A cross-sectional evaluation of correlates of HIV testing practices among men who have sex with men (MSM) in Mongolia

This study analyzed patterns and associations of HIV testing including sexual practices, HIV related knowledge, and human rights contexts among MSM in Mongolia. 313 participants were accrued using respondent-driven sampling and administered a structured questionnaire. Descriptive statistics are presented with crude and adjusted-point estimates with confidence intervals (95 % CI); and logistic regression models were used to identify factors associated with HIV testing in the last 12 months. RDS-adjustment demonstrated that 48.9 % (95 % CI = 36.7-58.3) of MSM had an HIV test in the past 12 months. Logistic regression revealed that experience of a human rights violation, enacted (OR = 0.50, 95 % CI = 0.26-0.97) or perceived (OR = 0.56, 95 % CI = 0.26-0.97), was inversely associated with a recent HIV test. Higher level of education (OR = 1.84, 95 % CI = 1.14-2.99), knowledge that anal sex is highest risk for HIV infection (OR = 4.54, 95 % CI = 2.41-8.56), and having 5 or more male sexual partners (OR = 1.82, 95 % CI = 1.00-3.30), were positively associated with a recent HIV test. MSM in Mongolia are at high risk for HIV infection and coverage of HIV testing is suboptimal. Understanding the variable sexual risk practices and barriers to HIV testing are vital to designing effective and relevant HIV-status dependent HIV intervention services.

The cost-effectiveness of expanded HIV screening in the United States

OBJECTIVE

The current Centers of Disease Control and Prevention (CDC) guidelines from 2006 recommend a one-time test for low-risk individuals and annual testing for those at high risk. These guidelines may not be aggressive enough, even for those at low risk of infection, due to the earlier initiation of HAART and a movement towards a test-and-treat environment. We evaluated the optimal testing frequencies for various risk groups in comparison to the CDC recommendations.

METHODS

We build a deterministic mathematical model optimizing the tradeoff between the societal cost of testing and the benefits over a patient's lifetime of earlier diagnosis.

RESULTS

Under a test-and-treat scenario with immediate initiation of HAART, the optimal testing frequency is every 2.4 years for low-risk (0.01% annual incidence) individuals; every 9 months for moderate risk (0.1% incidence) individuals; and every 3 months for high-risk (1.0% incidence) individuals. The incremental cost-effectiveness of the optimal policy is $ 36 ,342/quality-adjusted life-years (QALY) for low-risk individuals and $ 45 ,074/QALY for high-risk individuals compared with 20-year and annual testing, respectively.

CONCLUSION

The current CDC guidelines for HIV testing are too conservative, and more frequent testing is cost-effective for all risk groups.

Increased HIV testing will modestly reduce HIV incidence among gay men in NSW and would be acceptable if HIV testing becomes convenient

OBJECTIVE

Determine the acceptability and epidemiological impact of increases in HIV testing in gay men in New South Wales (NSW), Australia- particularly pertinent when considering treatment as prevention and the need to reduce undiagnosed infections.

METHODS

We conducted an online survey and focus groups to assess whether increases in HIV testing would be acceptable to gay men in NSW. In parallel, we assessed the potential impact of increases in testing coverage and/or frequency using an individual-based model of HIV transmission.

RESULTS

If sexual practices and the rate of initiating HIV treatment are unchanged then increasing HIV testing reduces infections. Increasing testing frequency has the largest impact, with a 13.8% reduction in HIV infections over 10 years if the ∼55-75% of men who test at least once per year increased their testing frequency to four times per year. If testing levels decrease from current levels then we expect an increase in HIV infections with a sharply rising trend over time. Increasing HIV testing would be acceptable if testing was more convenient. However, only ∼25% of men surveyed were 'very likely' to increase their level of HIV testing. Men delayed or avoided testing due to the slowness in obtaining results and if they believed they had not put themselves at risk.

CONCLUSIONS

An increase in HIV testing alone is unlikely to reduce HIV incidence substantially in NSW gay men- however, the relatively high testing levels need to continue to prevent an increase in HIV infections. In jurisdictions with lower levels of HIV testing, increases in testing coverage and frequency are likely to have a larger impact. Successful treatment as prevention interventions will require increases in testing rates; such increases would be acceptable to gay men in NSW but only if more convenient testing and rapid communication of results were available.

Reframing the context of preventive health care services and prevention of HIV and other sexually transmitted infections for young men: new opportunities to reduce racial/ethnic sexual health disparities

Young Black males, aged 13 to 29 years, have the highest annual rates of HIV infections in the United States. Young Black men who have sex with men (MSM) are the only subgroup with significant increases in HIV incident infections in recent years. Black men, particularly MSM, are also disproportionately affected by other sexually transmitted infections (STIs). Therefore, we must strengthen HIV and STI prevention opportunities during routine, preventive health care visits and at other, nontraditional venues accessed by young men of color, with inclusive, nonjudgmental approaches. The Affordable Care Act and National HIV/AIDS Strategy present new opportunities to reframe and strengthen sexual health promotion and HIV and STI prevention efforts with young men of color.

Feasibility and effectiveness of indicator condition-guided testing for HIV: results from HIDES I (HIV indicator diseases across Europe study)

Improved methods for targeting HIV testing among patients most likely to be infected are required; HIDES I aimed to define the methodology of a European wide study of HIV prevalence in individuals presenting with one of eight indicator conditions/diseases (ID); sexually transmitted infection, lymphoma, cervical or anal cancer/dysplasia, herpes zoster, hepatitis B/C, mononucleosis-like illness, unexplained leukocytopenia/thrombocytopenia and seborrheic dermatitis/exanthema, and to identify those with an HIV prevalence of >0.1%, a level determined to be cost effective. A staff questionnaire was performed. From October 2009– February 2011, individuals, not known to be HIV positive, presenting with one of the ID were offered an HIV test; additional information was collected on previous HIV testing behaviour and recent medical history. A total of 3588 individuals from 16 centres were included. Sixty-six tested positive for HIV, giving an HIV prevalence of 1.8% [95% CI: 1.42–2.34]; all eight ID exceeded 0.1% prevalence. Of those testing HIV positive, 83% were male, 58% identified as MSM and 9% were injecting drug users. Twenty percent reported previously having potentially HIV-related symptoms and 52% had previously tested HIV negative (median time since last test: 1.58 years); which together with the median CD4 count at diagnosis (400 cell/uL) adds weight to this strategy being effective in diagnosing HIV at an earlier stage. A positive test was more likely for non-white individuals, MSM, injecting drug users and those testing in non-Northern regions. HIDES I describes an effective strategy to detect undiagnosed HIV infection. All eight ID fulfilled the >0.1% criterion for cost effectiveness. All individuals presenting to any health care setting with one of these ID should be strongly recommended an HIV test. A strategy is being developed in collaboration with ECDC and WHO Europe to guide the implementation of this novel public health initiative across Europe.

Acute HIV-1 infection in the Southeastern United States: a cohort study

In 1998 a collaboration between Duke University and the University of North Carolina, Chapel Hill (UNC) was founded to enhance identification of persons with acute HIV-1 infection (AHI). The Duke-UNC AHI Research Consortium Cohort consists of patients ≥18 years old with a positive nucleic acid amplification test (NAAT) and either a negative enzyme immunoassay (EIA) test or a positive EIA with a negative/indeterminate Western blot. Patients were referred to the cohort from acute care settings and state-funded HIV testing sites that use NAAT testing on pooled HIV-1 antibody-negative samples. Between 1998 and 2010, 155 patients with AHI were enrolled: 81 (52%) African-Americans, 63 (41%) white, non-Hispanics, 137 (88%) males, 108 (70%) men who have sex with men (MSM), and 18 (12%) females. The median age was 27 years (IQR 22-38). Most (n=138/155) reported symptoms with a median duration of 17.5 days. The median nadir CD4 count was 408 cells/mm(3) (IQR 289-563); the median observed peak HIV-1 level was 726,859 copies/ml (IQR 167,585-3,565,728). The emergency department was the most frequent site of initial presentation (n=55/152; 3 missing data). AHI diagnosis was made at time of first contact in 62/137 (45%; 18 missing data) patients. This prospectively enrolled cohort is the largest group of patients with AHI reported from the Southeastern United States. The demographics reflect the epidemic of this geographic area with a high proportion of African-Americans, including young black MSM. Highlighting the challenges of diagnosing AHI, less than half of the patients were diagnosed at the first healthcare visit. Women made up a small proportion despite increasing numbers in our clinics.

[HIV test and prevention]

Successful prevention of an HIV epidemic is still a desirable goal. As young people are mainly affected by new infections and AIDS mortality has fallen virtually to zero, the long-term total costs of HIV management are increasing. This report describes how the targeted application of HIV testing can influence the HIV epidemic. The crucial point is the early diagnosis of primary HIV infection in standard situations whereby early diagnosis and counselling result in behavioral modifications preventing new transmission.

Missed opportunities for identifying primary HIV within genitourinary medical/HIV services

To assess the ability of three genitourinary medical centres to clinically identify primary HIV infection (PHI). Cases of recently acquired HIV infection, identified using the Health Protection Agency (HPA) avidity assay on all HIV diagnoses from January to August 2009, were investigated by case-note review. Sixty-four individuals were identified as PHI using the HPA avidity assay. Of 64 individuals, 31 (48%) were identified clinically. Imperial College identified 8/26 (31%), Guys and St Thomas' 15/27 (56%) and Brighton 8/11 (73%). Clinical suspicion of PHI was associated with reported unprotected anal intercourse (P = 0.017), seroconversion symptoms (P = 0.0004), a negative HIV test within six months (P = 0.024) and avidity assay result availability (P = 0.0169). Seventy percent of PHI cases missed had a documented risk factor. Thirty-five percent of those clinically identified with PHI were documented as informed of the associated enhanced infectivity. Suspicion of PHI was low despite documented risk factors and recent HIV-negative antibody tests. Counselling to prevent onward transmission was suboptimal.

Reconstituting the epidemic history of HIV strain CRF01_AE among men who have sex with men (MSM) in Liaoning, northeastern China: implications for the expanding epidemic among MSM in China

HIV CRF01_AE accounted for 84% of the recent infections among men who have sex with men (MSM) in Liaoning Province of northeastern China. CRF01_AE strains were grouped into two distinct clusters (designated clusters 1 and 2) that were also detected in other regions in China. Phylodynamics study revealed that these two CRF01_AE strains were independently introduced into the population of MSM in China in the early and mid-1990s. Our study elucidated unique features of dynamics and interrelationships of MSM epidemics in China.

[Consensus document of Gesida and Spanish Secretariat for the National Plan on AIDS (SPNS) regarding combined antiretroviral treatment in adults infected by the human immunodeficiency virus (January 2012)]

This consensus document has been prepared by a panel consisting of members of the AIDS Study Group (Gesida) and the Spanish Secretariat for the National Plan on AIDS (SPNS) after reviewing the efficacy and safety results of clinical trials, cohort and pharmacokinetic studies published in medical journals, or presented in medical scientific meetings. Gesida has prepared an objective and structured method to prioritise combined antiretroviral treatment (cART) in naïve patients. Recommendations strength (A, B, C) and the evidence which supports them (I, II, III) are based on a modification of the Infectious Diseases Society of America criteria. The current antiretroviral treatment (ART) of choice for chronic HIV infection is the combination of three drugs. ART is recommended in patients with symptomatic HIV infection, in pregnancy, in serodiscordant couples with high transmission risk, hepatitis B fulfilling treatment criteria, and HIV nephropathy. Guidelines on ART treatment in patients with concurrent diagnosis of HIV infection and an opportunistic type C infection are included. In asymptomatic patients ART is recommended on the basis of CD4 lymphocyte counts, plasma viral load and patient co-morbidities, as follows: 1) therapy should be started in patients with CD4 counts <350 cells/μL; 2) when CD4 counts are between 350 and 500 cells/μL, therapy will be recommended and only delayed if patient is reluctant to take it, the CD4 are stabilised, and the plasma viral load is low; 3) therapy could be deferred when CD4 counts are above 500 cells/μL, but should be considered in cases of cirrhosis, chronic hepatitis C, high cardiovascular risk, plasma viral load >10(5) copies/mL, proportion of CD4 cells <14%, and in people aged >55 years. ART should include 2 reverse transcriptase inhibitors nucleoside analogues and a third drug (non-analogue reverse transcriptase inhibitor, ritonavir boosted protease inhibitor or integrase inhibitor). The panel has consensually selected and given priority to using the Gesida score for some drug combinations, some of them co-formulated. The objective of ART is to achieve an undetectable viral load. Adherence to therapy plays an essential role in maintaining antiviral response. Therapeutic options are limited after ART failures, but an undetectable viral load may be possible nowadays. Adverse events are a fading problem of ART. Guidelines in acute HIV infection, in women, in pregnancy, and to prevent mother-to-child transmission and pre- and post-exposition prophylaxis are commented upon. Management of hepatitis B or C co-infection, other co-morbidities, and the characteristics of ART in HIV-2 infection are included.

Cost savings associated with testing of antibodies, antigens, and nucleic acids for diagnosis of acute HIV infection

Efforts to identify all persons infected with HIV in the United States are driven by the hope that early diagnosis will lower risk behaviors and decrease HIV transmission. Identification of HIV-infected people earlier in the course of their infection with HIV antigen/antibody (Ag/Ab) combination assays (4th-generation HIV assays) should help achieve this goal. We compared HIV RNA nucleic acid test (NAT) results to the results of a 4th-generation Ag/Ab assay (Architect HIV Ag/Ab Combo [HIV Combo] assay; Abbott Diagnostics) in 2,744 HIV antibody-negative samples. Fourteen people with acute HIV infection (HIV antibody negative/NAT positive) were identified; the HIV Combo assay detected nine of these individuals and was falsely negative in the remaining five. All five persons missed by the HIV Combo assay were in the stage of exponential increase in plasma virus associated with acute HIV infection (3, 7, 20, 35, 48). In contrast, most acutely infected persons detected by the HIV Combo assay demonstrated either a plateauing or decreasing plasma viral load. The HIV Combo assay also classified as positive five other samples which were negative by NAT. Taken together, the HIV Combo assay had a sensitivity of 73.7% and a specificity of 99.8%. Using published data, we estimated secondary transmission events had HIV infection in these five individuals remained undiagnosed. Screening of our population with NAT cost more than screening with the HIV Combo assay but achieved new diagnoses that we predict resulted in health care savings that far exceed screening costs. These findings support the use of more sensitive assays, like NAT, in HIV screening of populations with a high prevalence of acute HIV infection.

Less decrease in risk behaviour from pre-HIV to post-HIV seroconversion among MSM in the combination antiretroviral therapy era compared with the pre-combination antiretroviral therapy era

OBJECTIVE

To gain insight in the ongoing HIV transmission, we compared sexual risk behaviour pre-HIV and post-HIV seroconversion in 206 MSM participating in the Amsterdam Cohort Studies (1984-2008) before and after the introduction of combination antiretroviral therapy (cART).

DESIGN AND METHODS

MSM completed behavioural questionnaires and were tested for HIV antibodies every 6 months. Trends in anal intercourse and number of sex partners from 4 years before HIV seroconversion until 4 years after diagnosis were analysed with latent class random effects logistic regression models.

RESULTS

The risk of having unprotected anal intercourse (UAI) 1 year after HIV diagnosis decreased significantly when compared with 1 year before diagnosis in both the pre-cART era [difference, 30%; 95% confidence interval (CI), 22-36%] and cART era (difference, 19%; 95% CI, 9-30%). In contrast to a continuing decrease of UAI in the pre-cART era, the probability of UAI in the cART era increased again to preseroconversion levels (61%; 95% CI, 48-74%)) 4 years after diagnosis.

CONCLUSION

This study provides evidence that recently seroconverted MSM reduce their sexual risk behaviour following HIV diagnosis both in the pre-cART as well as the cART period. However, in the cART period this reduction in sexual risk behaviour is less and returns to pre-cART levels within 4 years. These findings not only confirm the need for early HIV testing but also make it clear that much more effort should go into identifying, counselling, and possibly treating recently seroconverted MSM who have been found to be one of the most important drivers of HIV transmission among MSM.

Actual and undiagnosed HIV prevalence in a community sample of men who have sex with men in Auckland, New Zealand

Background

The prevalence of HIV infection and how this varies between subgroups is a fundamental indicator of epidemic control. While there has been a rise in the number of HIV diagnoses among men who have sex with men (MSM) in New Zealand over the last decade, the actual prevalence of HIV and the proportion undiagnosed is not known. We measured these outcomes in a community sample of MSM in Auckland, New Zealand.

Methods

The study was embedded in an established behavioural surveillance programme. MSM attending a gay community fair day, gay bars and sex-on-site venues during 1 week in February 2011 who agreed to complete a questionnaire were invited to provide an anonymous oral fluid specimen for analysis of HIV antibodies. From the 1304 eligible respondents (acceptance rate 48.5%), 1049 provided a matched specimen (provision rate 80.4%).

Results

HIV prevalence was 6.5% (95% CI: 5.1-8.1). After adjusting for age, ethnicity and recruitment site, HIV positivity was significantly elevated among respondents who were aged 30-44 or 45 and over, were resident outside New Zealand, had 6-20 or more than 20 recent sexual partners, had engaged in unprotected anal intercourse with a casual partner, had had sex with a man met online, or had injected drugs in the 6 months prior to survey. One fifth (20.9%) of HIV infected men were undiagnosed; 1.3% of the total sample. Although HIV prevalence did not differ by ethnicity, HIV infected non-European respondents were more likely to be undiagnosed. Most of the small number of undiagnosed respondents had tested for HIV previously, and the majority believed themselves to be either "definitely" or "probably" uninfected. There was evidence of continuing risk practices among some of those with known HIV infection.

Conclusions

This is the first estimate of actual and undiagnosed HIV infection among a community sample of gay men in New Zealand. While relatively low compared to other countries with mature epidemics, HIV prevalence was elevated in subgroups of MSM based on behaviour, and diagnosis rates varied by ethnicity. Prevention should focus on raising condom use and earlier diagnosis among those most at risk, and encouraging safe behaviour after diagnosis.

The rate of HIV testing is increasing among men who have sex with men in China

OBJECTIVES

HIV infection is spreading relatively quickly among men who have sex with men (MSM) in China. Accurate knowledge of HIV status is of high importance for public health prevention.

METHODS

We conducted a systematic review of literature published in either English or Chinese to collate available HIV testing data among MSM in China. Linear regression and Spearman's rank correlation were used to study factors associated with HIV testing rates.

RESULTS

Fifty-five eligible articles were identified in this review. The proportion of MSM who had ever been tested for HIV has significantly increased, from 10.8% in 2002 to 51.2% in 2009. In comparison, reported rates of HIV testing in the past 12 months have also significantly increased, from 11.0% in 2003 to 43.7% in 2009.

CONCLUSIONS

Chinese MSM have relatively low HIV testing rates compared with MSM in other settings. It is important to continue to promote HIV testing among MSM in China.

Determinants of condom uptake among HIV voluntary counselling and testing clients: experiences from a hospital-based study in south India

Background

HIV voluntary counselling and testing was a key HIV prevention strategy brought to scale by India's National AIDS Control Organization. Condom uptake is an essential metric of intervention impact given the expansion of the epidemic into an increasingly diverse population. With only 20% of first-time counselling and testing clients at the largest HIV treatment hospital in south India reporting previous condom use, the question of intervention impact on condom use deserves investigation. In this study, we track intervention impact across various demographic groups and identify the added value of more thorough counselling.

Methods

Data were collected from 8,865 individuals who attended counselling multiple times at the Tamil Nadu Government Hospital of Thoracic Medicine over the years 2004-2009. Counsellors recorded client demographic characteristics, HIV risk behaviours reported, and counselling services provided after each counselling session. Matching and regression methods were used to determine the probability of condom uptake by serostatus, gender, and receipt of personalized risk reduction counselling while controlling for other characteristics.

Results

HIV counselling and testing was associated with condom uptake among 29.2% of HIV positive women (CI 24.5-34.4%), 31.7% of HIV positive men (CI 27.8-35.4%), 15.5% of HIV negative women (CI 11.2-20.8%), and only 3.6% of HIV negative men (CI 1.9-5.9%) who had previously never used condoms. Personalized risk reduction counselling increased impact in some groups; for example an additional 18% of HIV negative women (CI 11.3-24.4%) and 17% of HIV positive men (CI 10.9-23.4%) started using condoms. The number of sexual partners was not associated with the impact of counselling completeness.

Conclusions

Because the components of testing and counselling impact the condom use habits of men and women differently, understanding the dynamics of condom use negotiation between partners is essential to optimizing impact on Indian couples. Clients' predicted condom uptake ranged between 4% and 47% depending on factors like gender, serostatus, and services provided. Personalized risk reduction counselling is associated with increased chance of condom use, with larger gains in HIV negative women and HIV positive men. HIV negative men are least likely to start using condoms and least impacted by additional counselling.

Evaluating the extent of potential resistance to pre-exposure prophylaxis within the UK HIV-1-infectious population of men who have sex with men

OBJECTIVES

Recent studies have shown that pre-exposure prophylaxis (PrEP) can substantially reduce the chance of acquiring HIV infection. However, PrEP efficacy has been found to be compromised in macaque studies if the challenge virus is antiretroviral therapy (ART)-resistant. Our objective was to evaluate the likelihood that a UK man who has sex with men (MSM) would be exposed to PrEP-resistant HIV in a homosexual encounter with an HIV-infectious partner.

METHODS

Data from the UK Collaborative HIV Cohort (UK CHIC) study were linked to the UK HIV Drug Resistance Database for HIV-1-positive MSM patients seen between 2005 and 2008. Patients were categorized as undiagnosed; diagnosed but ART-naïve; ART-experienced and on treatment; and ART-experienced and on a treatment interruption. Considering current PrEP regimens, resistance to (a) tenofovir (TDF) alone, (b) TDF and emtricitabine (FTC), and (c) TDF or FTC was estimated. Patients without resistance tests had PrEP resistance imputed using bootstrapping and logistic regression models.

RESULTS

The population-level prevalence of PrEP resistance in HIV-infectious individuals in 2008 was estimated to be 1.6, 0.9 and 4.1% for PrEP resistance definitions a, b and c, respectively. Prevalence in ART-experienced patients was highest, with negligible circulating resistance amongst ART-naïve individuals. The levels of resistance declined over the period of study.

CONCLUSIONS

Our analysis indicates low levels of resistance to proposed PrEP drugs. The estimated PrEP resistance prevalence in UK HIV-infected MSM is towards the lower range of values used in simulation studies which have suggested that circulating PrEP drug resistance will have a negligible impact on PrEP efficacy at the population level.

HIV screening via fourth-generation immunoassay or nucleic acid amplification test in the United States: a cost-effectiveness analysis

Background

At least 10% of the 56,000 annual new HIV infections in the United States are caused by individuals with acute HIV infection (AHI). It unknown whether the health benefits and costs of routine nucleic acid amplification testing (NAAT) are justified, given the availability of newer fourth-generation immunoassay tests.

Methods

Using a dynamic HIV transmission model instantiated with U.S. epidemiologic, demographic, and behavioral data, I estimated the number of acute infections identified, HIV infections prevented, quality-adjusted life years (QALYs) gained, and the cost-effectiveness of alternative screening strategies. I varied the target population (everyone aged 15-64, injection drug users [IDUs] and men who have sex with men [MSM], or MSM only), screening frequency (annually, or every six months), and test(s) utilized (fourth-generation immunoassay only, or immunoassay followed by pooled NAAT).

Results

Annual immunoassay testing of MSM reduces incidence by 9.5% and costs <$10,000 per QALY gained. Adding pooled NAAT identifies 410 AHI per year, prevents 9.6% of new cases, costs $92,000 per QALY gained, and remains <$100,000 per QALY gained in settings where undiagnosed HIV prevalence exceeds 4%. Screening IDUs and MSM annually with fourth-generation immunoassay reduces incidence by 13% with cost-effectiveness <$10,000 per QALY gained. Increasing the screening frequency to every six months reduces incidence by 11% (MSM only) or 16% (MSM and IDUs) and costs <$20,000 per QALY gained.

Conclusions

Pooled NAAT testing every 12 months of MSM and IDUs in the United States prevents a modest number of infections, but may be cost-effective given sufficiently high HIV prevalence levels. However, testing via fourth-generation immunoassay every six months prevents a greater number of infections, is more economically efficient, and may obviate the benefits of acute HIV screening via NAAT.

Sexual mixing patterns among social networks of HIV-positive and HIV-negative Beijing men who have sex with men: a multilevel comparison using roundtable network mapping

Men who have sex with men (MSM) are of immediate concern in China's HIV epidemic. In 2008, approximately 2.5-6.5% of China's eight million MSM were HIV positive, while MSM represented 11% of all new HIV cases. Two factors that will in-part determine HIV-transmission dynamics among MSM, are sexual mixing patterns and the social networks which shape them. Sexual mixing patterns and social networks of Chinese MSM, however, remain poorly understood with little refined data available. One reason is that stigma discourages disclosure of names and identifiers to researchers. Using an alternative network-mapping approach, matched case-control design, and snowball sampling, this pilot study sought to compare characteristics of social networks of HIV-positive and HIV-negative Beijing MSM at the individual, dyad, and network levels. First, HIV-negative MSM controls were matched to HIV-positive MSM cases based on age, education, residency, and ethnicity. Then, each case or control and their MSM social network convened at a specific time and location with study investigators. Venues included health clinics, karaoke clubs, brothels, and community centers. Then, using arbitrarily assigned numbers in lieu of actual names, all participants simultaneously completed self-administered surveys regarding their sexual relationships with other participants of the same social network. These new findings indicate that cross-generational sex (anal or oral sex between men with ≥10 years age difference) was more prevalent among social networks of HIV-positive MSM, and was due to older age structure of the social network, rather than behavioral differences in sex-partner selection. Members of social networks of HIV-positive MSM were also less likely to have ever disclosed their MSM identity to non-MSM. Future studies should partner with MSM advocacy groups to explore behavioral and structural interventions as possible means of reducing the cross-generational sex and sexual identity-development issues elevating HIV risk for young Chinese MSM.

'Test-and-treat': the end of the HIV epidemic?

PURPOSE OF REVIEW

The aim is to review recent literature on 'test-and-treat', a prevention strategy that promotes high levels of HIV testing and initiating antiretroviral therapy upon diagnosis, regardless of CD4 cell count. Antiretroviral therapy (ART) has been shown to dramatically reduce viral load which is strongly associated with the risk of transmission, therefore there is the potential to reduce HIV transmissions with ART.

RECENT FINDINGS

Recent papers from observational studies on heterosexual sero-discordant couples found an overall rate of transmission of HIV-1 from ART-treated patients of 0.46 per 100 person-years, confirming the possibility of using ART as a prevention strategy. Several models have been used to predict the effect of this strategy and the potential risks of it. Randomized controlled trials are currently ongoing investigating the effect of ART on reducing infectiousness and the feasibility of this policy.

SUMMARY

More precise estimations of the transmission risk under virally suppressive ART (especially in MSM) and of change in sex risk behaviour at diagnosis and at start of ART are needed. Further, the benefit to individual health of very early ART initiation and the feasibility of this policy need to be evaluated. Achieving very high levels of testing should be a high priority due to the benefits of initiating ART in all those who are in need (CD4 cell count < 350 cells/μl) and potential benefits on incidence due to reductions in risk behaviour in those diagnosed. Use of ART immediately at diagnosis in those with high CD4 cell counts should await results from further studies.

To use or not to use: an update on licit and illicit ketamine use

Ketamine, a derivative of phencyclidine that was developed in the 1960s, is an anesthetic and analgesic with hallucinogenic effects. In this paper, the pharmacological and toxicological effects of ketamine are briefly reviewed. Ketamine possesses a wide safety margin but such a therapeutic benefit is somewhat offset by its emergence phenomenon (mind-body dissociation and delirium) and hallucinogenic effects. The increasing abuse of ketamine, initially predominantly in recreational scenes to experience a “k-hole” and other hallucinatory effects but more recently also as a drug abused during the workday or at home, has further pushed governments to confine its usage in many countries. Recently, urinary tract dysfunction has been associated with long-term ketamine use. In some long-term ketamine users, such damage can be irreversible and could result in renal failure and dialysis. Although ketamine has not yet been scheduled in the United Nations Conventions, previous studies using different assessment parameters to score the overall harms of drugs indicated that ketamine may cause more harm than some of the United Nations scheduled drugs. Some countries in Southeast and East Asia have reported an escalating situation of ketamine abuse. Dependence, lower urinary tract dysfunction, and sexual impulse or violence were the most notable among the ketamine-associated symptoms in these countries. These results implied that the danger of ketamine may have been underestimated previously. Therefore, the severity levels of the ketamine-associated problems should be scrutinized more carefully and objectively. To prevent ketamine from being improperly used and evolving into an epidemic, a thorough survey on the prevalence and characteristics of illicit ketamine use is imperative so that suitable policy and measures can be taken. On the other hand, recent findings that ketamine could be useful for treating major depressive disorder has given this old drug a new impetus. If ketamine is indeed a remedy for treating depression, more research on the risks and benefits of its clinical use will be indispensable.

Increased HIV testing and reduced undiagnosed infection among gay men in Scotland, 2005-8: support for the opt-out testing policy?

Objective

To examine changes in HIV testing and undiagnosed infection among men who have sex with men in Scotland between 2005 and 2008.

Methods

Self-completed questionnaires and Orasure oral fluid collection kits were distributed to men visiting the commercial gay scene in Glasgow and Edinburgh.

Results

Questionnaires and oral fluid specimens were provided by 1350 men (51.6% response rate) in 2005 and 1277 (59.7% response rate) in 2008. 2572 men were eligible for inclusion in the analyses. Recent HIV testing increased from 33.2% in 2005 to 48.3% in 2008 (p<0.001). HIV prevalence was comparable in 2005 and 2008 (4.4% and 4.6%, respectively). Among HIV-positive men, there was a reduction in undiagnosed infection between 2005 and 2008 from 41.7% to 26.3% (p=0.08). Undiagnosed HIV did not differ between men who were and were not tested in the past year. In 2008, only four (26.7%) HIV-positive men tested in the past 6 months were undiagnosed, compared with 11 (42.3%) HIV-positive men who had not tested (p=0.03).

Conclusion

There was a substantial increase in recent HIV testing between 2005 and 2008. Although there was a concurrent (non-significant) reduction in undiagnosed HIV, there was no difference in undiagnosed infection between men who had and had not tested recently. However, lower proportions of undiagnosed infection among the most recent HIV-positive testers suggest frequent testing could play a role in reducing undiagnosed HIV and should remain central to HIV prevention efforts.

Antiretroviral treatment of primary HIV infection to reduce onward transmission

PURPOSE OF REVIEW

This review will discuss the role of antiretroviral therapy to treat primary HIV infection (PHI) as a strategy to prevent onward viral transmission.

RECENT FINDINGS

Novel technology has greatly enhanced the appreciation of the characteristics of recently transmitted HIV-1 variants. Recent primate data demonstrate marked enhanced infectiousness of viral variants isolated from acutely infected macaques compared with viruses isolated from animals in the chronic phase of disease. These data are supported by phylogenetic analyses of recently transmitted cases in humans, implying that individuals with PHI may contribute disproportionately to onward transmission at a population level.

SUMMARY

In the absence of randomized clinical trial data supporting individual benefit of antiretroviral therapy, targeting and treating individuals with PHI as a public health intervention strategy represent a paradigm shift from current treatment strategies based around proven individual benefit alone. However, there is increasing evidence that PHI contributes disproportionately to viral transmission at a population level and failure to incorporate the potential role PHI plays, particularly in focused epidemics, maybe a naïve omission of many of the current mathematical models evaluating the impact of universal test and treat on population-level HIV incidence.

An overview of the relative risks of different sexual behaviours on HIV transmission

PURPOSE OF REVIEW

Sexual intercourse represents the majority of HIV transmission and is preventable. Overall, the risk of HIV transmission following a single sexual exposure is low especially in comparison with other sexually transmitted infections (STIs), with estimates of the average probability of male-to-female HIV transmission only 0.0005-0.0026 per coital act. The risk of acquiring HIV from a single contact varies enormously and is dependant upon the infectiousness of the HIV-positive individual and the susceptibility to HIV of their sexual partner.

RECENT FINDINGS

Of concern, unprotected sex among men who have sex with men (MSM) has increased in recent years and HIV incidence in both MSM and heterosexuals remains a considerable public health concern. Sexual practices and health optimism about HIV have changed, which have significantly impacted HIV risk behaviour.

SUMMARY

In this review article we summarize the current evidence regarding the observed relative risks of HIV transmission for each different types of sex act, relationship type and the strategies that have been tested to interrupt transmission.

Determinants of HIV-1 transmission in men who have sex with men: a combined clinical, epidemiological and phylogenetic approach

OBJECTIVES

To identify biological factors associated with HIV transmission in men who have sex with men (MSM).

DESIGN

A longitudinal phylogenetic analysis of HIV-1 from an MSM cohort, incorporating clinical and epidemiological data.

METHODS

Potential individuals were HIV-infected MSM attending a sexual health clinic between 2000 and 2006. Individuals were classified such that they could move from recent to chronic infection categories. HIV-1pol gene sequences were obtained from plasma virus or proviral DNA and clusters estimated by maximum likelihood and conservative genetic distance differences. The single most likely transmitter generating each recent infection was ascertained and risk factors around time of likely transmission explored using Poisson regression modelling.

RESULTS

Out of 1144 HIV-infected MSM, pol sequence data were obtained for 859 (75%); 159 out of 859 (19%) were recently HIV infected at diagnosis. A single most likely transmitter was identified for 41 out of 159 (26%), of which 11 were recently infected (27%) and 30 chronically infected. Factors associated with transmission in multivariable analysis were: younger age {rate ratio per 5 years older 0.68 [95% confidence interval (CI) 0.54-0.86], P=0.0009}, higher viral load [rate ratio per log higher 1.61 (95% CI 1.15-2.25), P=0.005], recent infection [rate ratio 3.88 (95% CI 1.76-8.55), P=0.0008] and recent sexually transmitted disease [rate ratio 5.32 (95% CI 2.51-11.29), P=0.0001]. HAART was highly protective in a univariable model, RR 0.14 (95% CI 0.07-0.27, P=0.0001).

CONCLUSION

Onward transmission of HIV among MSM is significantly associated with recent infection, sexually transmitted diseases and higher viral load, and reduced by effective HAART. The majority of new infections appear to occur from individuals whose infection was undiagnosed at the time of transmission.

Sexual transmission of HIV-1

HIV-1 transmission occurs in a limited number of ways all of which are preventable. Overall, the risk of HIV-1 transmission following a single sexual exposure is low especially in comparison with other sexually transmitted infections (STIs); with estimates of the average probability of male to female HIV-1 transmission only 0.0005-0.0026 per coital act. The risk of acquiring HIV-1 from a single contact varies enormously and is dependant upon the infectiousness of the HIV-1 positive individual and the susceptibility to HIV-1 of their sexual partner. An understanding of the determinants of HIV-1 transmission is important not only to assess the infection risk to an individual when exposed to the virus (e.g. to determine the provision of post exposure prophylaxis), but also to make accurate predictions on the potential spread of HIV-1 infection in a population and to direct appropriate targeted prevention strategies. In this review article we summarise the current literature on the major worldwide source of HIV-1 acquisition, sexual transmission. This article forms part of a special issue of Antiviral Research marking the 25th anniversary of antiretroviral drug discovery and development, Vol 85, issue 1, 2010.