Pages

Tampilkan postingan dengan label transmission probability. Tampilkan semua postingan
Tampilkan postingan dengan label transmission probability. Tampilkan semua postingan

HIV Prevention in Women Requires a Full Toolbox

Via Medscape, by Emily Paulsen.

Women account for more than 50% of the worldwide AIDS epidemic, and a disproportionate number of those women are people of color. In the United States, black women make up a growing share of new AIDS cases; the rate for black women is nearly 20 times the rate for white women.

Although these statistics are dire, new research, presented here at the National Medical Association 2011 Annual Convention and Scientific Assembly, offers hope that the tide will turn on HIV transmission.

"This has been an amazing year for HIV research," Gina Brown, MD, told meeting attendees. Dr. Brown coordinates research on microbicides at the Office of AIDS Research, part of the National Institutes of Health in Bethesda, Maryland. She offered a "walk-through of some of the interesting things we've learned about what puts women at risk for HIV, and some of the interventions available."

The biggest news in HIV prevention, reported recently at the 6th International AIDS Society (IAS) Conference on HIV Pathogenesis, Treatment and Prevention, has been the use of antiretroviral therapy (ART) to reduce the risk for transmission, according to Dr. Brown. The HPTN 052 study showed a 96% reduction in transmission in serodiscordant couples in which the HIV-positive partner received early ART. In another study, once-daily tenofovir/emtricitabine (Truvada, Gilead Sciences) resulted in a 44% reduction in HIV transmission in men and transgender women who have sex with men. In that study, those who adhered to their medications at least 90% of the time achieved a 73% reduction in HIV transmission.

Dr. Brown pointed out that the couples in many of these studies were in steady relationships and volunteered to participate in the study. "Does this sound like the patients you see in your practice?" she asked the audience. She also said that costs and adverse effects might affect the practicality of this solution for many patients.

"When can we give up condoms?," she asked, answering that it would not likely be any time soon.

Dr. Brown said a full HIV prevention toolbox is still needed to reduce the risk for transmission. Education, partner reduction, treatment for sexually transmitted infections, condoms, circumcision, 1% tenofovir gel, and ART all offer varying amounts of protection. All interventions offer only harm reduction at this point, she said, not full protection.

Read the rest here.

[If an item is not written by an IRMA member, it should not be construed that IRMA has taken a position on the article's content, whether in support or in opposition.]

HIV Transmission Risk Through Anal Intercourse: systematic review, meta-analysis and

Via International Journal of Epidemiology by Rebecca F Baggaley, Richard G White, and Marie-Claude Boily

Background
The human immunodeficiency virus (HIV) infectiousness of anal intercourse (AI) has not been systematically reviewed, despite its role driving HIV epidemics among men who have sex with men (MSM) and its potential contribution to heterosexual spread. We assessed the per-act and per-partner HIV transmission risk from AI exposure for heterosexuals and MSM and its implications for HIV prevention.

Methods
Systematic review and meta-analysis of the literature on HIV-1 infectiousness through AI was conducted. PubMed was searched to September 2008. A binomial model explored the individual risk of HIV infection with and without highly active antiretroviral therapy (HAART).

Results
A total of 62 643 titles were searched; four publications reporting per-act and 12 reporting per-partner transmission estimates were included. Overall, random effects model summary estimates were 1.4% [95% confidence interval (CI) 0.2–2.5)] and 40.4% (95% CI 6.0–74.9) for per-act and per-partner unprotected receptive AI (URAI), respectively. There was no significant difference between per-act risks of URAI for heterosexuals and MSM. Per-partner unprotected insertive AI (UIAI) and combined URAI–UIAI risk were 21.7% (95% CI 0.2–43.3) and 39.9% (95% CI 22.5–57.4), respectively, with no available per-act estimates. Per-partner combined URAI–UIAI summary estimates, which adjusted for additional exposures other than AI with a ‘main’ partner [7.9% (95% CI 1.2–14.5)], were lower than crude (unadjusted) estimates [48.1% (95% CI 35.3–60.8)]. Our modelling demonstrated that it would require unreasonably low numbers of AI HIV exposures per partnership to reconcile the summary per-act and per-partner estimates, suggesting considerable variability in AI infectiousness between and within partnerships over time. AI may substantially increase HIV transmission risk even if the infected partner is receiving HAART; however, predictions are highly sensitive to infectiousness assumptions based on viral load.

Conclusions
Unprotected AI is a high-risk practice for HIV transmission, probably with substantial variation in infectiousness. The significant heterogeneity between infectiousness estimates means that pooled AI HIV transmission probabilities should be used with caution. Recent reported rises in AI among heterosexuals suggest a greater understanding of the role AI plays in heterosexual sex lives may be increasingly important for HIV prevention.

For the full study click here.