Infectiousness of HIV-infected men who have sex with men in the era of highly active antiretroviral therapy

Preexposure Prophylaxis for HIV Prevention: Grand Rounds Discussion From Beth Israel Deaconess Medical Center

The U.S. Public Health Service recently issued guidelines about the daily use of medication as preexposure prophylaxis (PrEP) to prevent HIV infection. The guidelines, based on randomized trials showing substantial reduction in HIV transmission among those receiving a daily combination of tenofovir and emtricitabine, suggest physicians offer PrEP to patients at high risk, including nonmonogamous men who have sex with men, serodiscordant couples (in both male-male and male-female relationships), heterosexual men and women in other risk groups (such as sex workers or those with recent sexually transmitted infection), and injection drug users. Here, 2 prominent HIV experts debate the use of PrEP in a 45-year-old man whose husband has HIV infection with an undetectable viral load on treatment. They discuss the patient's risk for HIV transmission from his husband and from other partners, the magnitude of the risk reduction he would gain with PrEP, and nonpharmacologic alternatives to reduce his likelihood of contracting HIV infection.

Cost-effectiveness of Methadone Maintenance Treatment in Prevention of HIV Among Drug Users in Shiraz, South of Iran

Background:

The increase in high-risk injections and unsafe sexual behaviors has led to increased HIV infection prevalence among Intravenous Drug Users (IDUs). The high costs of HIV/AIDS care and low financial resources necessitate an economic evaluation to make the best decision for the control of HIV/AIDS.

Objectives:

This study was conducted to determine the cost-effectiveness of Methadone Maintenance Treatment (MMT) centers in HIV infection prevention among drug users.

Materials and Methods:

In this interventional study, we included all the seven MMT centers and the drug users registered there (n = 694). We calculated all the costs imposed on the government, i.e. Provider of case. Mathematical models were used to estimate the number of HIV cases averted from high-risk behaviors. Sensitivity analyses were performed to show the effects of uncertainty in parameters on the number of HIV cases averted and also Incremental Cost-Effectiveness Ratio (ICER).

Results:

Based on the averted models, the selected MMT centers could prevent 128 HIV cases during 1 year. The total cost was $ 547423 and that of HIV/AIDS care in the no intervention scenario was estimated $ 14171816. ICER was $ 106382 per HIV case averted. The results of the sensitivity analysis indicated that MMT intervention was cost-effective even in the worst scenario and ICER varied from $ 39149 to $ 290004 per HIV case averted.

Conclusions:

With regard to the high prevalence of drug injection among drug users and considering the high effectiveness and cost-effectiveness of MMT centers in preventing HIV infection, establishment of MMT centers in regional and national levels seems reasonable.

Antiretroviral therapy for prevention of HIV transmission: implications for Europe

The aim of this review is to summarise the evidence on the population-level effect of antiretroviral therapy (ART) in preventing HIV infections, and to discuss potential implications in the European context of recommending starting ART when the CD4 count is above 350 cells/mm3. The ability of ART to reduce the risk of HIV transmission has been reported in observational studies and in a randomised controlled trial (HPTN 052), in which ART initiation reduced HIV transmission by 96% within serodiscordant couples. As yet, there is no direct evidence for such an effect among men having sex with men or people who inject drugs. HPTN 052 led international organisations to develop recommendations with a higher CD4 threshold for ART initiation. However, there remains a lack of strong evidence of clinical benefit for HIV-positive individuals starting ART with CD4 count above 350 cells/mm3. The main goal of ART provision should be to increase ART coverage for all those in need, based on the current guidelines, and the offer of ART to those who wish to reduce infectivity; increased HIV testing is therefore a key requirement. Other proven prevention means such as condom use and harm reduction for people who inject drugs remain critical.

HIV-negative gay men's perceived HIV risk hierarchy: imaginary or real?

HIV-related risk perceptions and risk practices among gay men have changed over time. We revisited perceived HIV risk and engagement in anal intercourse with casual partners among HIV-negative gay men who participated in one of the Sydney Gay Community Periodic Surveys (GCPS). Perceived HIV risk was assessed by a range of anal intercourse practices combined with pre-specified casual partners' HIV status and viral load levels. Perceived HIV risk forms a potential hierarchy, broadly reflecting differences in the probability of HIV transmission through various anal intercourse practices. To a lesser extent, it also varies by casual partners' HIV status and viral load. Men who had unprotected anal intercourse with casual partners (UAIC) perceived lower HIV risk than those who used condoms consistently in the 6 months prior to survey. Recognising the complex associations between risk perceptions and risk practices helps to better address challenges arising from the 'Treatment as Prevention' (TasP).

Further research needed to support a policy of antiretroviral therapy as an HIV prevention initiative

The results from the HPTN 052 trial have increased the focus on use of antiretroviral therapy (ART) for prevention of HIV transmission; however, condom use also effectively prevents HIV transmission. Studies in heterosexual serodiscordant couples with viral suppression have so far only reported follow-up data for 330 couple-years when condoms were not being used. Data are even more limited for anal sex in men who have sex with men. Additional data on the effectiveness of ART as prevention when practicing condom-less sex is urgently needed.

High HIV incidence among MSM prescribed postexposure prophylaxis, 2000-2009: indications for ongoing sexual risk behaviour

OBJECTIVE

To determine (trends in) HIV incidence among MSM\ who have recently had postexposure prophylaxis (PEP) prescribed in Amsterdam, compared with MSM participating in the Amsterdam Cohort Studies (ACS).

DESIGN AND METHODS

We used data from MSM who were prescribed PEP in Amsterdam between 2000 and 2009, who were HIV-negative at the time of PEP prescription and had follow-up HIV testing 3 and/or 6 months after PEP prescription (n = 395). For comparison, cohort data from MSM participating in the ACS in the same period were used (n = 782). Poisson log-linear regression analyses were performed to model trends in HIV incidence and identify differences in HIV incidence between both cohorts at different time points.

RESULTS

Between 2000 and 2009, among MSM who were prescribed PEP, an overall HIV incidence of 6.4 [95% confidence interval (CI) 3.4-11.2] per 100 person-years was found, compared with an HIV incidence of 1.6 (95% CI 1.3-2.1) per 100 person-years among MSM participating in the ACS (P < 0.01). In both cohorts, an increasing trend in HIV incidence over time was observed [incidence rate ratio (IRR(per calendar year)) 1.3 (95% CI 0.9-1.7) and 1.1 (95% CI 1.0-1.2) among MSM prescribed PEP and MSM of the ACS, respectively]. The difference in HIV incidence between both cohorts was most evident in more recent years [IRR(PEP versus ACS in 2009) 4.8 (95% CI 2.0-11.5)].

CONCLUSION

Particularly in more recent years, MSM recently prescribed PEP had a higher HIV incidence compared with MSM participating in the ACS, indicating ongoing sexual risk behaviour.

Modelling the impact of antiretroviral therapy on the epidemic of HIV

Thirty years after HIV first appeared it has killed close to 30 million people but transmission continues unchecked. In 2009, an estimated 1.8 million lives were lost and 2.6 million more people were infected with HIV [1]. To cut transmission, many social, behavioural and biomedical interventions have been developed, tested and tried but have had little impact on the epidemic in most countries. One substantial success has been the development of combination antiretroviral therapy (ART) that reduces viral load and restores immune function. This raises the possibility of using ART not only to treat people but also to prevent new HIV infections. Here we consider the impact of ART on the transmission of HIV and show how it could help to control the epidemic. Much needs to be known and understood concerning the impact of early treatment with ART on the prognosis for individual patients and on transmission. We review the current literature on factors associated with modelling treatment for prevention and illustrate the potential impact using existing models. We focus on generalized epidemics in sub- Saharan Africa, with an emphasis on South Africa, where transmission is mainly heterosexual and which account for an estimated 17% of all people living with HIV. We also make reference to epidemics among men who have sex with men and injection drug users where appropriate. We discuss ways in which using treatment as prevention can be taken forward knowing that this can only be the beginning of what must become an inclusive dialogue among all of those concerned to stop acquired immune deficiency syndrome (AIDS).

Antiretroviral therapy: a key component of a comprehensive HIV prevention strategy

Transmission of HIV is critically dependent on the level of HIV viral load within blood and genital secretions. Antiretroviral therapy results in sustained reductions in viral load to undetectable levels. Thus, antiretroviral therapy has long been postulated as a potential means to curb HIV transmission. Observational data have now confirmed that antiretroviral therapy is associated with a decrease in transmission among heterosexual serodiscordant couples, injection-drug users, and in population-based studies. Mathematical models suggest that further expansion of antiretroviral coverage within current guidelines can play a major role in controlling the spread of HIV. Concerns regarding the potential for transmission during acute HIV infection, behavioral disinhibition, and resistance to overcome the impact of treatment on prevention have not materialized to date. The Joint United Nations AIDS (UNAIDS) program has called for the inclusion of antiretroviral treatment as a key pillar in the global strategy to control the spread of HIV infection.