[Analysis on voluntary blood donation and associated factors in men who have sex with men in 3 cities in China]

Objective: To assess the prevalence of blood donation and associated factors in men who have sex with men (MSM) in China. Methods: Our observational study was conducted between January and August, 2017 in 3 cities: Guangzhou, Shenzhen and Wuxi. Eligible participants were MSM (≥18 years old) who had either ≥2 male sex partners or unprotected anal sex with casual partners, or had been diagnosed with STI in the past 6 months. A self-completed tablet-based questionnaire was used to collect the information about MSM's socio-demographic characteristics, sexual behaviors and blood donation history. Results: A total of 603 MSM were enrolled in our study, including 302 in Guangzhou, 152 in Shenzhen and 149 in Wuxi, with a mean age of 27.9 years (SD=7.8). Overall, 29.2% (176/603) of the MSM reported a history of blood donation, and 33.1% (100/302)in Guangzhou, 27.6% (42/152) in Shenzhen and 22.8% (34/149) in Wuxi, the differences were not significant (χ(2)=6.421, P=0.093). Multivariate logistic regression analysis indicated that MSM had ever tested for HIV for ≥2 times in the past 12 months (vs. MSM tested for HIV one time, aOR=1.49, 95%CI: 1.08-2.19) or who had ever used gay dating app (vs. MSM who not used gay dating app, aOR=2.13, 95%CI: 1.12-4.44) were more likely to donate blood. Conclusions: Blood donation was common in MSM in China. Health education about blood donation in MSM should be strengthened to ensure the blood safety.

The extent of B-cell activation and dysfunction preceding lymphoma development in HIV-positive people

OBJECTIVES

B-cell dysfunction and activation are thought to contribute to lymphoma development in HIV-positive people; however, the mechanisms are not well understood. We investigated levels of several markers of B-cell dysfunction [free light chain (FLC)-κ, FLC-λ, immunoglobulin G (IgG), IgA, IgM and IgD] prior to lymphoma diagnosis in HIV-positive people.

METHODS

A nested matched case-control study was carried out within the EuroSIDA cohort, including 73 HIV-positive people with lymphoma and 143 HIV-positive lymphoma-free controls. Markers of B-cell dysfunction were measured in prospectively stored serial plasma samples collected before the diagnosis of lymphoma (or selection date in controls). Marker levels ≤ 2 and > 2 years prior to diagnosis were investigated.

RESULTS

Two-fold higher levels of FLC-κ [odds ratio (OR) 1.84; 95% confidence interval (CI) 1.19, 2.84], FLC-λ (OR 2.15; 95% CI 1.34, 3.46), IgG (OR 3.05; 95% CI 1.41, 6.59) and IgM (OR 1.46; 95% CI 1.01, 2.11) were associated with increased risk of lymphoma > 2 years prior to diagnosis, but not ≤ 2 years prior. Despite significant associations > 2 years prior to diagnosis, the predictive accuracy of each marker was poor, with FLC-λ emerging as the strongest candidate with a c-statistic of 0.67 (95% CI 0.58, 0.76).

CONCLUSIONS

FLC-κ, FLC-λ and IgG levels were higher > 2 years before lymphoma diagnosis, suggesting that B-cell dysfunction occurs many years prior to lymphoma development. However, the predictive value of each marker was low and they are unlikely candidates for risk assessment for targeted intervention.

A longitudinal cohort study of HIV 'treatment as prevention' in gay, bisexual and other men who have sex with men: the Treatment with Antiretrovirals and their Impact on Positive And Negative men (TAIPAN) study protocol

BACKGROUND

Australia has increased coverage of antiretroviral treatment (ART) over the past decade, reaching 73% uptake in 2014. While ART reduces AIDS-related deaths, accumulating evidence suggests that it could also bolster prevention efforts by reducing the risk of HIV transmission ('treatment as prevention'). While promising, evidence of community-level impact of treatment as prevention on reducing HIV incidence among gay and bisexual men is limited. We describe a study protocol that aims to determine if scale up of testing and treatment for HIV leads to a reduction in community viraemia and, in turn, if this reduction is temporally associated with a reduction in HIV incidence among gay and bisexual men in Australia's two most populous states.

METHODS

Over the period 2009 to 2017, we will establish two cohorts making use of clinical and laboratory data electronically extracted retrospectively and prospectively from 73 health services and laboratories in the states of New South Wales and Victoria. The 'positive cohort' will consist of approximately 13,000 gay and bisexual men (>90% of all people living with HIV). The 'negative cohort' will consist of at least 40,000 HIV-negative gay and bisexual men (approximately half of the total population). Within the negative cohort we will use standard repeat-testing methods to calculate annual HIV incidence. Community prevalence of viraemia will be defined as the proportion of men with a viral load ≥200RNA copies/mm³, which will combine viral load data from the positive cohort and viraemia estimates among those with an undiagnosed HIV infection. Using regression analyses and adjusting for behavioural and demographic factors associated with infection, we will assess the temporal association between the community prevalence of viraemia and the incidence of HIV infection. Further analyses will make use of these cohorts to assess incidence and predictors of treatment initiation, repeat HIV testing, and viral suppression.

DISCUSSION

This study will provide important information on whether 'treatment as prevention' is associated with a reduction in HIV incidence at a community level among gay and bisexual men.

Increasing realism among gay men in Sydney about HIV treatments: changes in attitudes over time

It is important to know if optimism about HIV treatments is widespread and whether it is growing. To this end, cross-sectional surveys of gay men were conducted 6-monthly in Sydney between February 1997 and February 1999 ( n = 3012). Recruitment was consistent at 4 gay community venues. The participants responded True, False or Unsure to 5 statements about the effectiveness of HIV treatments (2 items), and transmission (2 items) and 'worry' (1 item) in the context of treatments. In terms of effectiveness, HIV-positive men were more likely than non-positive men to dismiss 'cure' ( P < 0.05) and more likely to support 'treatments prevent serious illness' ( P < 0.001). Uncertainty about effectiveness decreased over time ( P < 0.001 for each item). In terms of transmission, HIV-positive men were more likely than non-positive men to reject notions of reduced infectivity ( P < 0.001). Over time, there was less uncertainty among non-positive men about undetectable viral load and transmission possibilities ( P < 0.001). Overall, HIV-positive men were less 'worried' than non-positive men ( P < 0.001) but there were no changes over time. On the whole, gay men in Sydney are now less uncertain about highly active antiretroviral therapies (HAART) than at the time of their introduction. Most men remain sceptical that these treatments can cure HIV infection and prevent HIV transmission, but in regard to managing illness among those infected, some initial uncertainty is being replaced by a growing optimism about the efficacy of treatments.

Protocol for an open-label, single-arm trial of HIV pre-exposure prophylaxis (PrEP) among people at high risk of HIV infection: the NSW Demonstration Project PRELUDE

INTRODUCTION

Despite a number of HIV prevention strategies, the number of new HIV infections remains high. In Australia, over three-quarters of new HIV diagnoses are in gay and bisexual men (GBM). Pre-exposure prophylaxis (PrEP) has been shown to be effective at preventing new HIV infections in several randomised trials. The PRELUDE study aims to evaluate the implementation of PrEP in healthcare settings in New South Wales (NSW), Australia, among a sample of high-risk adults.

METHODS AND ANALYSIS

PRELUDE is an ongoing open-label, single-arm demonstration project, conducted in public and private clinics across NSW, Australia. Enrolment began in November 2014. The study is designed for 300 high-risk participants-mainly GBM and heterosexual women. Participants receive daily oral PrEP, composed of emtricitabine (FTC) and tenofovir disoproxil fumarate (TDF), for up to 2.5 years. Quarterly study visits include testing for HIV and sexually transmitted infections (STIs), assessment of ongoing eligibility and side effects, and self-reported adherence. Following each study visit, online behavioural surveys are administered to collect information on medication adherence, risk behaviours and attitudes. Blood samples will be collected in a subset of patients 1, 6 and 12 months after PrEP initiation to measure FTC/TDF concentrations. Analyses using longitudinal regression models will focus on feasibility, adherence, safety, tolerability and effects of PrEP on behaviour. This study will inform PrEP policy and guide the implementation of PrEP in Australia in people at high risk of HIV.

ETHICS AND DISSEMINATION

The study will be conducted in accordance with the Declaration of Helsinki. All patients will provide written informed consent prior to participation in the study. Publications relating to each of the primary end points will be gradually released after 12 months of follow-up is complete.

TRIAL REGISTRATION NUMBER

NCT02206555; Pre-results.

Oral and anal sex are key to sustaining gonorrhoea at endemic levels in MSM populations: a mathematical model

OBJECTIVES

Despite early treatment of urethral infection, gonorrhoea is endemic in urban populations of men who have sex with men (MSM) in Australia. By contrast, gonorrhoea is not common in urban heterosexual populations. Sexual activities among MSM usually involve anal or oral sex, and as these behaviours are becoming increasingly common among heterosexuals, there is a need to investigate their roles in transmission of gonorrhoea.

METHODS

We developed individual-based models of transmission of gonorrhoea in MSM and heterosexuals that incorporate anatomical site-specific transmission of gonorrhoea. We estimated the probabilities of transmission for anal sex and oral sex by calibrating an MSM model against prevalence of gonorrhoea and sexual activity data. These probabilities were then applied to a heterosexual model in order to examine whether gonorrhoea can persist in a heterosexual population through the addition of anal sex and oral sex.

RESULTS

In the MSM model, gonorrhoea can persist despite prompt treatment of urethral infections. The probability of gonorrhoea persisting is reduced if use of condom for oral sex is increased to more than 15% of acts. Assuming that treatment of symptomatic infections is prompt, gonorrhoea is unlikely to persist in a heterosexual population even with the addition of anal and oral sex.

CONCLUSIONS

Our models suggest that oral sex has an important role in sustaining gonorrhoea in a population of MSM by providing a pool of untreated asymptomatic infection. The importance of anal sex or oral sex in sustaining gonorrhoea in a heterosexual population remains uncertain due to the lack of information linking different types of sex acts and transmissibility.

16. Prevalence and correlates of unsatisfactory anal pap tests (UAPT) in a community-recruited cohort of Australian homosexual men

Background Anal Pap tests have been advocated as a screening tool for anal precancerous lesions. We aimed to ascertain prevalence and correlates of UAPT among homosexual men. Methods: SPANC is a 3-year prospective study of homosexual men aged ≥35 years in Sydney. At baseline, data were collected and study procedures, including an anal swab for ThinPrep® cytology, were performed. Results: UAPT initially occurred in 40 (11.7%) of 342 participants (median age 49 years; 28.7% HIV positive) enrolled by the end of March 2013. There was no difference in UAPT by collecting clinician (P = 0.669) or reporting pathologist (P = 0.267). UAPT occurred more than twice as often among HIV-negative compared with -positive men (13.9% vs 6.1%, P = 0.048) and were less likely than satisfactory smears to contain transformation zone (TZ) cells (4.6% vs 35.4%, P < 0.001). Having a UAPT was associated with more anal Pap swab discomfort (P = 0.037) and feeling more tense during the exam (P = 0.008), but not with haemorrhoids or past anal surgery. On multivariate analysis, never douching (P < 0.001), soapy water douching (among those who douched; P = 0.003), fewer anal HPV types (P = 0.005) and feeling more tense during the exam (P = 0.039) remained independently associated with UAPT. All UAPT were repeated within a month and results were: 21 (52.5%) again unsatisfactory, 13 (32.5%) negative, 2 (5.0%) ASCUS/LSIL and 4 (10%) ASC-H/HSIL. Conclusions: UAPT are more common among men with less receptive anal sexual experience. Causes of UAPT may be a combination of sampling, behavioural and biological factors.

Head and neck cancer in Australia between 1982 and 2005 show increasing incidence of potentially HPV-associated oropharyngeal cancers

BACKGROUND

Although tobacco- and alcohol-associated head and neck cancers are declining in the developed world, potentially human papillomavirus (HPV)-associated oropharnygeal cancers are increasing.

METHODS

We analysed oropharyngeal and oral cavity cancer rates in Australia in 1982-2005. Cancers from the oropharynx (base of tongue, tonsil and other specific oropharyngeal sites) were classified as potentially HPV associated (n=8844); cancers in other oral cavity and oropharyngeal sites not previously associated with HPV were classified as comparison (n=28,379).

RESULTS

In 2000-2005, an average of 219, 159 and 110 cancers of the tonsil, base of tongue and other oropharyngeal sites were diagnosed annually, with incidences of 1.09 (95% CI: 1.03, 1.15), 0.79 (95% CI: 0.74, 0.84) and 0.55 (95% CI: 0.50, 0.59) per 100,000, respectively. An average of 1242 comparison cancers were diagnosed annually (6.17 (95% CI: 6.03, 6.31) per 100,000). In 1982-2005, there were significant annual increases in tonsil (1.39% (95% CI: 0.88, 1.92%)) and base of tongue cancers in males (3.02% (95% CI: 2.27, 3.78%)) and base of tongue cancer in females (3.45% (95% CI: 2.21, 4.70%)). There was a significant decrease in comparison cancers in men (-1.69% (95% CI: -1.96, -1.42%)), but not in females.

CONCLUSION

Potentially HPV-associated oropharyngeal cancer in Australia is increasing; the impact of HPV vaccination on these cancers should be monitored.

Contexts for last occasions of unprotected anal intercourse among HIV-negative gay men in Sydney: The health in men cohort

The objective of the paper was to compare encounters involving unprotected anal intercourse (UAI) and protected anal intercourse (PAI) among HIV-negative gay men in Sydney. Data were from those completing baseline face-to-face interviews to end June 2003 for the Health in Men open cohort of HIV-negative gay men in Sydney. The 1,148 participants ranged in age from 18 to 75 years (median = 36). Three hundred and fifty-two (30.7%) reported an occasion of UAI with a casual partner in the previous 6 months and 531 (46.3%) reported an occasion of UAI with a regular partner in that same time. The men's most recent sexual contact with a casual partner involving UAI was distinguished from those involving PAI by a greater likelihood for both partners to disclose HIV serostatus (p = 0.006) and by respondents being more inclined to restrict themselves to the insertive position or to practise withdrawal during occasions involving any UAI than when a condom was used (p = 0.003 and p = 0.001 respectively). Neither location nor recreational drug use differentiated men's most recent sexual contacts involving UAI from those involving PAI. The decision by HIV-negative gay men to use condoms during sexual encounters with either regular or casual partners is guided more by HIV serostatus and risk reduction strategies than by other factors.

Seroconversion in context

This paper describes the accounts that homosexually active men give of their HIV seroconversion and interrogates these accounts for risk discourses. In particular, this paper asks whether the risk discourses of HIV researchers and educators are present in the men's narratives of their own seroconversion. Such discourses make reference to 'unsafe' sex--particularly the practice of unprotected anal intercourse, numbers of sexual partners or 'promiscuity', and the disinhibiting effect of drugs and alcohol. The data are drawn from an ongoing case-series study of seroconversion in which men who had seroconverted were asked to give an account of the occasion on which they believe they were infected. A number of themes were identified in the men's accounts. The men's descriptions of what they believe to be the seroconversion event indicate that their attributions, i.e., the reasons they give for their HIV infection, vary depending on the context. Within regular relationships, breakdown of negotiated safety, love and intimacy, and fatalism were among the explanations given. Seroconversion attributed to casual sexual encounters was more likely to be explained in terms of pleasure, lack of control, and with reference to particular sexual settings. The ways in which men understood their HIV infection were informed both by the risk discourse of HIV researchers and also by the discourses of love and pleasure, as well as that of control.

Sex work and risk behaviour among HIV-negative gay men

Gay men who engage in sex work may be at increased risk through risk behaviour outside the context of sex work. Among participants in the Health in Men (HIM) cohort of HIV-seronegative gay men in Sydney, 19.7% had ever engaged in sex work. Five percent reported being paid for sex in a six-month period during the study (2001-2006); a minority (18.3%) of these current sex workers reported unprotected anal intercourse (UAI) with clients and 62.0% reported UAI with any casual partners. The practice of sex work itself may not represent increased risk for HIV transmission but sex workers in this study were, nonetheless, at markedly increased risk in other aspects of their lives.

Differences between HIV-positive gay men who 'frequently', 'sometimes' or 'never' engage in unprotected anal intercourse with serononconcordant casual partners: positive Health cohort, Australia

By measuring the actual number of risk acts engaged in by HIV-positive men participating in the Positive Health (PH) cohort study, this paper sets out to document the distribution of risk acts, to report on the proportion of acts of unprotected anal intercourse with casual (UAIC) partners that occurred between HIV-positive men (i.e. seroconcordant positive) and to examine the factors that differentiated men who 'frequently' compared with 'sometimes' or 'never' engaged in unsafe UAIC (i.e. UAIC with serononconcordant partners: partners who have not tested positive for HIV). The findings show that 42.6% of all UAIC acts occurred between seroconcordant HIV-positive partners, posing no risk of HIV infection to an HIV-negative person. A minority of participants (10%) accounted for the majority (70.7%) of the unsafe acts of UAIC. The HIV-positive men who 'sometimes' engaged in unsafe UAIC had higher treatment optimism scores and were more likely to use Viagra in comparison with those who did not engage in such risk. Those who reported 'frequent' engagement in unsafe UAIC were more likely to engage in a range of esoteric sexual practices, be slightly less well educated and be taking antiretroviral therapy compared with HIV-positive men who 'sometimes' engaged in unsafe UAIC. As such, taking ART but not viral load, predicted frequent unsafe UAIC. When considered alongside earlier studies, these results suggest that HIV-negative men who engage in esoteric sexual practices may be at increased risk of HIV transmission, not necessarily because they engage in esoteric sex practices but because of the sub-cultural milieu in which esoteric sex is occurring. The findings from this study also endorse the measurement of UAIC acts as a useful gauge of risk.

Differences between men who report frequent, occasional or no unprotected anal intercourse with casual partners among a cohort of HIV-seronegative gay men in Sydney, Australia

Past research on unprotected anal intercourse with casual partners (UAIC) contrasts those who report no UAIC with any UAIC. This paper examines differences among three groups of men who had any UAIC on the basis of the number of UAIC acts reported in a six-month period, namely no UAIC (n = 507), occasional UAIC (1-5 acts, n = 251) and frequent UAIC (more than 5 acts, n = 148). The occasional UAIC group had values lying between those of the no- and the frequent-UAIC group. As compared with the frequent-UAIC group, men in the occasional-UAIC group were less likely to have a steady partner, held less favorable attitudes toward condoms and higher levels of HIV treatments optimism and were more likely to report some disclosure of serostatus to or by casual partners and a range of esoteric sexual practice. On the other hand, men in the no-UAIC group had lower levels of 'feeling bad' (distress) and were less likely to use drugs to enhance sexual pleasure in casual encounters. Disclosure of serostatus had a strong association with frequent UAIC and this finding calls for both more research and more community exploration of issues surrounding sexual decision-making.

Trends and predictors of HIV-positive community attachment among PLWHA

Communities most affected by HIV/AIDS have been instrumental in shaping Australia's responses to the threat of the epidemic. There are recent signs that levels of engagement in communities based around HIV-positivity have changed: a diminished sense of an AIDS crisis, the relative success of highly active antiretroviral therapy (HAART), and an increasing individualization of the HIV experience may be contributing to changes in the way HIV-community is experienced. In this paper, we explore levels of engagement in HIV-positive community among a cohort of people living with HIV/AIDS (PLWHA) and seek to explain why some PLWHA engage in an HIV-positive community while others do not. Using multivariate logistic regression, we found that three factors were independently related to feeling part of an HIV-positive community: having been diagnosed with HIV prior to the advent of HAART; having more recently taken Bactrim or Septrin for PCP; and finding it easier to take 'pills' on time. Taken together, these results suggest that both historical effects, such as the introduction of HAART, and effects related to living with HIV, such as the experience of an AIDS-related illness, help explain HIV-positive community engagement among PLWHA.

64. DOES CIRCUMCISION MAKE A DIFFERENCE TO THE SEXUAL EXPERIENCE OF GAY MEN? FINDINGS FROM THE HEALTH IN MEN (HIM) COHORT

The relevance of circumcision in preventing HIV male-to-male sex transmission is poorly understood, in particular because any potential effect could be obscured by sexual practice as a mediating or confounding factor. Using data from the Health in Men (HIM) cohort of 1426 HIV-negative homosexually active men in Sydney, we compared the sexual practices and sexual experiences of circumcised and uncircumcised men. Overall 66% of men (n�=�939) in the cohort were circumcised. After adjusting for age and ethnicity, we found no difference between circumcised and uncircumcised men in anal sexual practices, difficulty using condoms, or sexual difficulties (e.g. loss of libido). Among the circumcised men, we compared those circumcised at infancy (n�=�854) with those circumcised after infancy (n�=�81). The majority cited phimosis (i.e., an inability to fully retract the foreskin) and parents' decision as the main reasons for circumcision after infancy. After adjusting for age and ethnicity, men circumcised after infancy were more likely to practise receptive anal sex (88% vs 75%, p�<�0.05) and to experience erection difficulties (52% vs 47%, p�<�0.05); but less likely to practise insertive anal sex (79% vs 87%, p�<�0.05) and to experience premature ejaculation (15% vs 23%, p�<�0.05) than those circumcised at infancy. Our data suggest that overall circumcision status does not affect HIV-negative gay men's anal sexual practices, experience of condom use or likelihood of sexual difficulties. However, there is some suggestion of differences between circumcised men depending on the age at circumcision.

27. CAN UNPROTECTED ANAL INTERCOURSE WITH REGULAR AND CASUAL PARTNERS EXPLAIN THE DIVERGING TRENDS IN HIV EPIDEMIC IN AUSTRALIA?

Introduction: Worldwide, increases in unprotected anal intercourse have been linked to the resurgence in HIV and STI in gay men. We assessed whether changes in UAI within regular and casual relationships may explain the diverging trends in HIV in three Australian states - NSW, Victoria and Queensland. Methods: We used the data from the annual cross-sectional Gay Community Periodic Surveys conducted annually in Sydney since 1996 and in Melbourne and Queensland since 1998. A short self-administered questionnaire asks about HIV serostatus, sexual health testing and behaviours relevant to HIV epidemic. We present time trends in seroconcordance and unprotected sex with regular and casual partners. Results: Currently, about one third of gay men report being in monogamous regular relationships, and this proportion has been slowly increasing everywhere. The self-reported UAI with regular partners (UAIR) was highest among men in seroconcordant positive relationships, lower among seroconcordant negative partners and lowest in non seroconcordant relationships. From 1998 to 2006, the rates of UAIR consistently increased by 10% in all three states and in all relationships by serostatus. The rates of UAI with casual partners (UAIC) were historically highest in NSW. From a peak in 2001, UAIC rates have consistently declined in NSW, but continuing increases were observed in Victoria and Queensland. Higher rates of nondisclosure of HIV were also observed in the context of UAIC in the latter two states. Conclusion: Changes in unprotected sex with casual partners may be responsible for the slowing of HIV epidemic in NSW. Sustained investment in policies and programs are important in achieving behaviour change.

30. TESTING FOR SEXUALLY TRANSMISSIBLE INFECTIONS AMONG GAY MEN IN SYDNEY, AUSTRALIA

Introduction: Recently, rates of sexually transmissible infections (STIs) have been increasing among gay men in Australia and elsewhere. We explored trends in STI testing among gay men in Sydney. Methods: We used behavioural data from the six-monthly Sydney Gay Community Periodic Survey (SGCPS). Men are recruited through gay community venues, clinics and events in Sydney. Since 2003 men were asked whether they had received the following tests in the previous year: Anal swab, throat swab, penile swab, urine sample, and blood test for STIs other than HIV. Men recruited from clinics were excluded from the following analyses. Results: In 2006, 3145 completed questionnaires were received from non-clinic sites, with 40.9% of respondents reporting having received an anal swab, 45.4% a throat swab, 34.6% a penile swab, 52.7% a urine sample, and 56.1% a blood test for STIs other than HIV. The majority (67.2%) reported at least one test for STIs, with 25.5% having received all five forms of STI test. Although there was no increase during 2003-2006 in having any STI tests, the proportion of men having received all five types of test increased. The largest increase was in the proportion reporting anal swabs: from 23.8% in 2003 to 40.9% in 2006. Among men reporting unprotected anal intercourse with casual partners (UAIC), as well as among men with more than ten casual partners in the previous six months, rates of STI testing were higher but the time trends were similar. Conclusion: The majority of men report STI testing in the previous year, and this testing has become more comprehensive, with men receiving a broader range of STI tests over time. Men at higher risk for STIs tested at increased rates.

28. RISK TAKING AND SAFER SEX PRACTICES IN CASUAL RELATIONSHIPS BETWEEN MEN

Introduction: Universal condom use in casual sex is unlikely. We explored whether gay men lower the risk of HIV transmission during unprotected anal intercourse with casual partners (UAIC) by disclosing HIV serostatus and engaging in lower risk practices such as strategic positioning and/or withdrawal. Methods: We used data from the annual cross-sectional Sydney Gay Community Periodic Survey. A short self-administered questionnaire collects information about HIV serostatus of the respondents, sexual practices with other men and other HIV-relevant behaviours. We present the prevalence of and time trends in disclosure of serostatus and the use of strategic positioning and withdrawal with casual partners. Results: In 2006, 2568 men reported having had a casual partner in the 6 months before the survey. Disclosure was higher among men engaging in UAIC (68.4%) compared to those who always used condoms (49.7%). This relationship was more apparent amongst HIV-positive than negative men, of whom 83.5% and 63.9%, respectively, reported any disclosure. Over time, HIV-positive and negative men have increasingly reported disclosing to 'all' of their casual partners (p�<�0.01). HIV-positive men were less likely to report insertive-only positioning during UAIC (8.9%) compared to HIV-negative men (39.2%), with no changes emerging since over time. Significant increases were also noted in the proportion of HIV-positive men reporting withdrawal during insertive-UAIC (p�<�0.001) and HIV-negative men reporting withdrawal during receptive-UAIC (p�<�0.001). Conclusion: In the context of UAIC, gay men appear to be employing a range of risk-reduction strategies. Increasing levels of disclosure and/or practices such as strategic positioning and withdrawal demonstrate the complexity of gay men's construction of, and engagement with, risk associated with HIV transmission. A more thorough understanding of these practices is essential for ongoing education and prevention.

Smoking and erectile dysfunction: findings from a representative sample of Australian men

OBJECTIVES

To examine whether there is an association between smoking and erectile dysfunction in a representative sample of Australian men.

DESIGN

Secondary analysis of cross-sectional survey data from the Australian Study of Health and Relationships.

PARTICIPANTS

8367 Australian men aged 16-59 years.

MAIN OUTCOME MEASURES

Erectile dysfunction was identified in men who reported having had trouble keeping an erection when they wanted to, a problem which persisted for at least one month over the previous year. Variables examined in multivariate logistic regression analyses included age, education, presence of cardiovascular disease and diabetes, and current alcohol and tobacco consumption.

RESULTS

Almost one in 10 of the respondents (9.1%) reported erectile dysfunction that lasted for at least one month over the previous year. More than a quarter (27.2%) of respondents were current smokers, with 20.9% smoking < or = 20 cigarettes per day, and 6.3% smoking > 20 cigarettes per day. Compared with non-smokers, the adjusted odds ratios for erectile dysfunction were 1.24 (95% confidence interval (CI) 1.01 to 1.52, p = 0.04) for those smoking < or = 20 cigarettes per day and 1.39 (95% CI 1.05 to 1.83, p = 0.02) for those smoking > 20 cigarettes per day, after adjusting for other confounding factors. Older age, low level of education, and taking medications for cardiovascular disease were also independently and positively associated with erectile dysfunction. In contrast, moderate alcohol consumption (1-4 drinks per day) significantly reduced the likelihood of having erectile dysfunction.

CONCLUSIONS

Erectile dysfunction is a significant health concern affecting around one in 10 Australian men aged 16-59 years. Current smoking is significantly associated with erectile dysfunction in Australian males. This association was strengthened as the number of cigarettes smoked increased. Health promotion programmes could use the link between smoking and erectile dysfunction to help reduce smoking levels among men.

Occupational exposure to power frequency magnetic fields and risk of non-Hodgkin lymphoma

OBJECTIVES

To investigate the risk of non-Hodgkin lymphoma (NHL) using a job-exposure matrix (JEM) to assess exposure to occupational magnetic fields at the power frequencies of 50/60 Hz.

METHODS

The study population consisted of 694 cases of NHL, first diagnosed between 1 January 2000 and 31 August 2001, and 694 controls from two regions in Australia, matched by age, sex and region of residence. A detailed occupational history was given by each subject. Exposure to power frequency magnetic fields was estimated using a population-based JEM which was specifically developed in the United States to assess occupational magnetic field exposure. The cumulative exposure distribution was divided into quartiles and adjusted odds ratios were calculated using the lowest quartile as the referent group.

RESULTS

For the total work history, the odds ratio (OR) for workers in the upper quartile of exposure was 1.48 (95% CI 1.02 to 2.16) compared to the referent (p value for trend was 0.006). When the exposure was lagged by 5 years the OR was 1.59 (95% CI 1.07 to 2.36) (p value for trend was 0.003). Adjusting for other occupational exposures did not significantly alter the results.

CONCLUSIONS

These findings provide weak support for the hypothesis that occupational exposure to 50/60 Hz magnetic fields increases the risk of NHL.

Is there a difference in the efficacy of peripartum antiretroviral regimens in reducing mother-to-child transmission of HIV in Africa?

BACKGROUND

Peripartum antiretroviral regimens have been shown to prevent mother-to-child transmission of HIV (MTCT) in randomized clinical trials; however, direct comparison of published results is impossible given methodological and population differences.

OBJECTIVE

To directly compare the efficacy of different antiretroviral regimens in reducing the risk of 6-week MTCT rate in African breastfeeding populations.

METHODS

Pooled analysis including all mother-infant pairs from any relevant trial: West African ZDV-placebo trials, Petra ZDV+3TC [two regimens A (pre/intra/post-partum) and B (intra/post-partum), placebo from Uganda and Tanzania], SAINT (NVP and Petra arm B), HIVNET012 (NVP, ultra short ZDV pp) and the Vitamin A trial (as placebo arm in South Africa). Peripartum HIV infection was any positive RNA or DNA polymerase chain reaction test < day 60. The MTCT risk was estimated at 6 weeks for each treatment arm and compared with placebo or single-dose NVP using logistic regression adjusting for maternal CD4 cell count, breastfeeding and birthweight.

RESULTS

Overall, 4125 singleton live-births were included; 3629 (88%) were assessed for HIV status at 6 weeks of age. In comparison with placebo, zidovudine + lamivudine (ZDV+3TC) arm A [adjusted odds ratio (AOR), 0.23; P < 0.0001], ZDV+3TC arm B (AOR, 0.49; P < 0.001), antenatal ZDV short (AOR, 0.55; P = 0.006) and nevirapine (NVP) (AOR, 0.60; P = 0.0007) significantly reduced MTCT. In comparison with NVP, only the longest regimen of ZDV+3TC (AOR, 0.39, P < 0.0005) was significantly more effective.

CONCLUSION

These results are in line with current World Health Organisation guidelines suggesting equivalence of choice between single-dose NVP and short-course ZDV, and confirm the greater efficacy of ZDV+3TC than with any single antiretroviral drug.

Occupational exposure to pesticides and risk of non-Hodgkin's lymphoma

Pesticide exposure may be a risk factor for non-Hodgkin's lymphoma, but it is not certain which types of pesticides are involved. A population-based case-control study was undertaken in 2000-2001 using detailed methods of assessing occupational pesticide exposure. Cases with incident non-Hodgkin's lymphoma in two Australian states (n = 694) and controls (n = 694) were chosen from Australian electoral rolls. Logistic regression was used to estimate the risks of non-Hodgkin's lymphoma associated with exposure to subgroups of pesticides after adjustment for age, sex, ethnic origin, and residence. Approximately 10% of cases and controls had incurred pesticide exposure. Substantial exposure to any pesticide was associated with a trebling of the risk of non-Hodgkin's lymphoma (odds ratio = 3.09, 95% confidence interval: 1.42, 6.70). Subjects with substantial exposure to organochlorines, organophosphates, and "other pesticides" (all other pesticides excluding herbicides) and herbicides other than phenoxy herbicides had similarly increased risks, although the increase was statistically significant only for "other pesticides." None of the exposure metrics (probability, level, frequency, duration, or years of exposure) were associated with non-Hodgkin's lymphoma. Analyses of the major World Health Organization subtypes of non-Hodgkin's lymphoma suggested a stronger effect for follicular lymphoma. These increases in risk of non-Hodgkin's lymphoma with substantial occupational pesticide exposure are consistent with previous work.

Use of the WHO lymphoma classification in a population-based epidemiological study

BACKGROUND

Non-Hodgkin's lymphoma (NHL) is pathologically diverse. Epidemiological investigations into its increasing incidence and aetiology require accurate subtype classification.

PATIENTS AND METHODS

Available pathology reports of 717 cases aged from 20 to 74 years in an Australian, population-based epidemiological study of NHL were reviewed by one anatomical pathologist to assign a World Health Organization (WHO) classification category. High or low confidence was assigned to the diagnosis of NHL, cell phenotype and WHO category and reasons given for low confidence.

RESULTS

The most informative biopsy reports were from open tissue biopsy (79% of cases), tissue core biopsy (8%), cytology (4%) and bone marrow (9%); 8% of cases had inadequate biopsies for diagnostic purposes. Immunohistochemistry or flow cytometry reports were available for 96% of cases, gene rearrangement studies for 6% and cytogenetics for 3%. The reviewer assigned high confidence to the diagnosis of NHL in 93% of cases and also the phenotype in 88%. While a WHO classification could be assigned in 91% of cases, confidence was high in only 57.5%; insufficient immunophenotyping was the commonest reason for low confidence.

CONCLUSIONS

Expert pathology review of a population-based sample of NHL can provide a WHO classification category for most cases. A high level of confidence in the classification, however, would require review of diagnostic material and additional phenotyping.

In a minority of gay men, sexual risk practice indicates strategic positioning for perceived risk reduction rather than unbridled sex

The aim of this analysis was to examine gay men's sexual risk practice to determine patterns of risk management. Ten cross-sectional surveys of gay men were conducted six-monthly from February 1996 to August 2000 at Sydney gay community social, sex-on-premises and sexual health sites (average n = 827). Every February during this period, five identical surveys were conducted at the annual Gay and Lesbian Mardi Gras Fair Day (average n = 1178). Among the minority of men who had unprotected anal intercourse which involved ejaculation inside with a serodiscordant regular partner, there was a clear pattern of sexual positioning. Few regular couples were both receptive and insertive. Most HIV-positive men were receptive and most HIV-negative men were insertive. Among the minority of men who had unprotected anal intercourse which involved ejaculation inside with casual partners, there was also a pattern of sexual positioning. Whereas many casual couples were both receptive and insertive (especially those involving HIV-positive respondents), among the remainder HIV-positive men tended to be receptive and HIV-negative men tended to be insertive. These patterns of HIV-positive/receptive and HIV-negative/insertive suggest strategic risk reduction positionings rather than mere sexual preferences among a minority of gay men. If so, they point not to complacency but to an ever more complex domain of HIV prevention.

Modelling the effect of combination antiretroviral treatments on HIV incidence

OBJECTIVE

To assess the competing effects on HIV incidence in homosexual men of the decreased infectiousness of men with HIV receiving effective combination antiretroviral treatments and homosexual men engaging in unprotected anal intercourse with increased numbers of partners (levels of unsafe sex).

METHODS

A mathematical model of HIV transmission in homosexual men was developed, based on the HIV epidemic in Australia in 1996, when effective antiretroviral treatments first became widely available. Uncertainties in parameters were modelled using 1000 simulations. The effect of treatments on decreasing infectiousness was randomly sampled with a median 10-fold decrease in infectiousness (range 100-fold to no decrease). Levels of unsafe sex were randomly sampled with a median 50% increase in unsafe sex (range 100% to no increase). The percentage change in HIV incidence after one year was obtained by comparison with a null model in which there was no decrease in infectiousness as a result of treatment and no change in unsafe sex.

RESULTS

Results of the models suggested that whereas increased levels of unsafe sex were linearly associated with increases in HIV incidence, decreases in infectiousness because of treatments were non-linearly associated with decreases in HIV incidence. An assessment of the competing effects suggested that decreases in infectiousness of two-, five-, and 10-fold would be counterbalanced by increases in unsafe sex of approximately 40, 60 and 70%, respectively.

CONCLUSION

These models suggest that apparently large decreases in infectiousness as a result of treatment could be counterbalanced in terms of new HIV infections by much more modest increases in unsafe sex.

Gay men's casual sex encounters: discussing HIV and using condoms

Some gay men disclose their HIV serostatus to enable them to decide to discard condoms in at least some casual encounters. In this paper we consider under what circumstances this occurs. We draw on data from the Sydney Men and Sexual Health cohort study, including both structured and semi-structured interviews. We find that casual sexual encounters among gay men are complex events, involving a broad range of types of partner and circumstance. A significant minority of men disclose their HIV serostatus; 36.3% of those who discussed their serostatus with casual partners engaged in unprotected anal intercourse (UAI) with those partners, while only 9.9% of those who did not discuss their serostatus engaged in UAI with those partners. We also find that disclosure of HIV serostatus, discussion and use of condoms during casual encounters are affected by the particular circumstances of those encounters, including the degree of familiarity between casual partners.

Solar keratoses: a risk factor for melanoma but negative association with melanocytic naevi

Solar keratoses have been associated with increased risk of squamous-cell and basal-cell carcinomas, but their association with melanoma is less clear. This study investigated solar keratoses as a risk factor for cutaneous melanoma in Australia, also associations between solar keratoses and other host factors associated with melanoma. A total-body naevus count was made of 258 melanoma cases and 281 controls recruited from New South Wales, Australia, and solar keratoses were counted on the left forearm. Solar elastosis was also assessed by clinical examination on the face and the side of the neck. Solar keratoses were a significant risk factor for melanoma in Australia. The presence of 10 or more solar keratoses on the left forearm (compared with none) was associated with an odds ratio of 4.7 (95% CI, 2.0-10.9). A highly significant association was found between number of solar keratoses and a past history of multiple basal-cell carcinomas in cases and controls respectively. Numbers of common and atypical naevi decreased significantly with age, while solar keratoses were more common in older individuals. Solar keratoses were found more commonly in men than women in cases and in controls (p < 0.0001). A negative association was found between numbers of common naevi and numbers of solar keratoses in cases and controls, and this remained significant after stratifying for age, gender and hair colour (p < 0.0001 and p < 0.0016 respectively). Solar keratoses were more common in males with melanoma on the head and neck as compared with melanoma on any other site. Solar keratoses and naevi were independently predictive of increased melanoma risk. The fact that these 2 phenotypes were found to be negatively associated suggests that susceptibility to melanoma may be expressed via 2 distinct cutaneous phenotypes which may be genetically determined.

The association between naevi and melanoma in populations with different levels of sun exposure: a joint case-control study of melanoma in the UK and Australia

Two case-control studies were set up to investigate the relationship between melanocytic naevi and risk of melanoma and to compare the naevus phenotype in two countries exposed to greatly different levels of sun exposure and different melanoma rates. In England 117 melanoma cases and 163 controls were recruited from the North-East Thames Region and 183 melanoma cases and 162 controls from New South Wales, Australia. Each subject underwent a whole-body naevus count performed by the same examiner in each country. Relative risks associated with melanocytic naevi in each country were calculated with comparison of naevus data in controls between Australia and England. Atypical naevi were strong risk factors for melanoma in both countries: the odds ratio (OR) for three or more atypical naevi was 4.6 (95% CI 2.0-10.7) in Australia compared with 51.7 (95% CI 6.5-408.4) in England. Common naevi were also significant risk factors in Australia and England with similar odds ratios in the two countries. Prevalence of atypical naevi was greater in Australian controls than in English controls: OR 9.7 (95% CI 1.2-81.7) for three or more atypical naevi in Australia compared with England. For young age groups, the median number of common naevi was greater in Australia than in the UK, whereas for older individuals this difference in naevi number between the two countries disappeared. The prevalence of naevi on non-sun-exposed sites in controls was not significantly different between the two countries. The atypical mole syndrome (AMS) phenotype was more prevalent in Australian controls (6%) than in English controls (2%). The results of this study support the role of sun exposure in the induction of atypical naevi in adults. There was a trend towards stronger risk factors associated with atypical naevi in England compared with Australia. The atypical mole syndrome, usually associated with a genetic susceptibility to melanoma, was more common in Australia than in England, suggesting genetic environmental interactions with the possibility of phenocopies induced by sunlight.

Sexual practices in a broad cross-sectional sample of Sydney gay men

The aim of this study was to provide current data on the sexual practices in a broad cross-sectional sample of gay and homosexually active men in Sydney. Anonymous, short questionnaires were completed by 1611 gay men recruited at the 1996 Gay and Lesbian Mardi Gras Fair Day or at one of six venues (including two sexual health centres) across the metropolitan area during the following week. The sample was diverse, but the men tended to be of Anglo-Australian background, well educated, professionally employed, attached to gay community and gay identified. They mainly had sex with other men rather than with men and women. Most (86.0 per cent) had been tested for human immunodeficiency virus. Excluding 241 men recruited in sexual health centres, 11.2 per cent were HIV-positive and 73.4 per cent were negative. Where it occurred in regular relationships, unprotected anal intercourse was usually between seroconcordant partners (78.5 per cent). Unprotected anal intercourse between discordant or nonconcordant regular partners was much less common, and in about half the cases involved withdrawal prior to ejaculation exclusively rather than ejaculation inside. Almost 12 per cent of the men had at least 'occasionally' engaged in unprotected anal intercourse with a casual partner in the previous six months, with approximately half of these men having adopted a withdrawal strategy on every occasion. We conclude that short surveys can provide valuable and timely data on sexual practices in a broad cross-sectional sample of gay and homosexually active men. Key messages for those involved in gay men's education are the high rates of unprotected anal intercourse between casual partners and the extensive practice of withdrawal.

Cancer in Rwanda

Data are presented on the frequency of malignant tumours registered at the population-based cancer registry in the southern prefecture of Butare, Rwanda, from May 1991 until 2 months before the outbreak of civil war in April 1994. Beginning in 1992, subjects were also interviewed about socio-demographic and life-style factors that have been associated with cancer risk in the West. The distribution of cancer in Rwanda is similar to that in other countries in sub-Saharan Africa. The most frequent cancers are those with possible infectious aetiologies: liver cancer (12%), cervical cancer (12%) and stomach cancer (9%). In addition, cancers known to be associated with HIV infection are relatively frequent (Kaposi's sarcoma [6%] and non-Hodgkin's lymphoma [3%]). Chronic infection, including infection with HIV, high parity and multiple sexual partners are important determinants of cancer incidence in this population. Tobacco consumption is low in Rwanda and there are few tobacco-related tumours, such as lung and laryngeal cancer. Other tumours believed to be associated with aspects of Western life-style, such as colorectal and breast cancer, are also relatively infrequent.