September 05, 2012
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Increased HIV prevention, treatment efforts needed in MSM

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Major advancements in the treatment and prevention of HIV infection have produced significant results against the disease and are paving the way to the end of the pandemic, but HIV remains less controlled in men who have sex with men across the world.

In the United States alone, MSM accounted for 61% of all new HIV infections during 2009 and almost half of those living with HIV in 2008, according to the most recent year national prevalence data online at www.aids.gov.

In a series of papers published in The Lancet and simultaneously presented during the recent International AIDS Conference in Washington, D.C., researchers urge for HIV prevention efforts to be scaled-up for MSM across low-middle- and high-income countries.

Figure 1. Chris Beyrer, MD, MPH, said it is critically important that people involved in HIV work understand that HIV in MSM cannot be ignored.

Source: Johns Hopkins Bloomberg School of Public Health

“It is unconscionable that so many years later, so many young men are still dying from HIV/AIDS — not because there isn’t treatment, but because of stigma and discrimination,”Chris Beyrer, MD, MPH, professor in the departments of epidemiology, international health, and health, behavior and society at the Johns Hopkins Bloomberg School of Public Health, said during a symposium on The Lancet series.

Global burden

There are many difficulties facing the HIV epidemic in MSM. The rates are alarming and cases appear to be increasing in not just poor, but also in rich countries, according to Stefan D. Baral, MD, of the Center for Public Health and Human Rights at Johns Hopkins Bloomberg School of Public Health.

In their Lancet paper, Baral and colleagues discussed findings from systematic reviews of the overall global epidemiology and disease burden of HIV in MSM between 2007 and 2011.

“Gay men and other MSM have been disproportionately affected by HIV since the beginning of the epidemic and in response, they have made major contributions benefiting all people affected by HIV,” Baral told Infectious Disease News.

“What’s really striking is whether you are looking at North, South and Central America, South and Southeast Asia or sub-Saharan Africa, there is a narrow range of HIV prevalence ranging from about 14% to 17% — there’s a lot of consistency across regions,” Baral said. “We saw the highest rates of HIV/AIDS in MSM of about 25% in countries of the Caribbean.”

Stefan D. Baral

The researchers examined individual level risks, including unprotected sex; network level risks that include the prevalence of HIV among marginalized groups, such as racial minorities; and structural risks, which include legal, policy and sociocultural conditions. They found that individual behaviors were necessary, but insufficient in explaining the massive HIV epidemics among MSM.

“When we started looking at the network level risk factors, we started to have a better appreciation of risk factors at this level,” Baral said. “But then we began looking at emerging and consistent data suggesting the role of structural level risks such as incarceration and stigma in limiting provisions and uptake of preventive services.”

Although prevention strategies to lower HIV transmission and risk exist, Baral said structural factors prevent MSM from seeking this information in many parts of the world.

Black MSM risk and outcomes

Data have confirmed that black MSM are at highest risk for HIV in the United States, but it has not been well established whether this is true for other countries. For this reason, Gregorio A. Millett, MPH, of the National Center for HIV/AIDS, Viral, Hepatitis, STD, and TB Prevention at the CDC, and colleagues set out to assess and compare the factors associated with disparities in HIV infection among black MSM in Canada, the United Kingdom and the United States.

The researchers found that similarities exist in the rates for HIV and STIs, as well the initiation of combination ART, in both the United Kingdom and the United States. Compared with an OR of 1.86 for HIV in black MSM in the United Kingdom, the OR for HIV in black MSM in the United States was 3.0. Black MSM in the United Kingdom (22%) and the United States (60%) were less likely to initiate combination ART when compared with all other MSM with HIV.

When comparing outcomes associated with HIV infection, US black MSM had the greatest disparities in structural barriers, the age and race of sex partners and HIV care and outcomes.

“Black gay men are 8.5 times more likely to have HIV when compared with other black populations, and black gay men across the world are 15 times more likely to be HIV-infected than the general population worldwide,” Millett said. “Elimination of disparities in HIV infection in black MSM cannot be accomplished without addressing structural barriers or differences in HIV clinical care access and outcomes.”

Biological risk and societal stigma

According to Baral and colleagues, a significant driver of HIV transmission in MSM appears to be anal intercourse. Data in their paper indicated a 1.4% transmission rate per act via receptive anal intercourse — 18-fold higher than the rate through vaginal sex.

With this risk at hand, the virus may be transmitted quickly through large networks of MSM. “Men have sexual role versatility, which increases the efficiency of transmission,” Baral said. “MSM often play both the receptive and insertive roles, which increases both risk and the speed of transmission in sexual networks. HIV prevention responses have to focus on the biology of transmission including lowering viral load among those infected with HIV as much as they should focus on behavioral approaches to increase condom use during sex and adherence to ART. ”

The researchers developed a stochastic agent-based network simulation model — a counterfactual experiment. For example, if sex between men carried the same transmission risks as sex between men and women, what would happen with HIV epidemics among MSM?

Results indicated that if you replace the transmission probability of anal intercourse with that of vaginal intercourse and also limit sexual role versatility by forcing 50% of men to always be the insertive partner and 50% to be the receptive partner, that 5-year cumulative incidence of HIV could decrease between 90% and 98%. Further, reducing unprotected anal intercourse in casual relationships will reduce HIV prevalence in MSM by between 29% and 51% in the same time frame. These results suggest that the biology of HIV transmission between men is extremely relevant in addressing the epidemics and exclusive focus on behaviors will not be sufficient in ending these epidemics.

In another paper in the series, Kenneth H. Mayer, MD, infectious diseases attending and director of HIV prevention research at Beth Israel Deaconess Medical Center, visiting professor of medicine at Harvard Medical School and medical research director at The Fenway Institute at Fenway Health, and colleagues focused on the unique health care needs of MSM.

“Our review of more than 1,000 papers found that some of the problems that sexual and gender minority persons develop later in life stem from early childhood trauma, including rejection by family, peers and key opinion leaders because of same sex attraction and gender nonconformity,” Mayer told Infectious Disease News. “Yet, the majority of MSM and other LGBT people lead healthy lives, suggesting a need to focus on the sources of resilience.”

Kenneth H. Mayer

According to background information in their paper, significant reductions in cases of HIV and STIs in MSM were observed during the early years of the HIV/AIDS epidemic — due to widespread introduction and use of condoms. Yet, societal influence and the “globally dominant legislative framework that does not recognize gay marriage might discourage the long-term maintenance of stable and safe homosexual relationships.”

“What is important is to take a life-course perspective in understanding the evolution of peoples’ sexuality and behavior,” Mayer said during his presentation. “A big part of this is that same-sex behavior and gender nonconformity remain stigmatized in large parts of the world, and youth are receiving societal messages that they are not accepted. This may result in loss of peers, family support and it may lead to depression and substance abuse.”

Stigmas such as these lead to nondisclosure of sexual preference to health care providers — resulting in missed opportunities for care.

“I want to make a plea that we think about culturally co0mpetent care and train the workforce and other clinical providers to care for this population,” he said. “One of the ironies is that health care providers may be uniquely positioned to assist MSM in their ‘coming out processes’ because of their social roles. We also have to think about the whole person — not just HIV, STIs or substance abuse, but their issues about families, relationships and mental health.”

Combination of prevention/intervention measures key

The increased biological risk of HIV transmission associated with anal intercourse, patterns of sexual relationships, the high prevalence of HIV among sex partners and the societal stigma affecting MSM requires a combination of intervention and prevention measures, according to Patrick Sullivan, PhD, DVM.

Sullivan, of the Center for AIDS Research at Emory University, and colleagues laid out the framework of a hypothetical structure for HIV prevention and intervention in MSM in the third paper of the series.

“Resources are scarce for HIV prevention services in MSM, and scale-up is problematic,” Sullivan and colleagues wrote in their paper. “Available interventions are insufficient, largely untested in most developing countries and not sufficiently tailored to MSM.”

As previously reported in Infectious Disease News, using ART as prevention and providing ART access to MSM worldwide may be feasible and would be a cost-effective management measure. However, substantial reductions in drug costs in low-income countries would be required for this to be achieved.

A hypothetical structure consisting of biomedical, behavioral and structural interventions and the incorporation of strategic prevention strategies could significantly decrease the risk for HIV in MSM, according to the researchers.

“We know that by packaging smart combinations of the prevention tools that we have today, we can have more impact,” Sullivan said. “Using new technologies, we can prevent one-quarter of new infections among MSM globally within the next decade. Different intervention approaches have different strengths and weaknesses in terms of efficacy, costs and scalability. No single approach is sufficient to turn the tides of the global HIV epidemics among MSM.”

Curbing the epidemic

According to Anthony Fauci, MD, director of the National Institute of Allergy and Infectious Diseases at the NIH, significant scientific challenges remain in HIV research, such as developing a vaccine and a cure. However, he said results from real-world settings strongly indicate that a global scale-up of existing and scientific evidence-based interventions could dramatically change the trajectory of the HIV/AIDS pandemic and ultimately lead to the end of AIDS.

“Ending the HIV/AIDS pandemic is an enormous and multifaceted challenge, but we now know it can be done,” Fauci said during the opening plenary session at the International AIDS Conference. “It will require continued basic and clinical research, and the development and testing of additional treatment and HIV prevention interventions and, importantly, implementing these interventions on a much wider scale.”

Curbing the HIV epidemic among MSM will require ongoing research, political will and structural reform, but community involvement is also needed. Since the beginning of the epidemic 30 years ago, MSM’s involvement in community leadership has aided in the protection of communities affected by HIV across the world. Improvements in the synergy of health and human rights and the expansion of research have occurred via community empowerment.

“Ultimately, stigmatizing contexts will limit the effectiveness of any HIV response,” Baral said. “To make legitimate progress towards an AIDS-free generation, we must end the paradoxical exclusion of gay men and other MSM from the HIV prevention, treatment and care services that they helped develop.”

“I hope this series is something of an invitation and a challenge for all of you,” Beyrer said. “It is critically important that the wider world of people involved in HIV work understand that this part of the epidemic can no longer be ignored or marginalized. We cannot get there without real structural change.We now have the evidence to say that this is an essential part of HIV everywhere we look and we need allies, partners and everyone to be reinvigorated.” — by Jennifer Henry

References:

Beyer C. Lancet. 2012;doi:10.1016/S0140-6736 (12)60821-6.

Beyer C. Lancet. 2012;doi:10.1016/S0140-6736 (12)61022-8.

Mayer K. Lancet. 2012;doi:10.1016/S0140-6736 (12)60835-6.

Millett GA. Lancet. 2012;doi:10.1016/S0140-6736 (12)60899-X.

Sullivan PS. Lancet. 2012;doi:10.1016/S0140-6736 (12)60955-6.

Trapence G. Lancet. 2012;doi:10.1016/S0140-6736(12)60834-4.

Disclosure: The researchers report no relevant financial disclosures.

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