What Are Rectal Microbicides?

Currently in development, rectal microbicides are products that could be available in the form of lubricants, gels, douches or enemas that may be used to protect against HIV transmission and possibly other sexually transmitted infections (STIs) when used during anal intercourse (AI). Rectal microbicides could offer both primary protection in the absence of condoms and back-up protection if a condom breaks or slips off during AI.

For those unable or unwilling to use condoms, rectal microbicides could be a safe and effective alternative way of reducing risk, especially if they were discreet and/or enhanced sexual pleasure enough to motivate consistent use. Such alternatives are essential if we are to address the full spectrum of sexual practices and the basic human need for accessible, user-controlled HIV and STI prevention tools.

Why Do We Need Rectal Microbicides?

Over 33 million people are living with HIV globally. In many parts of the world, including North America, Latin America, Western Europe, Australia and New Zealand, unprotected AI is recognized as an important driver of the HIV pandemic. An act of unprotected AI is 5 to 80 times more likely to result in HIV transmission compared to an act of unprotected vaginal intercourse.

One of the dangerous silences of global HIV prevention efforts has been the neglect of anal intercourse between women and men. There is also silence around the HIV prevalence, and indeed the mere existence of, gay men and other men who have sex with men (MSM) in Asia, Africa and other parts of the developing world. This neglect costs lives.

Studies have shown that in many parts of Latin America, Africa and Asia, rates of HIV prevalence among gay men and other MSM are significantly higher than in the general population. Anal intercourse is a widely practiced behaviour among gay men and other MSM. The vast majority of Western gay men report having engaged in AI, approximately half of which is unprotected.

While rarely discussed in the scientific literature, AI is increasingly understood as a more common practice among heterosexuals. In the US and UK, between 10% and 35% of heterosexual women report practicing receptive AI, and lifetime reports of AI with opposite-sex partners are as high as 40% for US males. A conservative estimate is that seven times more heterosexual women than gay men in the US practice receptive AI. Unprotected AI between men and women has been linked to HIV infection in many parts of the world.

After more than 26 years into the HIV pandemic, the receptive partners during anal sex still have no prevention options they can control. Globally, almost all anal intercourse is unprotected.

What Is Happening in Research and Development?

Rectal microbicide research is more robust than it has ever been. In mid-2008, the world’s first rectal microbicide safety trial was completed at UCLA, and two more safety trials are in the planning stages. In addition, several research projects devoted to rectal microbicide-related topics are ongoing or have been recently completed, including projects that seek:

• to establish a pipeline of potential products to test as rectal microbicides

• to determine which formulations might work best rectally

• to describe current behaviors and practices related to anal sex

• to develop applicators and delivery systems that are appropriate for rectal use

• to establish the baseline parameters that could be assessed in rectal trials

• to facilitate the regulatory pathway

• to determine what kinds of products people would use

• to establish the rectal safety profile of sexual lubricants

What Are the Challenges?

There are significant biological, socio-cultural and political challenges surrounding the research and development of safe, effective and acceptable rectal microbicides. A great deal of denial and stigma surround anal intercourse, hampering efforts to collect accurate sexual behavior data. There is also a serious lack of adequate funding.

IRMA demands less silence and more science, and calls for at least a five-fold increase in funding for rectal microbicide research by 2010, from the current US $7 million/year to US $35 million/year. Governments and foundations from Europe, Canada, Australia and the United States should partner in this critical investment in desperately needed new prevention technologies.

The Bottom Line

Potential rectal microbicides must be safe and effective. They must also be acceptable, readily available and easy to use for all people who engage in AI. Unprotected AI is a significant driver of new HIV infections among gay men and other MSM, and likely plays a role in the epidemic between men and women. Men and women need and deserve prevention methods that offer them choices beyond condoms. Now is the time for rectal microbicides.

Learn More About Rectal Microbicides

International Rectal Microbicide Advocates (IRMA) is a network of nearly 700 advocates, scientists, policy makers and funders from six continents working together to advance a robust rectal microbicide research and development agenda. Visit www.rectalmicrobicides.org to learn more about IRMA, rectal microbicides, and the state of research. Find out how YOU can get involved today!