 |
|
|
| |
Antiretroviral-Treated People in HPTN 052 Start Having Safer Sex
|
| |
| |
XIX International AIDS Conference, July 22-27, 2012, Washington, DC
Mark Mascolini
Vaginal sex without condoms was rare among participants in the HPTN 052 trial and declined over 2 years of follow-up in both study arms [1]. The results indicate that antiretroviral therapy (ART) taken to prevent HIV transmission will not necessarily lead treated people to believe they can forsake condoms. At the same time, what happens in clinical practice may not mirror what happens in a trial like HPTN 052.
HPTN 052 found that starting ART at a CD4 count between 350 and 550--rather than waiting for a count of 250 or HIV-related symptoms--cut the risk of HIV transmission 96% [2]. But this treatment-as-prevention strategy raises concerns that antiretroviral-treated people will abandon protected vaginal and anal intercourse because they know ART lowers the risk of HIV transmission.
This landmark trial enrolled 1763 HIV-discordant couples in 9 countries in Africa, Asia, and the Americas and monitored them for a median of 2 years. The new analysis compared sexual behavior in HIV-positive partners before and after they started ART.
When people enrolled in HPTN 052, 4.0% in the early-treatment group and 5.7% in the delayed-treatment group reported condom-free vaginal intercourse with their primary partner. Three months into the trial, rates of unprotected vaginal intercourse dropped to 2.9% in the early group and to 3.0% in the delayed group (P = 0.9).
Through 2 years of follow-up, the rate of unprotected vaginal intercourse fell significantly among all study participants (beta = 0.015, P = 0.04), with no substantial difference between the early- and delayed-treatment arms.
Further analysis identified five factors that independently raised odds of reporting unprotected vaginal intercourse, at the following adjusted odds ratios (AOR) (and 95% confidence intervals):
-- Women versus men: AOR 1.6 (1.1 to 2.4)
-- From South America versus Asia: AOR 16.0 (8.2 to 31.3)
-- From Africa versus Asia: AOR 8.8 (5.0 to 15.6)
-- Substance use: AOR 2.2 (1.3 to 3.9)
-- Lower viral load at enrollment: AOR 0.7 (0.6 to 0.9)
Fewer than 0.3% of HPTN 052 participants reported unprotected anal intercourse when entering the trial, and that rate did not change over time.
After 2 years of follow-up, 91% of early-treated people had an undetectable viral load, compared with 22% in the delayed-treatment group. Among study participants taking antiretrovirals who reported unprotected vaginal or anal intercourse, 21% had a detectable viral load--so these people did pose a transmission risk.
The HPTN researchers concluded that randomization to early antiretroviral therapy "did not increase risk taking over several years." They believe "the decrease in sexual risk taking, coupled with effective virologic suppression, suggest that earlier initiation of [ART] could have sustained effects in decreasing HIV transmission." The HPTN 052 population may not reflect how sexual risk taking evolves in the clinic when people start ART, however, because trial participants had advantages some HIV-positive people do not have, such as quarterly visits, steady risk-reduction counseling, and access to free condoms.
References
1. Mayer K, Wang L, Hoffman I, et al. Sustained treatment as prevention: continued decreases in unprotected sex and increases in virological suppression after HAART initiation among participants in HPTN 052. XIX International AIDS Conference. July 22-27, 2012. Washington, DC. Abstract MOPDC0106.
2. Cohen MS, Chen YQ, McCauley M, et al. Prevention of HIV-1 infection with early antiretroviral therapy. N Engl J Med. 2011;365:493-505. http://www.nejm.org/doi/full/10.1056/NEJMoa1105243.
|
| |
|
|
|
|
|
