New HIV infections among gay and bisexual men in the United States have fallen over the past few years, in part due to earlier and more widespread use of effective antiretroviral therapy, according to the Centers for Disease Control and Prevention.
"When ART results in viral suppression, defined as less than 200 copies/ml or undetectable levels, it prevents sexual HIV transmission," Drs. Eugene McCray and Jonathan Mermin of the CDC said in a September 27 statement recognizing National Gay Men's HIV/AIDS Awareness Day. "This means that people who take ART daily as prescribed and achieve and maintain an undetectable viral load have effectively no risk of sexually transmitting the virus to an HIV-negative partner."
This is thought to be the first time the CDC has formally acknowledged that HIV-positive people on antiretroviral treatment with an undetectable viral load do not transmit the virus, a statement now supported by extensive research.
The PARTNER study, which looked at nearly 900 mixed-status heterosexual and gay male couples, found no evidence of transmission between discordant partners in more than 58,000 sex acts when the positive partner was on treatment with undetectable HIV. The Opposites Attract study did not see a single case of transmission among 300 gay male couples meeting the same criteria who engaged in nearly 17,000 acts of anal sex without condoms.
"There is no such thing as zero risk, and I think it would be foolish to say that, but we live in a society where we accept some risks," National Institute of Allergy and Infectious Diseases director Dr. Anthony Fauci told reporters at this summer's International AIDS Society Conference on HIV Science in Paris. "What the data are telling us is that the risk is exceedingly low, almost to the point of being unmeasurable."
Advocates have expressed concern that not enough people are aware of this message, and a group of them interrupted a plenary session at the conference to unfurl a banner proclaiming "Undetectable = Untransmittable."
"The CDC's updated risk assessment is a historic shift in what it means to be a person living with HIV, and provides a powerful argument for universal access to treatment and care for both personal and public health reasons," Bruce Richman of the Prevention Access Campaign, who took part in that demonstration, told Aidsmap.
How many are undetectable?
The key factor in the "Undetectable = Untransmittable" equation is that people with HIV must actually maintain full viral suppression. This means regular testing to detect new infections early, prompt treatment starting as soon as possible after HIV diagnosis, and ongoing good adherence to antiretroviral therapy.
According to the CDC, men who have sex with men remain heavily affected by the HIV epidemic. More than 26,000 gay and bi men were newly diagnosed with HIV in 2015, representing two-thirds of all new diagnoses in the United States.
The latest data show that new infections among gay and bi men have finally started to drop, however. New HIV diagnoses declined among white gay men and remained stable among African-American gay men between 2010 and 2014, though Latino gay men saw a small increase.
Locally, the San Francisco Department of Public Health recently released its latest HIV epidemiology report, showing that new HIV diagnoses continue to decline across racial and ethnic groups. As previously reported, this year's 16 percent decline, bringing new diagnoses down from 265 in 2015 to 223 in 2016, follows a 15 percent decline the previous year.
Experts attributed the decline to a combination of factors including increased testing and the advent of PrEP for HIV prevention, along with early antiretroviral treatment.
But many gay and bi men are still not getting the care they need to maintain an undetectable viral load. Among men with diagnosed HIV in 2014, about 74 percent had received any HIV care and just 61 percent had achieved viral suppression, according to the September 22 edition of the CDC's Morbidity and Mortality Weekly Report.
San Francisco continues to do a better job than the United States as a whole in moving people through the HIV continuum of care. The DPH report estimated that 76 percent of all gay and bi men living with HIV in the city in 2015 had undetectable viral load, rising to 82 percent among newly diagnosed gay men. But here, too, disparities remain, with African-Americans having the lowest viral suppression rate.
"More work is needed to close this gap and to address the barriers that make it more difficult for some gay and bisexual men, including African-American and Hispanic/Latino men, to get HIV care and treatment," McCray and Mermin wrote. "[W]hile there is still much work to do, today we have powerful prevention and treatment tools that can dramatically reduce HIV infections among gay and bisexual men and move us closer to a future free of HIV."
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