Iryna Zablotska

Unprotected anal intercourse, risk reduction behaviours, and subsequent HIV infection in a cohort of homosexual men

Objective:A range of risk reduction behaviours in which homosexual men practise unprotected anal intercourse (UAI) has been described. We aimed to assess the extent of any reduction in HIV risk associated with these behaviours. Design:A prospective cohort study of HIV-negative homosexual men in Sydney, Australia. Methods:Men were followed up with 6-monthly detailed behavioural interviews and annual testing for HIV. The four risk reduction behaviours (behaviourally defined) examined were serosorting, negotiated safety, strategic positioning, and withdrawal during receptive UAI (UAI-R). Results:In 88% of follow-up periods in which UAI was reported, it occurred in the context of consistent risk reduction behaviours. Compared with those who reported no UAI, the risk of HIV infection was not raised in negotiated safety [hazard ratio = 1.67, 95% confidence interval (CI) 0.59–4.76] and strategic positioning (hazard ratio = 1.54, 95% CI 0.45–5.26). Serosorting outside negotiated safety was associated with an intermediate rate of HIV infection (hazard ratio = 3.11, 95% CI 1.09–8.88). Withdrawal was associated with a higher risk than no UAI (hazard ratio = 5.00, 95% CI 1.94–12.92). Patterns of UAI differed greatly according to partners serostatus. Men who reported serosorting were less likely to report either strategic positioning or withdrawal. Conclusion:Each behaviour examined was associated with an intermediate HIV incidence between the lowest and highest risk sexual behaviours. The inverse association between individual behaviours suggests that men who practise serosorting rely on this protection. The high prevalence of these behaviours demands that researchers address the contexts and risks associated with specific types of UAI.

Per-contact probability of HIV transmission in homosexual men in Sydney in the era of HAART.

Objective:The objective of this study is to estimate per-contact probability of HIV transmission in homosexual men due to unprotected anal intercourse (UAI) in the era of HAART. Design:Data were collected from a longitudinal cohort study of community-based HIV-negative homosexual men in Sydney, Australia. Methods:A total of 1427 participants were recruited from June 2001 to December 2004. They were followed up with 6-monthly detailed behavioral interviews and annual testing for HIV till June 2007. Data were used in a bootstrapping method, coupled with a statistical analysis that optimized a likelihood function for estimating the per-exposure risks of HIV transmission due to various forms of UAI. Results:During the study, 53 HIV seroconversion cases were identified. The estimated per-contact probability of HIV transmission for receptive UAI was 1.43% [95% confidence interval (CI) 0.48–2.85] if ejaculation occurred inside the rectum, and it was 0.65% (95% CI 0.15–1.53) if withdrawal prior to ejaculation was involved. The estimated transmission rate for insertive UAI in participants who were circumcised was 0.11% (95% CI 0.02–0.24), and it was 0.62% (95% CI 0.07–1.68) in uncircumcised men. Thus, receptive UAI with ejaculation was found to be approximately twice as risky as receptive UAI with withdrawal or insertive UAI for uncircumcised men and over 10 times as risky as insertive UAI for circumcised men. Conclusion:Despite the fact that a high proportion of HIV-infected men are on antiretroviral treatment and have undetectable viral load, the per-contact probability of HIV transmission due to UAI is similar to estimates reported from developed country settings in the pre-HAART era.

Alcohol use before sex and HIV acquisition: a longitudinal study in Rakai, Uganda.

Objective:To examine the association between alcohol use and HIV acquisition. Design and methods:We examined alcohol use before sex and incident HIV in a population-based cohort in Rakai, Uganda, between 1994 and 2002. Adjusted incidence rate ratios (adjIRR) of HIV acquisition and 95% confidence intervals (CI) were estimated by Poisson multivariate regression. We also estimated adjusted prevalence rate ratios to assess the association between alcohol use and the number of sex partners and consistency of condom use. Results:In 6791 men and 8084 women HIV incidence was 1.4 per 100 person-years and 1.5 per 100 person-years, respectively. After adjustment for sociodemographic and behavioral factors, the risks of HIV when one partner consumed alcohol before sex were: adjIRR 1.67, 95% CI 1.17–2.40 among men, and adjIRR 1.40, 95% CI 1.02–1.92 among women, and when both partners consumed alcohol the risks were adjIRR 1.58, 95% CI 1.13–2.21 among men, and adjIRR 1.81, 95% CI 1.34–2.45 among women. Alcohol use was significantly associated with inconsistent condom use and multiple sexual partners in both sexes. Conclusion:The use of alcohol before sex increases HIV acquisition. A reduction of alcohol use should be incorporated into HIV prevention programmes.

Gay men's current practice of HIV seroconcordant unprotected anal intercourse: serosorting or seroguessing?

Abstract We explored seroguessing (serosorting based on the assumption of HIV seroconcordance) and casual unprotected anal intercourse (UAIC) associated with seroguessing. The ongoing Positive Health and Health in Men cohorts, Australia, provided data for trends in seroconcordant UAIC and HIV disclosure to sex partners. In event-level analyses, we used log-binomial regression adjusted for within-individual correlation and estimated prevalence rate ratios (PRRs) and 95% confidence intervals (95% CIs) for the association between the knowledge of a casual partners seroconcordance and UAIC. UAIC and HIV disclosure significantly increased during 2001–2006. HIV-positive men knew partners were seroconcordant in 54% and assumed it in 13% of sex encounters (42 and 17% among HIV-negative men). Among HIV-positive men, the likelihood of UAIC was higher when a partners status was known (Adjusted PRR = 5.17, 95% CI: 3.82–7.01) and assumed seroconcordant because of seroguessing (Adjusted PRR = 3.70, 95% CI: 2.56–5.35) compared with unknown. Among HIV-negative men, the likelihood of UAIC was also higher when a partners status was known (Adjusted PRR = 1.88, 95% CI: 1.58–2.24) and assumed seroconcordant (Adjusted PRR = 2.12, 95% CI: 1.72–2.62) compared with unknown. As levels of UAIC remain high, seroguessing increasingly exposes gay men to the risk of HIV infection. Because both HIV-positive and HIV-negative men often seroguess, education and prevention programs should address the fact that HIV-negative men who engage in UAI due to this practice may be at high risk of HIV infection. HIV prevention should take into account these contemporary changes in behaviors, especially among HIV-negative gay men.

Estimating levels of HIV testing, HIV prevention coverage, HIV knowledge, and condom use among men who have sex with men (MSM) in low-income and middle-income countries.

Background:HIV prevalence data suggest that men who have sex with men (MSM) in low-income and middle-income countries (LMIC) are at increased risk of HIV. The aim of this article is to present global estimates on key HIV prevention needs and responses among MSM in LMIC. Methods:Data on HIV testing, HIV prevention coverage, HIV knowledge and condom use among MSM were derived from UNGASS country progress reports submitted in 2008. Eligible country estimates were used to calculate global and regional estimates, weighted for the size of MSM populations. Results:Of 147 LMIC, 45% reported at least 1 indicator that reflects the HIV prevention needs and responses in MSM. Global weighted estimates indicate that on average 31% of MSM in LMIC were tested for HIV; 33% were reached by HIV prevention programs; 44% had correct HIV knowledge; and 54% used condoms the last time they had anal sex with a man. Conclusions:The 2008 UNGASS country reports represent the largest harmonized data set to date of HIV prevention needs and responses among MSM in LMIC. Although reporting is incomplete and does not always conform to requirements, findings confirm that, in many LMIC, HIV prevention responses in MSM need substantial strengthening.

Homosexual men in Australia: population, distribution and HIV prevalence.

OBJECTIVES To assess the size, distribution and changes in the population of homosexual and bisexual men in Australia, and the capacity of available measures to make this estimation. METHODS We used data from five sources: the Australian Study of Health and Relationships, the Gay Community Periodic Surveys, HIV Futures, the Health in Men cohort study, the Australian National HIV and AIDS Registries and the Australian Household Census. RESULTS We estimated that in 2001 there were approximately 74 000 homosexual and bisexual men in New South Wales (NSW), approximately 42 000 in Victoria and approximately 37 000 in Queensland. There was, however, some discrepancy between datasets in the estimates of the overall proportions and distribution of homosexual and bisexual men across states. We also estimated HIV prevalence rates among homosexual and bisexual men in 2001 at approximately 8% in NSW, 5% in Victoria and 4% in Queensland. There were insufficient data to estimate whether the state-specific populations of homosexual men were changing with time. CONCLUSION There are ~75% more homosexual and bisexual men in NSW than in Victoria and about twice as many as in Queensland. There are about two-thirds as many HIV-positive men in NSW as in Victoria and Queensland combined. Improved collection of population-based data on homosexuality are required.

Prevalence, incidence and risk factors for hepatitis C in homosexual men: data from two cohorts of HIV-negative and HIV-positive men in Sydney, Australia.

Background An increasing incidence of hepatitis C virus (HCV) infection in HIV-positive homosexual men has recently been described, but it is uncertain to what extent this reflects sexual transmission. We report prevalence, incidence and risk factors for HCV infection in community-based cohorts of HIV-negative and HIV-positive homosexual men in Sydney. Methods Both cohorts recruited participants using similar community-based strategies. Men underwent annual face-to-face interviews, and reported history of injecting-drug use (IDU) and sexual and other behaviours that might lead to blood contact. HCV screening was offered to consenting participants from 2001 to 2007. Results At baseline, HCV prevalence was 1.07% in the HIV-negative and 9.39% in the HIV-positive men. HCV seropositivity was strongly associated with a history of IDU in both cohorts (OR=56.18, 95% CI 12.55 to 251.5 in HIV-negative, and OR=24.46, 95% CI 5.44 to 110.0 in HIV-positive). In the HIV-negative cohort, five men seroconverted to HCV over 4412.1 person-years of follow-up, an incidence of 0.11 per 100 person-years (95% CI 0.03 to 0.26). Only one seroconverter reported IDU. Of the five, four reported sexual contact with HIV-positive men (HR=8.23, 95% CI 0.91 to 74.28), and two had an incident ulcerative sexually transmitted infection. In the HIV-positive cohort, none seroconverted over 238.1 person-years of follow-up (97.5% CI 0 to 1.54, single-sided). Conclusion HCV prevalence was almost 10 times higher in HIV-positive homosexual men. Although incident HCV infection was uncommon in both cohorts, cases of non-IDU-related transmission did occur, possibly linked to sexual contact with HIV-positive men.

High rates of sexually transmitted infections in HIV positive homosexual men: data from two community based cohorts

Background/objectives: Higher levels of sexual risk behaviours have been reported in HIV positive than in HIV negative homosexual men. In clinic based studies, higher rates of sexually transmitted infections (STIs) have also been reported. We compared rates of common STIs between HIV positive and HIV negative homosexual men from two ongoing community based cohort studies in Sydney, Australia. Methods: Participants in the two cohorts were recruited using similar community based strategies. They were interviewed face to face annually after enrolment. Comprehensive sexual health screening, including hepatitis A and B, syphilis, gonorrhoea, and chlamydia (in urethra and anus) was offered to participants in both cohorts. Results: In participants in the HIV positive cohort, 75% were hepatitis A seropositive, 56% had serological evidence of previous or current hepatitis B infection, and 24% had evidence of vaccination against hepatitis B infection. 19% of men tested positive for syphilis and 4% had evidence of recent infections. Compared with men in the HIV negative cohort, after adjustment for age, HIV positive participants had significantly higher prevalence of previous or current hepatitis B infection, syphilis, and anal gonorrhoea. Conclusion: This finding supports the need for frequent STI testing in HIV positive men to prevent morbidity and to decrease the risk of ongoing HIV transmission.

Changes in gay men's participation in gay community life: implications for HIV surveillance and research.

Successful antiretroviral treatments, achievements in gay acceptance and human rights, and internet use have prompted changes in gay socialising which create potential challenges for engaging with gay men for HIV surveillance and research. We used data from the Australian behavioural surveillance and explored (i) the relationship between community engagement and HIV related practices, and (ii) time trends in gay men’s engagement with the gay community. Analyses were conducted using log-binomial regression and chi-square test for trend. The proportion of men who socialized mainly with gay men declined and the Internet use to connect with sex partners increased over time. Gay social engagement was associated with HIV positive serostatus, unprotected anal intercourse with regular partners and a high frequency of HIV/STI testing. Our findings indicate a shift in how gay men socialise and find partners. We discuss the challenges for ongoing engagement with gay men for behavioural surveillance and HIV research.

Anal human papillomavirus genotype diversity and co-infection in a community-based sample of homosexual men

Objectives: To determine the prevalence and risk factors for anal human papillomavirus (HPV) infection in community-based cohorts of homosexual men in Sydney, Australia. Methods: A cross-sectional study in consecutively presenting participants in the positive Health and Health in Men cohorts in 2005. HPV testing was performed on anal PreservCyt specimens collected from 316 homosexual men (193 HIV-negative, 123 HIV-positive) using the Digene Hybrid Capture 2 (HC-2) assay for detection of low-risk (LR) and high-risk (HR) genotypes. HPV genotype testing was also performed on a subset of 133 men (93 HIV-negative, 36 HIV-positive) using Roche Linear Array (LA) assay. Results: HC-2 detected HPV infection in 79% of men (LR 55%, HR 69%). HIV-positive men were more likely than HIV-negative men to have LR-HPV (OR 3.5, 95% CI 2.1 to 5.7) and HR-HPV (OR 5.5, 95% CI 3.0 to 10.2). LA detected HPV infection in 95% of men (LR 85%, HR 77%). HIV-positive men had a mean of 7.1 HPV types compared to 4.2 in HIV-negative men; the difference was significant for both LR-HPV (p<0.001) and HR-HPV (p<0.001). HPV-16 was detected in 36% of HIV-positive and 27% of HIV-negative men. There was no consistent trend in HPV prevalence with increasing age. HR-HPV detection was associated with anal bleeding for HIV-positive men and anal warts for HIV-negative men. Conclusions: Anal HPV infection was nearly universal in this community-based sample of homosexual men. A wide variety of HPV genotypes were detected, and co-infection with multiple genotypes was common. Anal HPV infection is more prevalent and more diverse in HIV-positive than HIV-negative homosexual men.