify the economic impact and health benefits of implementing the One4All intervention in all Guangxi hospitals. The One4All intervention algorithm entails rapid point-of-care HIV screening, CD4 and viral load testing of individuals presenting for HIV screening, with same-day results and linkage to counselling. We populated the model with data from the One4All trial (CTN-0056), China CDC HIV registry and published reports. Model outcomes were HIV incidence, mortality, costs, quality-adjusted life years (QALYs), and the incremental cost-effectiveness ratio (ICER) of the One4All intervention compared to SOC.

RESULTS

The One4All testing intervention was more costly than SOC (CNY 2,182 vs. CNY 846), but facilitated earlier ART access, resulting in delayed disease progression and mortality. Over a 25-year time horizon, we estimated that introducing One4All in Guangxi would result in 802 averted HIV cases and 1629 averted deaths at an ICER of CNY 11,678 per QALY gained. Sensitivity analysis revealed that One4All remained cost-effective at even minimal levels of effectiveness. Results were robust to changes to a range of parameters characterizing the HIV epidemic over time.

CONCLUSIONS

The One4All HIV testing strategy was highly cost-effective by WHO standards, and should be prioritized for widespread implementation in Guangxi, China. Integrating the intervention within a broader combination prevention strategy would enhance the public health response to HIV/AIDS in Guangxi.

Opportunities and Gaps in Primary Care Preventative Health Services for Transgender Patients: A Systemic Review

Purpose: Transgender people face barriers to accessing healthcare, resulting in population-level disparities in health outcomes. Little research is available to better understand the receipt of primary healthcare among transgender patients or how the rate of receipt of preventive care may differ among transgender populations. Methods: The medical literature regarding U.S. adult transgender primary healthcare was reviewed using a keyword search strategy: transgender OR transsexual OR transvestite OR gender nonconforming for articles published between January 1, 2001 and June 15, 2015. Studies addressing the following topics as assessed by the Behavioral Risk Factor Surveillance System were extracted for qualitative review: colorectal cancer screenings, mammography or chest/breast tissue examinations, cholesterol and blood pressure screenings, tobacco use and smoking cessation, cervical cancer or human papillomavirus (HPV) screenings, human immunodeficiency virus (HIV), annual flu shot, and insurance coverage. Results: The search identified 1304 eligible records, of which 41 discussed transgender primary or preventive care. The majority of studies discussed HIV rates or risk behaviors, while fewer articles addressed pelvic examinations, tobacco use, insurance coverage, and cholesterol screenings. No studies addressed mammography or chest/breast tissue examinations, colorectal screenings, or flu shots. Conclusions: Findings from articles addressing five topics are discussed: HIV, cholesterol screenings, tobacco use, pelvic health, and insurance coverage. Gaps in the extant literature, including the lack of studies of nonbinary people, transgender men of color, and transgender people living outside of large coastal urban centers, are discussed. This review, coincident with other health disparity findings, suggests an urgent need for research that addresses the primary care needs of all transgender and gender nonconforming people.

The Primacy of Gender in STD and HIV Prevention Programmes

Intervention projects aimed at preventing STD and HIV generally tend to target women sex workers and through them their clients. This approach sees women sex workers as agents of change, with the attendant burden, but has failed to recognise gender issues surrounding sexual health, particularly power relations existing in society. While gender justice is a recognised legitimate concern, the discourse has excluded sex workers from its purview making them the moral 'other'. Sexual health projects implemented currently in different parts of Kerala are not sensitive to gender issues because they mistakenly assume that sex workers are autonomous subjects. In the sexual health project for female sex workers implemented in the Kottayam municipal area some gender issues were tackled with modest success. This paper makes a strong plea for more gender sensitivity in sexual health projects and for men to take their fair share of responsibility for HIV transmission.

Pathways That Affect Wives' HIV Risk Among Serodiscordant Couples in India: Results From the Positive Jeevan Saathi Study

This study examined factors that mitigate or heighten HIV risk among HIV-negative wives in serodiscordant relationships in Gujarat, India. Grounded theory was used to analyze 46 interviews (23 couples) where husbands were HIV-positive and wives were HIV-negative. A conceptual framework emerged from analysis from which we identified five pathways and four key behaviors: (a) safer sex, (b) no sex, (c) coercive sex, and (d) unprotected sex. Most couples either practiced safe sex or abstained from sex. Factors such as wives' assertiveness, a wife's fear of acquiring HIV, mutual understanding, positive sex communication, and a husband's desire to protect wife influenced safe sex/sexual abstinence. Factors such as desire for children, a husband's alcohol use, and intimate partner violence influenced coercive and unprotected sex. Counseling topics on sex communication, verbal and non-verbal safer sex strategies, as well as addressing intimate partner violence and alcohol use may be important in preventing risk to HIV-negative wives.

Disciplining Bodies, Desires and Subjectivities: Sexuality and HIV-Positive Women

Very little is known about the sexuality of women who are living with HIV, outside the context of risk prevention and education. Available research in the first-world context shows that, although most women continue to be sexually active following diagnosis, decreased sexual functioning is very common and more prevalent than among HIV-positive men. The present multi-site Canadian study is concerned with the ways in which women’s sexuality is transformed by the experience of living with HIV. Semi-structured interviews with 20 women were analysed using thematic decomposition, an analytic technique that combines discursive approaches with thematic analysis. The women in this study construct HIV as inhibiting in relation to sexuality. A predominant discourse of disciplining bodies, desires and subjectivities emerges, which centers on the restrictions imposed by an HIV-positive diagnosis. The following discursive constructions, in particular, emerge from the women’s accounts: diminished spontaneity, foreclosed (provisional) sexual freedom, foreclosed power, foreclosed flirtation, inciting violence, (un)natural sex, responsibility imperatives, muted/mutated sexuality, and diminished intimacy. The women’s predominant positioning within AIDS discourses as conduits of transmission, the relative neglect of women’s psychological and sexual health concerns in both research and public health agendas, and women’s relatively anomalous standing in AIDS communities imposes limits on bodies, lives, and subjectivities. These are reflected in these women’s accounts, wherein a focus on protecting others frequently impedes access to fulfilling (and safe) sexual and emotional relationships.

A Systematic Review of the Inclusion (or Exclusion) of Women in HIV Research: From Clinical Studies of Antiretrovirals and Vaccines to Cure Strategies

INTRODUCTION

The effect of clinical interventions can differ because of sex/gender. Studies have shown that women are often under-represented in medical research. The aim of this systematic literature review was to characterize women's participation in HIV clinical studies of antiretroviral drugs (ARV), prophylactic vaccines (VAX), and curative strategies (CURE).

METHODS

Systematic PubMed searches were conducted to identify ARV, VAX, and CURE studies. Data were extracted on the number of women, date of publication, sources of funding, country of study, and trial phase. Correlates of female participation were assessed.

RESULTS

Women represented a median of 19.2% participants in ARV studies (387), 38.1% in VAX studies (53), and 11.1% in CURE studies (104). Funding source was not correlated with the proportion of female participants in VAX and CURE studies but was for ARV studies (P = 0.03). ARV trials funded by private noncommercial sources had the highest proportion of women, whereas publicly funded trials had the lowest female participation (median 16.7%). The median proportion of women in ARV trials that were fully or partially funded by the National Institutes of Health was significantly lower than the median in trials funded by other sources (19.6% vs. 22.3%, P = 0.001).

CONCLUSIONS

Although women comprise nearly half of people living with HIV, they continue to be under-represented in clinical studies. Despite federal policies that have been established to address this, our study shows that publicly funded ARV trials recruit even fewer women than other trials. There is an urgent need to ensure that HIV clinical studies consider sex/gender dimensions.

Brief Report: Seminal Plasma Anti-HIV Antibodies Trigger Antibody-dependent Cellular Cytotoxicity: Implications for HIV Transmission

Recent evidence from HIV vaccine trials in humans and non-human primates suggests that nonneutralizing antibody functions, such as antibody-dependent cellular cytotoxicity (ADCC), are an important component of vaccine-mediated protection. Whether anti-HIV ADCC antibodies are present in seminal fluid, however, is not known. We assessed whether anti-HIV antibodies within seminal plasma mediate ADCC and activate natural killer (NK) cells. Using matched blood and seminal plasma samples, we detected anti-HIV IgG within samples from all 11 HIV-infected donors. Furthermore, anti-HIV antibodies within the seminal plasma triggered detectable ADCC in 9 of 11 donors and activated NK cells in 6 of 11 donors. The ability of seminal plasma-derived IgG to activate NK cells in an anti-HIV antibody-dependent manner was enhanced when IgG were enriched and other seminal plasma components were removed. These observations have relevance for understanding natural immunity to HIV infection and provide assistance with HIV vaccine design.

Maraviroc and reverse transcriptase inhibitors combinations as potential preexposure prophylaxis candidates

OBJECTIVE

Receptive anal intercourse in both men and women is associated with the highest probability for sexual acquisition of HIV infection. As part of a program to develop an effective prevention strategy, we performed an ex-vivo preclinical evaluation to determine the efficacy of multiple double combinations of maraviroc (MVC) and reverse transcriptase inhibitors (RTIs).

DESIGN

The entry inhibitor, MVC, a nucleotide RTI, tenofovir and two non-nucleoside RTIs, UC781 and TMC120 (dapivirine, DPV), were used in double, combinations against a panel of CCR5-using clade B and clade C HIV-1 isolates and against MVC-escape variants. A gel-formulated version of MVC-DPV combination was also tested.

METHODS

Indicator cells, cocultures of immature dendritic cells with CD4T cells, and colorectal tissue explants were used to assess antiviral activity of drug combinations.

RESULTS

All dual MVC-RTI combinations tested inhibited MVC-sensitive and resistant isolates in cellular and colorectal explants models. All the combinations were positive with no reduction in the activity of MVC. In tissue explants, the combinations against all viral isolates tested produced an increase in the activity of MVC. An initial gel-formulation of MVC-DPV combination showed greater and prolonged antiviral activity of MVC in mucosal tissue explants.

CONCLUSION

This study demonstrates that combinations based on antiretroviral drugs inhibiting HIV transmission at viral entry and reverse transcription have potential as prevention strategies against colorectal transmission of HIV-1 including MVC-resistant isolates. Preclinical evaluation with colorectal tissue explants indicates that a gel-formulation of MVC-DPV is an effective candidate colorectal microbicide.

Morphology-Dependent HIV-Enhancing Effect of Semen-Derived Enhancer of Viral Infection

PAP248-286 is a 39-residue fragment (residues 248 to 286) derived from protease cleavage of prostatic acidic phosphatase in semen. The amyloid fibrils formed in vitro by PAP248-286 can dramatically enhance human immunodeficiency virus (HIV) infection. To our knowledge, we present the first report that the HIV-enhancing potency of fibrils formed by PAP248-286 is morphology dependent. We identified pleomorphic fibrils by transmission electron microscopy in two buffer conditions. Our solid-state NMR data showed that these fibrils consist of molecules in distinct conformations. In agreement with NMR, fluorescence measurements confirmed that they are assembled along different pathways, with distinct molecular structures. Furthermore, our cell-based infectivity tests detected distinct HIV-enhancing potencies for fibrils in distinct morphologies. In addition, our transmission electron microscopy and NMR results showed that semen-derived enhancer of viral infection fibrils formed in sodium bicarbonate buffer remain stable over time, but semen-derived enhancer of viral infection fibrils formed in phosphate buffered saline keep evolving after the initial 7 days incubation period. Given time, most of the assemblies in phosphate buffered saline will turn into elongated thin fibrils. They have similar secondary structure but different packing than thin fibrils formed initially after 7 days incubation.

Condom effectiveness in reducing heterosexual HIV transmission: a systematic review and meta-analysis of studies on HIV serodiscordant couples

OBJECTIVE

This systematic review and meta-analysis aimed to reassess the effectiveness of condoms in reducing heterosexual transmission of HIV.

METHODS

Medline, Scopus, and the ISI Web of Science databases were searched up to June 2014. Eligible studies were synthesized using random-effects models.

RESULTS

Twenty-five studies with 10,676 HIV serodiscordant heterosexual couples were analyzed. The risk of HIV transmission was considerably lower among couples that were always using condoms compared to never-users (RR: 0.29, 95% CI: 0.20-0.43) or inconsistent users (RR:  0.23, 0.13-0.40). The protective effect was slightly higher when the male rather than the female partner was infected (RR: 0.31, 0.20-0.48; vs. RR: 0.44, 0.24-0.80), and very high in Asian settings (RR: 0.06, 0.01-0.46).

CONCLUSIONS

Though imperfect, condoms reduce HIV transmission by more than 70% when used consistently by HIV serodiscordant heterosexual couples. Social, cultural and biological differences need to be studied further to inform projection modelers and policy makers.

Gender Differences in Adherence and Response to Antiretroviral Treatment in the Stratall Trial in Rural District Hospitals in Cameroon

BACKGROUND

Evidence of gender differences in antiretroviral treatment (ART) outcomes in sub-Saharan Africa is conflicting. Our objective was to assess gender differences in (1) adherence to ART and (2) virologic failure, immune reconstitution, mortality, and disease progression adjusting for adherence.

METHODS

Cohort study among 459 ART-naive patients followed up 24 months after initiation in 2006-2010 in 9 rural district hospitals. Adherence to ART was assessed using (1) a validated tool based on multiple patient self-reports and (2) antiretroviral plasma concentrations. The associations between gender and the outcomes were assessed using multivariate mixed models or accelerated time failure models.

RESULTS

One hundred thirty-five patients (29.4%) were men. At baseline, men were older, had higher body mass index and hemoglobin level, and received more frequently efavirenz than women. Gender was not associated with self-reported adherence (P = 0.872, 0.169, and 0.867 for moderate adherence, low adherence, and treatment interruption, respectively) or with antiretroviral plasma concentrations (P = 0.549 for nevirapine/efavirenz). In contrast, male gender was associated with virologic failure [odds ratio: 2.18, 95% confidence interval (CI): 1.31 to 3.62, P = 0.003], lower immunologic reconstitution (coefficient: -58.7 at month 24, 95% CI: -100.8 to -16.6, P = 0.006), and faster progression to death (time ratio: 0.30, 95% CI: 0.12 to 0.78, P = 0.014) and/or to World Health Organization stage 4 event (time ratio: 0.27, 95% CI: 0.09 to 0.79, P = 0.017).

CONCLUSIONS

Our study provides important evidence that African men are more vulnerable to ART failure than women and that the male vulnerability extends beyond adherence issues. Additional studies are needed to determine the causes for this vulnerability to optimize HIV care. However, personalized adherence support remains crucial.

Homosexual men in HIV serodiscordant relationships: implications for HIV treatment as prevention research

Introduction

Studies in heterosexual HIV serodiscordant couples have provided critical evidence on the role of HIV treatments in reducing HIV transmission risk. However, there are limited data regarding the effect of treatment on HIV transmission in homosexual male couples. We examined features of male homosexual HIV serodiscordant relationships that may impact upon the design of HIV treatment and transmission studies.

Methods

Data were from a prospective cohort study of HIV-negative homosexual men in Sydney, Australia. Men were followed up with six-monthly interviews and annual testing for HIV. Characteristics of men in HIV serodiscordant and seroconcordant relationships at baseline were compared, and a longitudinal analysis performed of rate of relationship break-up and of HIV incidence.

Results

At baseline, 5.5% of participants (n=79) had an HIV-positive partner. Most (80.8%) of these relationships were non-monogamous, and 36.7% of men reported recent unprotected anal intercourse (UAI) with casual partners. The rate of relationship break-up was 29.5 per 100 person-years. Half of men in serodiscordant relationships (49.4%) reported recent UAI with their regular partners. HIV incidence was 2.2 per 100 person-years. It was substantially higher in relationships of less than one year's duration (6.1 per 100 person-years) and in men who reported unprotected receptive anal intercourse with ejaculation with their regular partners (15.5 per 100 person-years).

Conclusions

Levels of HIV transmission risk and incidence were high, particularly in early relationships. Rates of relationship break-up were high. These data suggest that studies of HIV treatments and transmission in homosexual serodiscordant couples should focus on early relationships so as not to underestimate risk, and sample sizes must allow for high rates of relationship break-up.

Sexual risk behaviors and HIV risk among Americans aged 50 years or older: a review

Although HIV-related sexual risk behaviors have been studied extensively in adolescents and young adults, there is limited information about these behaviors among older Americans, which make up a growing segment of the US population and an understudied population. This review of the literature dealing with sexual behaviors that increase the risk of becoming HIV-infected found a low prevalence of condom use among older adults, even when not in a long-term relationship with a single partner. A seminal study by Schick et al published in 2010 reported that the prevalence of condom use at last intercourse was highest among those aged 50–59 years (24.3%; 95% confidence interval, 15.6–35.8) and declined with age, with a 17.1% prevalence among those aged 60–69 years (17.1%; 95% confidence interval, 7.3–34.2). Studies have shown that older Americans may underestimate their risk of becoming HIV-infected. Substance use also increases the risk for sexual risk behaviors, and studies have indicated that the prevalence of substance use among older adults has increased in the past decade. As is the case with younger adults, the prevalence of HIV infections is elevated among ethnic minorities, drug users (eg, injection drug users), and men who have sex with men. When infected, older adults are likely to be diagnosed with HIV-related medical disorders later in the course of illness compared with their younger counterparts. Physicians are less likely to discuss sexual risk behaviors with older adults and to test them for HIV compared with younger adults. Thus, it is important to educate clinicians about sexual risk behaviors in the older age group and to design preventive interventions specifically designed for older adults.

Detection of Simian Immunodeficiency Virus in Semen, Urethra, and Male Reproductive Organs during Efficient Highly Active Antiretroviral Therapy

A number of men receiving prolonged suppressive highly active antiretroviral therapy (HAART) still shed human immunodeficiency virus (HIV) in semen. To investigate whether this seminal shedding may be due to poor drug penetration and/or viral production by long-lived cells within male genital tissues, we analyzed semen and reproductive tissues from macaques chronically infected with simian immunodeficiency virus mac251 (SIVmac251) who were treated for 4 months with HAART, which was intensified over the last 7 weeks with an integrase inhibitor. We showed that a subset of treated animals continued shedding SIV in semen despite efficient HAART. This shedding was not associated with low antiretroviral drug concentrations in semen or in testis, epididymis, seminal vesicles, and prostate. HAART had no significant impact on SIV RNA in the urethra, whereas it drastically reduced SIV RNA levels in the prostate and vas deferens and to a lesser extent in the epididymis and seminal vesicle. The only detectable SIV RNA-positive cells within the male genital tract after HAART were urethral macrophages. SIV DNA levels in genital tissues were not decreased by HAART, suggesting the presence throughout the male genital tract of nonproductively infected cells. In conclusion, our results demonstrate that 4 months of HAART induced variable and limited control of viral infection in the male reproductive organs, particularly in the urethra, and suggest that infected long-lived cells in the male genital tract may be involved in persistent seminal shedding during HAART. These results pave the way for further investigations of male genital organ infection in long-term-treated infected individuals.

IMPORTANCE

A substantial subset of men receiving prolonged HAART suppressing viral loads in the blood still harbor HIV in semen, and cases of sexual transmission have been reported. To understand the origin of this persistence, we analyzed the semen and male reproductive tissues from SIV-infected macaques treated with HAART. We demonstrated that persistent seminal shedding was not linked to poor drug penetration in semen or semen-producing prostate, seminal vesicle, epididymis, and testis. We revealed that HAART decreased SIV RNA to various extents in all male genital organs, with the exception of the urethra, in which SIV RNA(+) macrophages were observed despite HAART. Importantly, HAART did not impact SIV DNA levels in the male genital organs. These results suggest that infection of male genital organs, and particularly the urethra, could be involved in the release of virus in semen during HAART.

Adolescent girls and young women: key populations for HIV epidemic control

INTRODUCTION

At the epicentre of the HIV epidemic in southern Africa, adolescent girls and young women aged 15-24 contribute a disproportionate ~30% of all new infections and seroconvert 5-7 years earlier than their male peers. This age-sex disparity in HIV acquisition continues to sustain unprecedentedly high incidence rates, and preventing HIV infection in this age group is a pre-requisite for achieving an AIDS-free generation and attaining epidemic control.

DISCUSSION

Adolescent girls and young women in southern Africa are uniquely vulnerable to HIV and have up to eight times more infection than their male peers. While the cause of this vulnerability has not been fully elucidated, it is compounded by structural, social and biological factors. These factors include but are not limited to: engagement in age-disparate and/or transactional relationships, few years of schooling, experience of food insecurity, experience of gender-based violence, increased genital inflammation, and amplification of effects of transmission co-factors. Despite the large and immediate HIV prevention need of adolescent girls and young women, there is a dearth of evidence-based interventions to reduce their risk. The exclusion of adolescents in biomedical research is a huge barrier. School and community-based education programmes are commonplace in many settings, yet few have been evaluated and none have demonstrated efficacy in preventing HIV infection. Promising data are emerging on prophylactic use of anti-retrovirals and conditional cash transfers for HIV prevention in these populations.

CONCLUSIONS

There is an urgent need to meet the HIV prevention needs of adolescent girls and young women, particularly those who are unable to negotiate monogamy, condom use and/or male circumcision. Concerted efforts to expand the prevention options available to these young women in terms of the development of novel HIV-specific biomedical, structural and behavioural interventions are urgently needed for epidemic control. In the interim, a pragmatic approach of integrating existing HIV prevention efforts into broader sexual reproductive health services is a public health imperative.

The role of dendritic cells in driving genital tract inflammation and HIV transmission risk: are there opportunities to intervene?

Effective prevention of new HIV infections will require an understanding of the mechanisms involved in HIV acquisition. HIV transmission across the female genital tract is the major mode of new HIV infections in sub-Saharan Africa and involves complex processes, including cell activation, inflammation and recruitment of HIV target cells. Activated CD4(+) T-cells, dendritic cells (DC) and macrophages have been described as targets for HIV at the genital mucosa. Activation of these cells may occur in the presence of sexually-transmitted infections, disturbances of commensal flora and other inflammatory processes. In this review, we discuss causes and consequences of inflammation in the female genital tract, with a focus on DC. We describe the central role these cells may play in facilitating or preventing HIV transmission across the genital mucosa, and in the initial recognition of HIV and other pathogens, allowing activation of an adaptive immune response to infection. We discuss studies that investigate interventions to limit DC activation, inflammation and HIV transmission. This knowledge is essential in the development of novel strategies for effective HIV control, including microbicides and pre-exposure prophylaxis.

The need for multipurpose prevention technologies in sub-Saharan Africa

Women bear a disproportionate burden of the HIV epidemic in sub-Saharan Africa and account for about 60% of all adults living with HIV in that region. Young women, including adolescent girls, unable to negotiate mutual faithfulness and/or condom use with their male partners are particularly vulnerable. In addition to the high HIV burden, women in Africa also experience high rates of other sexually transmitted infections and unwanted pregnancies. The development of technologies that can simultaneously meet these multiple sexual reproductive health needs would therefore be extremely beneficial in the African setting.

The Opposites Attract Study of viral load, HIV treatment and HIV transmission in serodiscordant homosexual male couples: design and methods

BACKGROUND

Studies in heterosexual HIV serodiscordant couples have provided critical evidence on the role of HIV treatments and undetectable viral load in reducing the risk of HIV transmission. There is very limited data on the risk of transmission from anal sex in homosexual male serodiscordant couples.

METHODS/DESIGN

The Opposites Attract Study is an observational prospective longitudinal cohort study of male homosexual serodiscordant partnerships running from 2012 to 2015 and conducted in clinics throughout Australia, Brazil and Thailand. Couples attend two or more clinic visits per year. The HIV-positive partner's viral load is tested and the HIV-negative partner is tested for HIV antibodies at every clinic visit. Results from any tests for sexually transmitted infections are also collected. Detailed behavioural questionnaires are completed by both partners at the time of each visit. The primary research question is whether HIV incidence is lower in those couples where the HIV-positive partner is receiving HIV treatment compared to couples where he is not receiving treatment. A voluntary semen sub-study will examine semen plasma viral load in a subsample of HIV-positive partners in Sydney, Rio de Janeiro and Bangkok. In cases of seroconversion of the initially HIV-negative partner, phylogenetic analysis will be conducted at the end of the study on virus from stored blood samples from both partners to determine if the infection came from the HIV-positive study partner. Men in new serodiscordant relationships will specifically be targeted for recruitment.

DISCUSSION

This study will provide critical data on the reduction in HIV transmission risk associated with being on HIV treatment in homosexual male serodiscordant couples in different regions of the world. Data from men in new relationships will be particularly valuable given that the highest transmission risk is in the first year of serodiscordant relationships. Furthermore, the detailed behavioural and attitudinal data from the participant questionnaires will allow exploration of many contextual factors associated with HIV risk, condom use and the negotiation of sexual practice within couples.

Oral pre-exposure prophylaxis (PrEP) for prevention of HIV in serodiscordant heterosexual couples in the United States: opportunities and challenges

Oral HIV pre-exposure prophylaxis (PrEP) is a promising new biomedical prevention approach in which HIV-negative individuals are provided with daily oral antiretroviral medication for the primary prevention of HIV-1. Several clinical trials have demonstrated efficacy of oral PrEP for HIV prevention among groups at high risk for HIV, with adherence closely associated with level of risk reduction. In the United States (US), three groups have been prioritized for initial implementation of PrEP-injection drug users, men who have sex with men at substantial risk for HIV, and HIV-negative partners within serodiscordant heterosexual couples. Numerous demonstration projects involving PrEP implementation among MSM are underway, but relatively little research has been devoted to study PrEP implementation in HIV-serodiscordant heterosexual couples in the US. Such couples face a unique set of challenges to PrEP implementation at the individual, couple, and provider level with regard to PrEP uptake and maintenance, adherence, safety and toxicity, clinical monitoring, and sexual risk behavior. Oral PrEP also provides new opportunities for serodiscordant couples and healthcare providers for primary prevention and reproductive health. This article provides a review of the critical issues, challenges, and opportunities involved in the implementation of oral PrEP among HIV-serodiscordant heterosexual couples in the US.

Estimating per-act HIV transmission risk: a systematic review

BACKGROUND

Effective HIV prevention programs rely on accurate estimates of the per-act risk of HIV acquisition from sexual and parenteral exposures. We updated the previous risk estimates of HIV acquisition from parenteral, vertical, and sexual exposures, and assessed the modifying effects of factors including condom use, male circumcision, and antiretroviral therapy.

METHODS

We conducted literature searches to identify new studies reporting data regarding per-act HIV transmission risk and modifying factors. Of the 7339 abstracts potentially related to per-act HIV transmission risk, three meta-analyses provided pooled per-act transmission risk probabilities and two studies provided data on modifying factors. Of the 8119 abstracts related to modifying factors, 15 relevant articles, including three meta-analyses, were included. We used fixed-effects inverse-variance models on the logarithmic scale to obtain updated estimates of certain transmission risks using data from primary studies, and employed Poisson regression to calculate relative risks with exact 95% confidence intervals for certain modifying factors.

RESULTS

Risk of HIV transmission was greatest for blood transfusion, followed by vertical exposure, sexual exposures, and other parenteral exposures. Sexual exposure risks ranged from low for oral sex to 138 infections per 10,000 exposures for receptive anal intercourse. Estimated risks of HIV acquisition from sexual exposure were attenuated by 99.2% with the dual use of condoms and antiretroviral treatment of the HIV-infected partner.

CONCLUSION

The risk of HIV acquisition varied widely, and the estimates for receptive anal intercourse increased compared with previous estimates. The risk associated with sexual intercourse was reduced most substantially by the combined use of condoms and antiretroviral treatment of HIV-infected partners.

Transcytosis of HIV-1 through vaginal epithelial cells is dependent on trafficking to the endocytic recycling pathway

Background

While it is accepted that viruses can enter epithelial cells by endocytosis, the lack of an established biological mechanism for the trafficking of infectious virions through vaginal epithelial cells and their release from the plasma membrane has contributed to ongoing controversy about whether endocytosis is a mere artifact of some cell culture systems and whether squamous vaginal epithelial cells are even relevant as it pertains to HIV-1 transmission.

Methodology/Principal Findings

In this study, we investigated the intracellular trafficking pathway that HIV-1 exploits to transcytose vaginal epithelial cells. The reduction of endosome tubulation by recycling endosome inhibitors blocked transcytosis of HIV-1 in a cell culture and transwell system. In addition, we demonstrate that although heat-inactivated virus was endocytosed as efficiently as native virus, heat-inactivated virus was trafficked exclusively to the lysosomal pathway for degradation following endocytosis. Lysosomal protease-specific inhibitors blocked the degradation of inactivated virions. Immunofluorescence analysis not only demonstrated that HIV-1 was inside the cells but the different colocalization pattern of native vs. heat inactivated virus with transferrin provided conclusive evidence that HIV-1 uses the recycling pathway to get across vaginal epithelial cells.

Conclusions/Significance

Altogether, our findings demonstrate the precise intracellular trafficking pathway utilized by HIV-1 in epithelial cells, confirms that HIV-1 transcytosis through vaginal epithelial cells is a biological phenomenon and brings to light the differential intracellular trafficking of native vs heat-inactivated HIV-1 which with further exploration could prove to provide valuable insights that could be used in the prevention of transcytosis/transmission of HIV-1 across the mucosal epithelia.

Expanded HIV testing in low-prevalence, high-income countries: a cost-effectiveness analysis for the United Kingdom

Objective

In many high-income countries with low HIV prevalence, significant numbers of persons living with HIV (PLHIV) remain undiagnosed. Identification of PLHIV via HIV testing offers timely access to lifesaving antiretroviral therapy (ART) and decreases HIV transmission. We estimated the effectiveness and cost-effectiveness of HIV testing in the United Kingdom (UK), where 25% of PLHIV are estimated to be undiagnosed.

Design

We developed a dynamic compartmental model to analyze strategies to expand HIV testing and treatment in the UK, with particular focus on men who have sex with men (MSM), people who inject drugs (PWID), and individuals from HIV-endemic countries.

Methods

We estimated HIV prevalence, incidence, quality-adjusted life years (QALYs), and health care costs over 10 years, and cost-effectiveness.

Results

Annual HIV testing of all adults could avert 5% of new infections, even with no behavior change following HIV diagnosis because of earlier ART initiation, or up to 18% if risky behavior is halved. This strategy costs £67,000–£106,000/QALY gained. Providing annual testing only to MSM, PWID, and people from HIV-endemic countries, and one-time testing for all other adults, prevents 4–15% of infections, requires one-fourth as many tests to diagnose each PLHIV, and costs £17,500/QALY gained. Augmenting this program with increased ART access could add 145,000 QALYs to the population over 10 years, at £26,800/QALY gained.

Conclusions

Annual HIV testing of key populations in the UK is very cost-effective. Additional one-time testing of all other adults could identify the majority of undiagnosed PLHIV. These findings are potentially relevant to other low-prevalence, high-income countries.

Risk for HIV following a diagnosis of syphilis, gonorrhoea or chlamydia: 328,456 women in Florida, 2000-2011

Several effective interventions are available for preventing HIV in women. Targeting interventions requires understanding their risk of acquiring HIV. We used surveillance data to estimate risks of HIV acquisition for 13-59-year-old women following a diagnosis of syphilis, gonorrhoea or chlamydia in Florida during 2000-2009. We excluded women reported with HIV before their STI, and measured HIV reported subsequent to STI (through 2011). Rates were compared to women with no reported STI. A total of 328,456 women had: syphilis (3325), gonorrhoea (67,784) or chlamydia (257,347). During 2,221,944 person-years of follow-up, 2118 of them were diagnosed with HIV. For women with no STI reported, during 64,763,832 person-years, 19,531 were reported with HIV. The crude rate of subsequent HIV diagnosis (per 100,000 person-years) was higher for women diagnosed with syphilis (597.9), gonorrhoea (171.3) or chlamydia (66.3) than women with no STI (30.2). Annual rates of HIV decreased over-all by 61.8% between 2001 and 2011. Women with syphilis or gonorrhoea were at highest risk for HIV and therefore might benefit from intensive counselling. However, they represented only a small fraction of the women who acquired HIV. Most cases of HIV infection among women occurred among the large group of women who were not at highest risk.

Anal sex, vaginal sex and HIV risk among female sex workers in Papua New Guinea

Female sex workers (FSW) are considered one of the key affected populations in Papua New Guinea at risk of acquiring HIV. An integrated bio-behavioral survey of sex workers in Port Moresby was conducted to determine the nature and extent of this risk. About half (51.1 %) of the 411 FSW who reported having any sexual intercourse with clients had engaged in both anal and vaginal intercourse with clients in the last 6 months. In spite of having poorer HIV knowledge (OR95 % CI = 0.14-0.34), FSW who had anal intercourse with clients were significantly more likely to have used a condom at the last vaginal intercourse with a client (OR95 % CI = 1.04-2.87). Similarly, FSW who had anal intercourse with regular and casual partners were significantly more likely to have used a condom at the last vaginal intercourse. Those who engaged in both anal and vaginal intercourse with clients had similar condom use for both vaginal and anal intercourse, with the majority (78.1 %) using a condom at the last occasion for both vaginal and anal intercourse. These FSW may have different risk and protective factors that affect their use of condom during sexual intercourse. Further research is needed to investigate this difference between those who practice anal intercourse and those who do not in order to provide evidence for better programming.

PREVALENCE OF AND FACTORS ASSOCIATED WITH ORAL SEX AMONG RURAL AND URBAN MALAWIAN MEN

Despite medical evidence that female-to-male oral sex (fellatio) carries a lower risk for HIV transmission than unprotected vaginal intercourse, little research exists on the practice of fellatio in Africa. We used two samples of men from Malawi-one rural and one urban-to examine the prevalence of oral sex. While 97% of the rural sample and 87% of the urban sample reported having had vaginal sex, just 2% and 12%, respectively, said they had ever received oral sex. Only half of the rural sample, and less than three quarters of the urban sample, reported having heard of oral sex. Education, exposure to newspapers and television, and condom use significantly predicted oral sex knowledge after controlling for other confounding factors, while exposure to radio did not. The large gap between sexual activity and oral sex prevalence suggests that fellatio should be taken into consideration as a potential component of an HIV prevention strategy, but further quantitative and qualitative research that includes women as well as men is needed to understand potential benefits and drawbacks.

Toward a more complete understanding of reactions to hooking up among college women

Hooking up, a relatively common behavior among young adults, refers to a casual sexual encounter, ranging from kissing to sexual intercourse, without an expectation of ongoing physical encounters or relational commitment. Reactions to hooking up have examined psychosocial outcomes as a proxy for specific reactions. The present study examined the reactions of 190 college women, with a specific focus on the effect of hooking up on their social/peer network, their sexual/romantic sense of self, and their academic performance. Results demonstrated large positive effects for sexual/romantic reactions and social/academic engagement reactions in comparison with negative personal reactions. In addition, higher ratings of anxious attachment, loneliness, and relational/intimacy sex motives were related to less positive reactions, highlighting the importance of attachment and motivations behind hookup experiences. Implications for educational practice and future research are offered.

A systematic review of heterosexual anal intercourse and its role in the transmission of HIV and other sexually transmitted infections in Papua New Guinea

Background

Papua New Guinea (PNG) has a high burden of sexually transmitted infections (STIs) and the highest adult HIV prevalence in the Pacific region. Despite this burden of disease, heterosexual anal intercourse (HAI) has rarely been considered. Given the increasing number of, and interest in, behavioural surveys in PNG and the changing nature of PNG’s HIV epidemic, it is timely to conduct a systematic review of HAI in PNG order to improve sexual health.

Methods

We performed a systematic review of HAI in PNG as reported in peer-reviewed and non-peer-reviewed publications for the period 1950–May 2012. The search strategy identified 475 publications. After screening by geographical location, topic and methodology, we identified 23 publications for full text review, following which 13 publications were included in the final review. Using data from the review, we performed a risk equation analysis to demonstrate the potential impact of HAI on HIV acquisition and incidence in PNG.

Results

There is a paucity of well-informed behavioural research on HAI in PNG. Inconsistency in key questions on HAI made it impossible to conduct a meta-analysis. The data available on HAI shows that it is practiced in all geographical areas and among all populations. Of those who reported HAI, rates varied from as low as 8% to as high as 77% depending on the recall period and partner type. Condom use during HAI was consistently low. Our risk equation analysis indicates that even if only 20% of females engage in HAI, and only 10% of sex acts involve HAI, the total number of new HIV infections among females would be 40% greater than if vaginal intercourse only occurred.

Conclusions

Our findings of indicate that HAI may be an important driver of the HIV epidemic in PNG. In order to improve the sexual health of Papua New Guineans, efforts are required to improve behavioural surveillance of HAI as well as develop national HIV/STI programing and policy to better address the risks associated with unprotected HAI.

Nonhuman primate models for HIV/AIDS vaccine development

The development of HIV vaccines has been hampered by the lack of an animal model that can accurately predict vaccine efficacy. Chimpanzees can be infected with HIV-1 but are not practical for research. However, several species of macaques are susceptible to the simian immunodeficiency viruses (SIVs) that cause disease in macaques, which also closely mimic HIV in humans. Thus, macaque-SIV models of HIV infection have become a critical foundation for AIDS vaccine development. Here we examine the multiple variables and considerations that must be taken into account in order to use this nonhuman primate (NHP) model effectively. These include the species and subspecies of macaques, virus strain, dose and route of administration, and macaque genetics, including the major histocompatibility complex molecules that affect immune responses, and other virus restriction factors. We illustrate how these NHP models can be used to carry out studies of immune responses in mucosal and other tissues that could not easily be performed on human volunteers. Furthermore, macaques are an ideal model system to optimize adjuvants, test vaccine platforms, and identify correlates of protection that can advance the HIV vaccine field. We also illustrate techniques used to identify different macaque lymphocyte populations and review some poxvirus vaccine candidates that are in various stages of clinical trials. Understanding how to effectively use this valuable model will greatly increase the likelihood of finding a successful vaccine for HIV.

Male involvement in sexual and reproductive health in the Mendi district, Southern Highlands province of Papua New Guinea: a descriptive study

BACKGROUND

Lack of male involvement and support for sexual and reproductive health services is seen by many Papua New Guinean women as a barrier to accessing services. Poor utilization of services by both men and women is reflected in high maternal mortality and high rates of HIV/AIDS and sexually transmitted infections in the Southern Highlands Province. It is therefore important to understand the type of services provided, men's perceptions of these services and the Health Sector's capacity to involve men in its programs.

METHODS

Information from interviews of married men, officers in charge of health facilities, and information from a focus group discussion with village leaders was collected to assess possible constraints to reproductive and sexual health care delivery.

RESULTS

Although many men had heard about antenatal care, supervised births, family planning and sexually transmitted infections including, HIV/AIDS, many were unaware of their importance and of the types of services provided to address these issues. There was a very strong association between men's literacy and their knowledge of Sexual and Reproductive Health (SRH) issues, their discussion of these issues with their wives and their wives' utilisation of sexual and reproductive health services. Some men considered SRH services to be important but gave priority to social obligations. Although men made most decisions for sexual and reproductive issues, pregnancy, child birth and rearing of children were regarded as women's responsibilities. Knowledge of HIV/AIDS appeared to have changed sexual behaviour in some men. Services for men in this rural setting were inadequate and service providers lacked the capacity to involve men in reproductive health issues.

CONCLUSION

Poor knowledge, socio-cultural factors and inadequate and inappropriate services for men hampered utilization of services and impaired support for their wives' service utilization. Programmatic and policy initiatives should focus on improving service delivery to accommodate men in sexual and reproductive health.

Gender differences in heterosexual anal sex practices among women and men in substance abuse treatment

Heterosexual anal intercourse (HAI) is an understudied risk behavior among women and men in substance abuse treatment. Rates of HAI for women (n = 441) and men (n = 539) were identified for any, main and casual partners. More men (32.8 %) than women (27.1 %) reported engaging in HAI in the previous 90 days. These rates are higher than those reported for both men (6.0-15.9 %) and women (3.5-13.0 %) ages 25-59 in the National Survey of Sexual Health and Behavior. Men were significantly more likely to report HAI with their casual partners (34.1 %) than women (16.7 %). In a logistic regression model generated to identify associations between HAI and variables previously shown to be related to high risk sexual behavior, being younger, bisexual, and White were significantly associated with HAI. For men, having more sex partners was also a significant correlate. HAI is a logical target for increased focus in HIV prevention interventions.

Anal sex and associated HIV-related sexual risk factors among female sex workers in Andhra Pradesh, India

BACKGROUND

This study aims to understand the correlates of anal sex practices among female sex workers (FSWs) and examine the association of anal sex with HIV-related sexual risk factors in Andhra Pradesh, India.

METHODS

A cross-sectional behavioural survey was conducted in 2011 among 795 FSWs aged 18 years or older. Probability-based cluster sampling was used to select respondents from sex work hotspots.

RESULTS

One-quarter (23%) of FSWs had practiced anal sex in the last year. The odds of practicing anal sex were higher among FSWs aged 35 years or more than in those aged less than 25 years (adjusted odds ratio (AOR): 2.05, P<0.05), in those formerly married compared to those currently married (AOR: 1.88, P<0.01), in those having an income only from sex work compared to those having additional sources of income (AOR: 1.54, P<0.05), those reporting heavy alcohol consumption compared to those who did not (AOR: 2.80, P<0.01) and those who experienced violence compared to those who had not (AOR: 2.80, P<0.01). FSWs practicing anal sex were more likely to experience sexually transmissible infection (STI) related symptoms than those practicing only vaginal sex. There was no association between anal sex practice and condom use.

CONCLUSIONS

Anal sex is associated with STI symptoms, a factor for HIV risk. HIV intervention programmes need to educate FSWs about the risks associated with anal sex.

Homeostatic properties of Lactobacillus jensenii engineered as a live vaginal anti-HIV microbicide

Background

Vaginal probiotics are investigated as a binary strategy for prevention of bacterial vaginosis and HIV. We applied an innovative experimental model using primary and immortalized human cervical and vaginal epithelial cells to assess the functional properties of Lactobacillus jensenii, a predominant constituent of the healthy vaginal microbiome, engineered to express the HIV-1 entry inhibitor modified cyanovirin-N (mCV-N). In this model bacteria colonize the epithelial cells over a period of 24-72 h. Staurosporine and the Toll-like receptor 2/6 ligand macrophage-activating lipopeptide-2 (MALP-2) serve as positive controls for apoptosis and proinflammatory activation, respectively. In 24-hour intervals, the colonized epithelium is assessed microscopically, supernatants are collected for measurement of soluble immunoinflammatory mediators and production of CV-N, and cells are lysed for assessment of: 1) apoptosis by cleaved versus total caspase-3 assay; 2) NF-κB activation by a luciferase reporter assay; or 3) epithelia-associated colony forming units (CFU) in Brucella agar.

Results

Wild type (WT) L. jensenii 1153 consistently colonized cervical and vaginal cells in the absence of epithelial damage and apoptosis. The bioengineered derivatives expressing mCV-N or control plasmids showed the same stable colonization pattern, which was reproducible between technologists and bacterial batches (CFU coefficient of variation <10% within and between experiments and epithelial cell types). MALP-2 activated NF-κB and caused fold-increased levels of proinflammatory mediators with clinically established significance in the cervicovaginal environment (IL-1α, IL-1β, IL-6, TNF-α, IL-8, RANTES, MIP-3α, and ICAM-1), measured by a multiplex electrochemiluminescence assay. At the same time levels of protective anti-inflammatory mediators interleukin 1 receptor antagonist (IL-1RA) and secretory leukocyte protease inhibitor (SLPI), both measured by ELISA, remained constant (IL-1RA) or moderately increased (SLPI). Similarly to MALP-2, colonization by L. jensenii WT activated NF-κB; however, unlike the synthetic TLR2/6 ligand, the live microorganisms did not induce significant changes in the secreted levels across all inflammation-associated proteins. The mCV-N production and function were confirmed by western blot and a HIV-1 gp120 binding assay, respectively. The bioengineered lactobacilli expressed mCV-N with anti-HIV activity preserved in the epithelial cell context and caused no significant immunoinflammatory changes as compared to the WT L. jensenii.

Conclusions

These results highlight the translational value of the colonization model and justify further clinical investigation of the homeostatic and anti-HIV effectiveness of the L. jensenii derivates.

Heterosexual HIV-1 infectiousness and antiretroviral use: systematic review of prospective studies of discordant couples

BACKGROUND

Recent studies have estimated the reduction in HIV-1 infectiousness with antiretroviral therapy (ART), but high-quality studies such as randomized controlled trials, accompanied by rigorous adherence counseling, are likely to overestimate the effectiveness of treatment-as-prevention in real-life settings.

METHODS

We attempted to summarize the effect of ART on HIV transmission by undertaking a systematic review and meta-analysis of HIV-1 infectiousness per heterosexual partnership (incidence rate and cumulative incidence over study follow-up) estimated from prospective studies of discordant couples. We used random-effects Poisson regression models to obtain summary estimates. When possible, the analyses were further stratified by direction of transmission (man-to-woman or woman-to-man) and economic setting (high- or low-income countries). Potential causes of heterogeneity of estimates were explored through subgroup analyses.

RESULTS

Fifty publications were included. Nine allowed comparison between ART and non-ART users within studies (ART-stratified studies), in which summary incidence rates were 3.6/100 person-years (95% confidence interval = 2.0-6.5) and 0.2/100 person-years (0.07-0.7) for non-ART- and ART-using couples, respectively (P < 0.001), constituting a 91% (79-96%) reduction in per-partner HIV-1 incidence rate with ART use. The 41 studies that did not stratify by ART use provided estimates with high levels of heterogeneity (I statistic) and few reported levels of ART use, making interpretation difficult. Nevertheless, estimates tended to be lower with ART use. Infectiousness tended to be higher for low-income than high-income settings, but there was no clear pattern by direction of transmission (man-to-woman and woman-to-man).

CONCLUSIONS

ART substantially reduces HIV-1 infectiousness within discordant couples, based on observational studies, and could play a major part in HIV-1 prevention efforts. However, the non-zero risk from partners receiving ART demonstrates that appropriate counseling and other risk-reduction strategies for discordant couples are still required. Additional estimates of ART effectiveness by adherence level from real-life settings will be important, especially for persons starting treatment early without symptoms.

Modernization, sexual risk-taking, and gynecological morbidity among Bolivian Forager-horticulturalists

Sexual risk-taking and reproductive morbidity are common among rapidly modernizing populations with little material wealth, limited schooling, minimal access to modern contraception and healthcare, and gendered inequalities in resource access that limit female autonomy in cohabiting relationships. Few studies have examined how modernization influences sexual risk-taking and reproductive health early in demographic transition. Tsimane are a natural fertility population of Bolivian forager-farmers; they are not urbanized, reside in small-scale villages, and lack public health infrastructure. We test whether modernization is associated with greater sexual risk-taking, report prevalence of gynecological morbidity (GM), and test whether modernization, sexual risk-taking and parity are associated with greater risk of GM. Data were collected from 2002-2010 using interviews, clinical exams, and laboratory analysis of cervical cells. We find opposing effects of modernization on both sexual risk-taking and risk of GM. Residential proximity to town and Spanish fluency are associated with greater likelihood of men's infidelity, and with number of lifetime sexual partners for men and women. However, for women, literacy is associated with delayed sexual debut after controlling for town proximity. Fifty-five percent of women present at least one clinical indicator of GM (n = 377); 48% present inflammation of cervical cells, and in 11% the inflammation results from sexually transmitted infection (trichomoniasis). Despite having easier access to modern healthcare, women residing near town experience greater likelihood of cervical inflammation and trichomoniasis relative to women in remote villages; women who are fluent in Spanish are also more likely to present trichomoniasis relative to women with moderate or no fluency. However, literate women experience lower likelihood of trichomoniasis. Parity has no effect on risk of GM. Our results suggest a net increase in risk of reproductive morbidity among rapidly modernizing, resource-stressed populations.

Genital immunology and HIV susceptibility in young women

Women account for a substantial majority of HIV infections in endemic regions, where women are also infected at a much younger age than men. Part of this epidemiological skewing is due to socio-cultural factors, but it is clear that biological factors enhance the susceptibility of women--particularly young women--to HIV acquisition after sexual exposure. These factors, including important differences in mucosal immunology at the site of genital HIV exposure, are the focus of this concise review. Compared to heterosexual men, women have an increased surface area of mucosal HIV exposure, increased mucosal expression of the HIV co-receptor CCR5 and a greater probability of virus exposure on the rectal mucosa. Differences that are specific to young women include a pro-inflammatory immune environment and a proportionate increase in single-cell, columnar genital epithelium. These important biological reasons for enhanced HIV susceptibility in young women highlight the need for targeted HIV prevention within this vulnerable population.