The role of heterosexual anal intercourse for HIV transmission in developing countries: are we ready to draw conclusions?

How Stigma Toward Anal Sexuality Promotes Concealment and Impedes Health-Seeking Behavior in the U.S. Among Cisgender Men Who Have Sex with Men

Gay, bisexual, and other men who have sex with men (MSM) experience alarming HIV disparities alongside sub-optimal engagement in HIV interventions. Among MSM, stigma toward anal sexuality could interfere with engagement in HIV prevention, yet few studies have examined MSM perspectives on anal sex stigma or its health-related sequelae. Guided by theory, we aimed to characterize anal sex stigma, related sexual concerns, and barriers to health seeking, like concealment. We elicited community input by purposively interviewing 10 experts in MSM health and then 25 racially, ethnically, and geographically diverse cisgender MSM. Participants reported experienced, internalized, and anticipated forms of anal sex stigma that inhibited health seeking. Experienced stigma, including direct and observed experiences as well as the absence of sex education and information, contributed to internalized stigma and anticipation of future devaluation. This process produced psychological discomfort and concealment of health-related aspects of anal sexuality, even from potentially supportive sexual partners, social contacts, and health workers. Participants characterized stigma and discomfort with disclosure as normative, pervasive, and detrimental influences on health-seeking behavior both during sex and within healthcare interactions. Omission of information appears to be a particularly salient determinant of sexual behavior, inhibiting prevention of harm, like pain, and leading to adverse health outcomes. The development of measures of anal sex stigma and related sexual concerns, and testing their impact on comfort with disclosure, sexual practices, and engagement in health services could identify modifiable social pathways that contribute to health disparities among MSM, like those seen in the HIV epidemic.

Does per-act HIV-1 transmission risk through anal sex vary by gender? An updated systematic review and meta-analysis

Quantifying HIV-1 transmission risk per-act of anal intercourse (AI) is important for HIV-1 prevention. We updated previous reviews by searching Medline and Embase to 02/2018. We derived pooled estimates of receptive AI (URAI) and insertive AI (UIAI) risk unprotected by condoms using random-effects models. Subgroup analyses were conducted by gender, study design, and whether antiretroviral treatment (ART) had been introduced by the time of the study. Two new relevant studies were identified, one of which met inclusion criteria, adding three new cohorts and increasing number of individuals/partnerships included from 1869 to 14 277. Four studies, all from high-income countries, were included. Pooled HIV-1 risk was higher for URAI (1.25%, 95% CI 0.55%-2.23%, N = 5, I²  = 87%) than UIAI (0.17%, 95 % CI 0.09%-0.26%, N = 3, I²  = 0%). The sole heterosexual URAI estimate (3.38%, 95% CI 1.85%-4.91%), from a study of 72 women published in a peer-reviewed journal, was significantly higher than the men-who-have-sex-with-men (MSM) pooled estimate (0.75%, 95% CI 0.56%-0.98%, N = 4, P < 0.0001) and higher than the only other heterosexual estimate identified (0.4%, 95% CI 0.08%-2.0%, based on 59 women, excluded for being a pre-2013 abstract). Pooled per-act URAI risk varied by study design (retrospective-partner studies: 2.56%, 95% CI 1.20%-4.42%, N = 2 (one MSM, one heterosexual); prospective studies: 0.71%, 95% CI 0.51%-0.93%, N = 3 MSM, P < 0.0001). URAI risk was lower for studies conducted in the ART era (0.75%, 95% CI 0.52%-1.03%) than pre-ART (1.67%, 95% CI 0.44%-3.67%) but not significantly so (P = 0.537). Prevention messages must emphasize that HIV-1 infectiousness through AI remains high, even in the ART era. Further studies, particularly among heterosexual populations and in resource-limited settings, are required to elucidate whether AI risk differs by gender, region and following population-level ART scale-up.

Acceptability of testing for anorectal sexually transmitted infections and self-collected anal swabs in female sex workers, men who have sex with men and transgender women in Papua New Guinea

BACKGROUND

Papua New Guinea (PNG) has some of the highest prevalence of urogenital sexually transmitted infections (STIs) in Pacific Asia, but to date, anorectal STI prevalence data do not exist, and diagnosis of anorectal STIs does not occur. The purpose of this study was to document the acceptability of anorectal STI testing and self-collection of anorectal swabs for testing among populations at risk of anorectal STIs, in advance of a large bio-behavioural survey during which this approach to specimen collection was planned among key populations in PNG.

METHODS

Four focus groups were conducted, collecting data from a purposive sample of 35 members of two civil society groups representing female sex workers, men who have sex with men and transgender women in Port Moresby and Goroka.

RESULTS

All participants were in favour of anorectal STI testing in PNG. Reasons given for willingness to undertake anorectal STI testing included that anal sex is practised; that anorectal STIs are not perceived to exist; there are self-reported experiences of anorectal symptoms indicative of anorectal STIs; that anorectal STI testing will enhance personal health; and that anorectal STI testing is not currently available in PNG. All participants were confident they could obtain self-collected specimens, although several stated that support from trained health workers should be available for community members who may not feel comfortable with self-collection.

CONCLUSIONS

This qualitative research is the first study of acceptability of anorectal STI testing and specimen self-collection procedures in PNG, and Pacific Asia more broadly. Our qualitative findings show support for anorectal STI testing including the use of self-collected swabs among key populations in PNG. Study findings informed the inclusion of anorectal STI testing in a large bio-behavioural survey to be used to estimate anorectal STI prevalence among key populations in PNG for the first time.

Risk factors for HIV infection among female sex workers in Bangui, Central African Republic

Objective

The aims of the study were i) to categorize female sex workers (FSW) according to socio-anthropologic criteria in Bangui; ii) to examine the association between a selection of demographic and risk variables with the different categories of female sex work as outcome, and iii) to investigate factors associated with HIV status.

Methods

A cross-sectional questionnaire survey was conducted to describe the spectrum of commercial sex work in Bangui among 345 sexually active women. After collection of social and behavioral characteristics, each woman received a physical examination and a blood sample was taken for biological analyses, including HIV testing. The relationships between sociodemographic characteristics, behavioral variables involved in high risk for HIV as well as biological results were investigated by bivariate analysis in relationship with FSW categories as main outcomes, and by bivariate analysis followed by multivariate logistic regression analysis in relationship with HIV as the main outcome. The strength of statistical associations was measured by crude and adjusted Odds ratios (OR) and their 95% confidence intervals.

Results

The typology of FSW comprised six different categories. Two groups were the “official” professional FSW primarily classified according to their locations of work [i) “kata“(18.55%) representing women working in poor neighborhoods of Bangui; ii) “pupulenge” (13.91%) working in hotels and night clubs to seek white men]. Four groups were “clandestine” nonprofessional FSW classified according to their reported main activity [i) “market and street vendors” (20.86%); ii) “schoolgirls or students” (19.13%) involved in occasional transactional sex (during holidays); iii) “housewives or unemployed women” (15.65%); iv) “civil servants” (11.88%) working as soldiers or in the public sector]. The overall prevalence of HIV-1 was 19.12% (66/345). HIV varied according to FSW categories. Thus, among professional FSW, the HIV prevalence was 6-fold higher in "kata" than "pupulenge" (39.13% versus 6.30%; P = 0.001). Among nonprofessional FSW, the "vendors" showed the highest HIV prevalence (31.91%), which was higher than in "students" (6.10%; P = 0.001), "civil servants" (9.83%; P = 0.005), and "housewives" (13.00%; P = 0.01). In bivariate analysis, the following variables showed statistically significant association with risk for HIV infection: nationality; age of first sexual intercourse; self-assessment of HIV risk; knowledge of HIV status; anal sex practice with last clients; irregular condom use in last week; consumption of alcohol; other psycho-active substances; past history of STIs; HBs Ag; HSV-2 and bacterial vaginosis. However, the variable “sex workers categories” dichotomized into professional versus nonprofessional FSW was no longer associated with HIV. In multivariate logistical regression analysis, HIV infection was strongly associated with nationality (15.65% versus 3.77%) [adjusted OR (aOR) 3.39: 95% CI:1.25–9.16, P<0.05]; age of first sexual intercourse (21.10% versus 14.00%) (aOR 2.13: 95% CI: 1.03–4.39, P<0.05); anal sex practice with last clients (43.40% versus 11.50%) (aOR 4.31: 95% CI:2.28–8.33, P<0.001); irregular condom use in past week (33.50% versus 3.00%) (aOR 5.49: 95% CI:1.89–15.98, P<0.001); alcohol consumption before sex (34.70% versus 7.80%) (aOR 2.69: 95% CI:1.22–4.96, P<0.05); past history of STIs (41.00% versus 10.80%) (aOR 2.46: 95% CI:1.22–4.97, P<0.05) and bacterial vaginosis (29.80% versus 4.29%) (aOR 6.36: 95% CI: 2.30–17.72, P<0.001).

Conclusion

Our observations highlight the high level of vulnerability for HIV acquisition of both poor professional “kata” and nonprofessional “street vendor” FSW categories. These categories should be particularly taken into account when designing specific prevention programs for STIs/HIV control purposes.

Human beta-defensins 2 and -3 cointernalize with human immunodeficiency virus via heparan sulfate proteoglycans and reduce infectivity of intracellular virions in tonsil epithelial cells

We previously showed that expression of the anti-HIV innate proteins human beta-defensin 2 (hBD2) and hBD3 in adult oral epithelial cells reduces HIV transepithelial transmission by inactivation of virus. However, fetal/infant oral epithelia lack beta-defensin expression, leading to transmission of HIV. The mechanisms of hBD2- and hBD3-mediated HIV inactivation in adult oral epithelial cells are poorly understood. Here we found that heparan sulfate proteoglycans (HSPGs) on the apical surfaces of epithelial cells facilitate simultaneous binding of hBDs and HIV gp120 to the cell surface. HSPG-facilitated binding of hBDs and HIV gp120 to the cell surface did not affect viral attachment. HBD2 or -3 cointernalized with virions in endosomes, formed oligomers, and reduced infectivity of HIV. The anti-HIV effect of combining hBD2 and hBD3 was substantially higher than that of the individual peptides. These findings advance our understanding of the mechanisms of anti-HIV resistance in adult oral epithelium.

HIV Epidemic in Asia: Implications for HIV Vaccine and Other Prevention Trials

An overall decrease of HIV prevalence is now observed in several key Asian countries due to effective prevention programs. The decrease in HIV prevalence and incidence may further improve with the scale-up of combination prevention interventions. The implementation of future prevention trials then faces important challenges. The opportunity to identify heterosexual populations at high risk such as female sex workers may rapidly wane. With unabating HIV epidemics among men who have sex with men (MSM) and transgender (TG) populations, an effective vaccine would likely be the only option to turn the epidemic. It is more likely that efficacy trials will occur among MSM and TG because their higher HIV incidence permits smaller and less costly trials. The constantly evolving patterns of HIV-1 diversity in the region suggest close monitoring of the molecular HIV epidemic in potential target populations for HIV vaccine efficacy trials. CRF01_AE remains predominant in southeast Asian countries and MSM populations in China. This relatively steady pattern is conducive to regional efficacy trials, and as efficacy warrants, to regional licensure. While vaccines inducing nonneutralizing antibodies have promise against HIV acquisition, vaccines designed to induce broadly neutralizing antibodies and cell-mediated immune responses of greater breadth and depth in the mucosal compartments should be considered for testing in MSM and TG. The rationale and design of efficacy trials of combination prevention modalities such as HIV vaccine and preexposure prophylaxis (PrEP) remain hypothetical, require high adherence to PrEP, are more costly, and present new regulatory challenges. The prioritization of prevention interventions should be driven by the HIV epidemic and decided by the country-specific health and regulatory authorities. Modeling the impact and cost-benefit may help this decision process.

Prevalence and Frequency of Heterosexual Anal Intercourse Among Young People: A Systematic Review and Meta-analysis

We aim to assess if heterosexual anal intercourse (AI) is commonly practiced and how frequently it is practiced by young people. We searched PubMed for articles published 1975 to July 2014 reporting data on the proportion of young people (mean age <25) practicing heterosexual AI (AI prevalence) and on number of AI acts (AI frequency). Stratified random-effects meta-analysis and meta-regression were used to produce summary estimates and assess the influence of participant and study characteristics on AI prevalence. Eighty-three and thirteen of the 136 included articles reported data on lifetime AI prevalence and monthly AI frequency, respectively. Estimates were heterogenous. Overall summary estimates of lifetime AI prevalence were 22 % (95 % confidence interval 20-24) among sexually active young people, with no statistically significant differences by gender, continent or age. Prevalence increased significantly with confidentiality of interview method and, among males and in Europe, by survey year. Prevalence did not significantly differ by recall period. An estimated 3-24 % of all reported sex acts were AI. Reported heterosexual AI is common but variable among young people worldwide. To fully understand its impact on STI spread, more and better quality data on frequency of unprotected AI, and trends over time are required.

How can we design better vaccines to prevent HIV infection in women?

The human immunodeficiency virus (HIV) burden in women continues to increase, and heterosexual contact is now the most common route of infection worldwide. Effective protection of women against HIV-1 infection may require a vaccine specifically targeting mucosal immune responses in the female genital tract (FGT). To achieve this goal, a much better understanding of the immunology of the FGT is needed. Here we review the architecture of the immune system of the FGT, recent studies of potential methods to achieve the goal of mucosal protection in women, including systemic-prime, mucosal-boost, FGT-tropic vectors and immune response altering adjuvants. Advances in other fields that enhance our understanding of female genital immune correlates and the interplay between hormonal and immunological systems may also help to achieve protection of women from HIV infection.

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.

Heterosexual anal sex among female sex workers in high HIV prevalence states of India: need for comprehensive intervention

INTRODUCTION

Role of vaginal sex in heterosexual transmission of HIV has been investigated but that of heterosexual anal sex (HAS) is not fully understood. This paper examines practice of HAS among Female Sex Workers (FSWs) and its correlates in India where the HIV epidemic is being primarily driven by core groups like FSWs.

METHODS

Data for this paper are drawn from Round I survey of 9667 FSWs in the Integrated Biological and Behavioral Assessment (IBBA) from 23 districts of 4 high HIV prevalent states of India. Bivariate and multivariate analysis identified factors associated with HAS.

RESULTS

Ever having anal sex was reported by 11.9% FSWs (95% CI: 11.3%-12.6%). Typology (AOR 2.20, 95% CI 1.64-2.95) and literacy (AOR 1.28, 95% CI 1.10-1.49) were positively associated with practice of HAS. Longer duration in sex trade (AOR 1.69, 95% CI 1.44-1.99), entertaining larger number of clients the previous week (AOR 1.78, 95% CI 1.47-2.15), alcohol consumption (AOR 1.21, 95% CI 1.03-1.42) and inability to negotiate condom use (AOR 1.53, 95% CI 1.28-1.83) were also correlated with HAS. Self-risk perception for HIV (AOR 1.46, 95% CI 1.25-1.71) did not impede HAS. Although symptoms of sexually transmitted infections (STIs) in the last 12 months were associated with anal sex (AOR 1.39, 95% CI 1.13-1.72) there was no significant association between laboratory confirmed HIV and other STIs with HAS.

CONCLUSION

Practice of HAS by FSWs might significantly contribute to HIV transmission in India. This study also shows that despite self-risk perception for HIV, even literate FSWs with longer duration in sex work report HAS. General messages on condom use may not influence safe HAS. FSWs need to be targeted with specific messages on HIV transmission during anal sex. Women controlled prevention methods, such as rectal microbicides and vaginal microbicides are needed.

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.

Comprehensive assessment of HIV target cells in the distal human gut suggests increasing HIV susceptibility toward the anus

BACKGROUND

Prevention of rectal HIV transmission is a high-priority goal for vaccines and topical microbicides because a large fraction of HIV transmissions occurs rectally. Yet, little is known about the specific target-cell milieu in the human rectum other than inferences made from the colon.

METHODS

We conducted a comprehensive comparative in situ fluorescence study of HIV target cells (CCR5-expressing T cells, macrophages, and putative dendritic cells) at 4 and 30 cm proximal of the anal canal in 29 healthy individuals, using computerized analysis of digitized combination stains.

RESULTS

Most strikingly, we find that more than 3 times as many CD68 macrophages express the HIV coreceptor CCR5 in the rectum than in the colon (P = 0.0001), and as such rectal macrophages seem biologically closer to the HIV-susceptible CCR5 phenotype in the vagina than the mostly HIV-resistant CCR5 phenotype in the colon. Putative CD209 dendritic cells are generally enriched in the colon compared with the rectum (P = 0.0004), though their CCR5 expression levels are similar in both compartments. CD3 T-cell densities and CCR5 expression levels are comparable in the colon and rectum.

CONCLUSIONS

Our study establishes the target-cell environment for HIV infection in the human distal gut and demonstrates in general terms that the colon and rectum are immunologically distinct anatomical compartments. Greater expression of CCR5 on rectal macrophages suggests that the most distal sections of the gut may be especially vulnerable to HIV infection. Our findings also emphasize that caution should be exercised when extrapolating data obtained from colon tissues to the rectum.

Male sex workers who sell sex to men also engage in anal intercourse with women: evidence from Mombasa, Kenya

Objective

To investigate self-report of heterosexual anal intercourse among male sex workers who sell sex to men, and to identify the socio-demographic characteristics associated with practice of the behavior.

Design

Two cross-sectional surveys of male sex workers who sell sex to men in Mombasa, Kenya.

Methods

Male sex workers selling sex to men were invited to participate in surveys undertaken in 2006 and 2008. A structured questionnaire administered by trained interviewers was used to collect information on socio-demographic characteristics, sexual behaviors, HIV and STI knowledge, and health service usage. Data were analyzed through descriptive and inferential statistics. Bivariate logistic regression, after controlling for year of survey, was used to identify socio-demographic characteristics associated with heterosexual anal intercourse.

Results

From a sample of 867 male sex workers, 297 men had sex with a woman during the previous 30 days – of whom 45% did so with a female client and 86% with a non-paying female partner. Within these groups, 66% and 43% of male sex workers had anal intercourse with a female client and non-paying partner respectively. Factors associated with reporting recent heterosexual anal intercourse in bivariate logistic regression after controlling for year of survey participation were being Muslim, ever or currently married, living with wife only, living with a female partner only, living with more than one sexual partner, self-identifying as basha/king/bisexual, having one’s own children, and lower education.

Conclusions

We found unexpectedly high levels of self-reported anal sex with women by male sex workers, including selling sex to female clients as well as with their own partners. Further investigation among women in Mombasa is needed to understand heterosexual anal sex practices, and how HIV programming may respond.

Impact of Pill Sharing on Drug Resistance Due to a Wide-Scale Oral Prep Intervention in Generalized Epidemics

BACKGROUND

The first antiretroviral drug (Truvada) to be used as a pre-exposure prophylaxis (PrEP) in preventing HIV transmission is about to be approved. Behavioral studies suggest that a portion of users may share anti-retroviral drugs with sex partners, family, or friends. Pill sharing will decrease PrEP efficacy and adherence level, and potentially create an environment favorable for the development of drug resistance. We aim to evaluate the potential impact of pill sharing on the PrEP effectiveness and on the rates of drug-resistance development in heterosexual populations.

METHODS

A transmission dynamic model was used to assess the population-level impact of oral PrEP. The fractions of new HIV infections prevented (CPF), drug resistance prevalence and the proportion of new infections in which drug-resistant HIV is transmitted (TDR) are evaluated over fixed time periods. The influence of different factors on CPF and TDR is studied through simulations, using epidemic parameters representative of the countries in Sub-Saharan Africa.

RESULTS

Without pill sharing, a 70% efficacious PrEP used consistently by 60% of uninfected individuals prevents 52.8% (95% CI 49.4%-56.4%) of all new HIV infections over ten years with drug-resistant HIV transmitted in 2.2% of the new infections. Absolute CPF may vary by 9% if up to 20% of the users share PrEP while the level of TDR and total resistance prevalence may increase by up to 6-fold due to pill sharing in some intervention scenarios.

CONCLUSION

Pill sharing may increase the PrEP coverage level achieved in the population but it also affects the PrEP efficacy for the users who do not follow the prescribed schedule. More importantly, it creates a pool of untracked users who remain unreached by the effort to avoid sub-optimal PrEP usage by infected people. This increases substantially the potential risk of drug resistance in the population.

Vulnerability re-assessed: the changing face of sex work in Guntur district, Andhra Pradesh

We conducted a qualitative study to examine the impact of an HIV prevention programme on female sex workers' lives in Guntur district, Andhra Pradesh. The study found evidence that, in addition to the HIV prevention programme, structural and environmental factors had recently changed the way sex work was being practiced. Recent closure of the brothels and implementation of a late-night street curfew by the police meant sex work had become more hidden, with clients often solicited using mobile phones from home or their work place (e.g., in the fields or factories). Sex work had become safer, with violence by non-regular partners rarely reported. Women understood the risks of unprotected vaginal sex and reported using condoms with their clients. However, clients were more frequently requesting anal sex, possibly due to recent exposure to pornography following increased accessibility to modern technologies such as mobile phones and the Internet. Anal sex with clients was common but women were often unaware of the associated risks and reported unprotected anal sex. HIV positive and/or older women faced severe financial hardship and difficulty soliciting sufficient clients, and reported unprotected vaginal and anal sex to earn enough to survive. Taken together, the findings from this study suggest changing vulnerability to HIV in this setting. It will be important for HIV prevention programmes to be flexible and creative in their approaches if they are to continue to reach this target community effectively.

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.

Exploring dynamics of anal sex among female sex workers in Andhra Pradesh

OBJECTIVE

The anal sex among heterosexual couples is on the rise as reported in many scientific studies. Considering that unprotected anal sex has higher risk of human immunodeficiency virus (HIV) transmission than the vaginal sex, we undertook a study to understand the anal sex practices among Female Sex Workers (FSW).

MATERIALS AND METHODS

The study was conducted among FSW attending 11 randomly selected sexually transmitted infection (STI) clinics in Bill and Melinda Gates supported targeted interventions in Andhra Pradesh. A structured questionnaire was administered to the 555 FSW attending these clinics by project clinic counselors. Informed consent was obtained from all the study participants.

RESULTS

Engaging in anal sex was self reported by 22% of sex workers, though demand from clients was reported to be much higher (40%). The reasons for anal sex practices included more money (61%), clout/influence of the client (45%), risk of losing client (27%), and forced sex (1.2%). Factors associated with anal sex were higher number of clients, higher duration of sex work, higher income, and older age group. Associated risks perceived by FSW were bleeding and injury to anal canal (98%) while only 28% associated it with higher HIV transmission risk. Reported Condom and lubricant use was about 88% and 39% respectively.

CONCLUSION

The study shows that there is frequent anal sex, inconsistent condom and infrequent lubricant usage, economic and physical coercion, and low awareness of STI/HIV transmission risk among FSW, which have serious implications for HIV prevention programmes. There is a need to focus on anal sex education and use of lubricants along with condoms during anal sex in FSW-targeted interventions in AP.

Exploring dynamics of anal sex among female sex workers in Andhra Pradesh

OBJECTIVE

The anal sex among heterosexual couples is on the rise as reported in many scientific studies. Considering that unprotected anal sex has higher risk of human immunodeficiency virus (HIV) transmission than the vaginal sex, we undertook a study to understand the anal sex practices among Female Sex Workers (FSW).

MATERIALS AND METHODS

The study was conducted among FSW attending 11 randomly selected sexually transmitted infection (STI) clinics in Bill and Melinda Gates supported targeted interventions in Andhra Pradesh. A structured questionnaire was administered to the 555 FSW attending these clinics by project clinic counselors. Informed consent was obtained from all the study participants.

RESULTS

Engaging in anal sex was self reported by 22% of sex workers, though demand from clients was reported to be much higher (40%). The reasons for anal sex practices included more money (61%), clout/influence of the client (45%), risk of losing client (27%), and forced sex (1.2%). Factors associated with anal sex were higher number of clients, higher duration of sex work, higher income, and older age group. Associated risks perceived by FSW were bleeding and injury to anal canal (98%) while only 28% associated it with higher HIV transmission risk. Reported Condom and lubricant use was about 88% and 39% respectively.

CONCLUSION

The study shows that there is frequent anal sex, inconsistent condom and infrequent lubricant usage, economic and physical coercion, and low awareness of STI/HIV transmission risk among FSW, which have serious implications for HIV prevention programmes. There is a need to focus on anal sex education and use of lubricants along with condoms during anal sex in FSW-targeted interventions in AP.

The future role of rectal and vaginal microbicides to prevent HIV infection in heterosexual populations: implications for product development and prevention

OBJECTIVES

To compare the potential impact of rectal (RMB), vaginal (VMB) and bi-compartment (RVMB) (applied vaginally and protective during vaginal and anal intercourse) microbicides to prevent HIV in various heterosexual populations. To understand when a RMB is as useful than a VMB for women practicing anal intercourse (AI).

METHODS

Mathematical model was used to assess the population-level impact (cumulative fraction of new HIV infections prevented (CFP)) of the three different microbicides in various intervention scenarios and prevalence settings. We derived the break-even RMB efficacy required to reduce a female's cumulative risk of HIV infection by the same amount than a VMB.

RESULTS

Under optimistic coverage (fast roll-out, 100% uptake), a 50% efficacious VMB used in 75% of sex acts in population without AI may prevent ∼33% (27, 42%) new total (men and women combined) HIV infections over 25 years. The 25-year CFP reduces to ∼25% (20, 32%) and 17% (13, 23%) if uptake decreases to 75% and 50%, respectively. Similar loss of impact (by 25%-50%) is observed if the same VMB is introduced in populations with 5%-10% AI and for RR(RAI)=4-20. A RMB is as useful as a VMB (ie, break-even) in populations with 5% AI if RR(RAI)=20 and in populations with 15%-20% AI if RR(RAI)=4, independently of adherence as long as it is the same with both products. The 10-year CFP with a RVMB is twofold larger than for a VMB or RMB when AI=10% and RR(RAI)=10.

CONCLUSIONS

Even low AI frequency can compromise the impact of VMB interventions. RMB and RVMB will be important prevention tools for heterosexual populations.

Heterosexual anal intercourse and HIV infection risks in the context of alcohol serving venues, Cape Town, South Africa

Background

The most efficient sexual behavior for HIV transmission is unprotected receptive anal intercourse. However, it is unclear what role heterosexual unprotected anal sex is playing in the world's worst HIV epidemics of southern Africa. The objective is to examine the prevalence of heterosexual unprotected anal intercourse among men and women who drink at informal alcohol serving establishments (shebeens) in South Africa.

Methods

Cross-sectional surveys were collected from a convenience sample of 5037 patrons of 10 shebeens in a peri-urban township of Cape Town, South Africa. Analyses concentrated on establishing the rates of unprotected anal intercourse practiced by men and women as well as the factors associated with practicing anal intercourse.

Results

We found that 15% of men and 11% of women reported anal intercourse in the previous month, with 8% of men and 7% of women practicing any unprotected anal intercourse. Multiple logistic regression showed that younger age, having primary and casual sex partners, and meeting sex partners at shebeens were independently associated with engaging in anal intercourse. Mathematical modeling showed that individual risks are significantly impacted by anal intercourse but probably not to the degree needed to drive a generalized HIV epidemic.

Conclusions

Anal intercourse likely plays a significant role in HIV infections among a small minority of South Africans who patronize alcohol serving establishments. Heterosexual anal intercourse, the most risky sexual behavior for HIV transmission, should not be ignored in HIV prevention for South African heterosexuals. However, this relatively infrequent behavior should not become the focus of prevention efforts.

HIV transmission risk through anal intercourse: systematic review, meta-analysis and implications for HIV prevention

Background The human immunodeficiency virus (HIV) infectiousness of anal intercourse (AI) has not been systematically reviewed, despite its role driving HIV epidemics among men who have sex with men (MSM) and its potential contribution to heterosexual spread. We assessed the per-act and per-partner HIV transmission risk from AI exposure for heterosexuals and MSM and its implications for HIV prevention.

Methods Systematic review and meta-analysis of the literature on HIV-1 infectiousness through AI was conducted. PubMed was searched to September 2008. A binomial model explored the individual risk of HIV infection with and without highly active antiretroviral therapy (HAART).

Results A total of 62 643 titles were searched; four publications reporting per-act and 12 reporting per-partner transmission estimates were included. Overall, random effects model summary estimates were 1.4% [95% confidence interval (CI) 0.2–2.5)] and 40.4% (95% CI 6.0–74.9) for per-act and per-partner unprotected receptive AI (URAI), respectively. There was no significant difference between per-act risks of URAI for heterosexuals and MSM. Per-partner unprotected insertive AI (UIAI) and combined URAI–UIAI risk were 21.7% (95% CI 0.2–43.3) and 39.9% (95% CI 22.5–57.4), respectively, with no available per-act estimates. Per-partner combined URAI–UIAI summary estimates, which adjusted for additional exposures other than AI with a ‘main’ partner [7.9% (95% CI 1.2–14.5)], were lower than crude (unadjusted) estimates [48.1% (95% CI 35.3–60.8)]. Our modelling demonstrated that it would require unreasonably low numbers of AI HIV exposures per partnership to reconcile the summary per-act and per-partner estimates, suggesting considerable variability in AI infectiousness between and within partnerships over time. AI may substantially increase HIV transmission risk even if the infected partner is receiving HAART; however, predictions are highly sensitive to infectiousness assumptions based on viral load.

Conclusions Unprotected AI is a high-risk practice for HIV transmission, probably with substantial variation in infectiousness. The significant heterogeneity between infectiousness estimates means that pooled AI HIV transmission probabilities should be used with caution. Recent reported rises in AI among heterosexuals suggest a greater understanding of the role AI plays in heterosexual sex lives may be increasingly important for HIV prevention.