A Scientific American series examines how recent scientific advances will guide future efforts to thwart HIV/AIDS and also looks at the epidemic among men who have sex with men (MSM) and injecting drug users (IDUs).

When researchers announced during last month’s International AIDS Conference-AIDS 2010 that an antiretroviral-containing vaginal microbicide used by women before and after sex had reduced their risk of HIV infection by 39 percent, “it marked a significant thinning of the line between HIV treatment and prevention. The same agents that had been designed and developed to slow the virus’s proliferation within the human body now had the potential to be used to help bar it from successfully setting up shop in the first place,” Scientific American reports.

The article looks at how the results of the trial might inform “up-and-coming ARV-based prevention therapies such as” Pre-Exposure Prophylaxis (PrEP) as well as the great need for HIV prevention strategies to drive down the estimated 3 million new infections that take place annually in a challenging economic climate.

To translate the findings of the microbicide prevention trial “into something with real public-health impact, researchers need to confirm the findings and address a long list of new questions introduced by them: What is the best dosage and concentration? Could other ARV drugs do better? And what kind of delivery mechanism will best ensure that at-risk women actually use the preventive treatment?” the magazine writes. “Optimizing the gel to achieve protection for up to 70 or 80 percent of users would be ideal, notes [Paul] De Lay [deputy executive director of UNAIDS]. Additional studies will continue for at least the next couple of years. If a product could be rolled out in the developing world by 2013, he suggests it would be an ‘incredible accomplishment,'” the article continues.

De Lay also noted that flatlined funding for HIV/AIDS means there must be a focus on the “best value for our money.” De Lay added, “We can’t just treat our way out of the problem. And we can’t waste money on interventions that may not be valuable.”

The story also highlights additional HIV prevention strategies under investigation, including male circumcision and halting mother-to-child transmission. The article includes comments by Yasmin Halima, director for the Global Campaign for Microbicides, and Mitchell Warren, executive director of the AIDS Vaccine Advocacy Coalition (Peeples, 8/25).

In a related article, Scientific American explores MSM’s vulnerability to HIV infection and how they have largely “been ignored by most nations’ plans for HIV prevention and care. Cultural values – machismo, homophobia and religion have overridden the data and dominated policy decisions in many places.”

Though “MSM in developing countries are 19 times more likely to be infected with HIV than the general population, according to a 2007 literature review,” Scientific American writes that “85 countries still criminalize sexual activity between adults, and eight, including Nigeria and several Islamic countries, impose the death penalty for homosexual acts.”

The article asserts that a “trend toward scientific omission has reinforced local social stigma and violence directed against this minority,” and provides examples. The story includes comments by Chris Beyrer, director of the Johns Hopkins Center of Public Health and Human Rights, Steve Morin, director of the Center for AIDS Prevention Studies at the University of California, San Francisco, and Jeffrey O’Malley, director of the United Nations Development Programme (UNDP) HIV Group (Roehr, 8/25).

Meanwhile, another Scientific American article reports on HIV/AIDS among IDUs: “An estimated five million people have become infected with HIV through injection drug use (IDU) worldwide; nearly half of them are in China, Vietnam, Russia, Ukraine and Malaysia – almost all of which could be considered developing nations.”

The piece describes the risk of HIV infection among IDUs, several reasons for the global growth in injection drug use, and the Vienna Declaration, which aims to appeals for countries “to reorient government policies on injection drug use from focusing on prohibition, law enforcement and incarceration to focusing on treating addiction as a medical problem with medical solutions.”

The piece includes information on how harm reduction strategies, such as needle exchange programs can help drive down HIV transmission among IDU, before noting, “[e]xamples from Europe, Brazil, Hong Kong and several U.S. cities show that a package of harm-reduction interventions recommended by the World Health Organization (WHO) can keep the rate of new HIV infections low and stable among injection drug users for many years and not result in increased drug use.”

The article includes quotes from Julio Montaner, past-president of the International AIDS Society and director of the British Columbia Centre for Excellence in HIV/AIDS (Roehr, 8/25).