Navigation Links
Viral load a major factor affecting risk of sexually transmitting HIV

The level of HIV-1 in the blood of an HIV-infected partner is the single most important factor influencing risk of sexual transmission to an uninfected partner, according to a multinational study of heterosexual couples in sub-Saharan Africa. The study, published in the Journal of Infectious Diseases, calculated the risk of HIV-1 transmission per act of sexual intercourse and found the average rate of infection to be about 1 per 900 coital acts. The findings also confirmed that condoms are highly protective and reduce HIV infectivity by 78 percent.

James P. Hughes, PhD, and colleagues at the University of Washington and the Fred Hutchinson Cancer Research Center, in Seattle; the University of Witwatersrand in South Africa; the University of Nairobi and Kenyatta National Hospital, in Kenya; and the Rwanda-Zambia HIV Research Group conducted a study that included 3,297 HIV-discordant couples (where one person is HIV-infected, and the other is not) in eastern and southern Africa who were enrolled in a randomized trial of acyclovir suppressive therapy. The couples had frequent follow-up to measure plasma HIV-1 RNA in the infected partner and genetic testing to link the transmitted virus to the index HIV-infected partner, to prevent inclusion of infections acquired from other possible partners. HIV acquisition was not affected by the acyclovir therapy.

The study confirmed that condoms are highly protective, reducing the risk of HIV transmission by 78 percent when subjects reported using a condom. Most important, the authors noted, was the level of HIV-1 RNA in the blood of the infected partner. The higher the viral load in the index infected partner, the higher the risk of transmission, emphasizing the importance of lowering viral load to help prevent the spread of HIV-1 through sex. Older age was associated with reduced transmission per sex act, and male circumcision reduced female-to-male transmission by approximately 47 percent. Genital herpes infections and the presence of genital ulcers were associated with increased rates of transmission.

"Our results underscore the importance of antiretroviral therapy, and, possibly, treatment of co-infections, to reduce plasma HIV-1 viral load in HIV-1 infected partners, and condom promotion, male circumcision, and treatment of symptomatic sexually-transmitted infections for HIV-1 uninfected partners as potential interventions to reduce HIV-1 transmission," the authors wrote.

The findings also showed that the risk of an HIV-infected man transmitting an infection to a woman not infected with HIV was about twice the risk of an HIV-infected woman transmitting to an HIV-uninfected man. However, this difference can be attributed to the difference in viral loads between men and women, the authors noted. On average, HIV-infected men have higher HIV-1 loads. Difference in age and having genital herpes in the HIV-uninfected partners also help account for the disparitythe HIV-uninfected female partners were, on average, younger and had higher rates of genital herpes than their male counterparts.

Previous studies examining HIV-1 per-act infectivity have been significantly smaller and not as comprehensive in terms of measuring plasma HIV-1 RNA and the use of genetic linkage of transmissions. In an editorial commentary, Ronald H. Gray, MD, and Maria J. Wawer, MD, both of Johns Hopkins University in Baltimore, noted that Dr. Hughes and his colleagues have possibly recorded the most precise estimates of HIV-1 transmission per sexual act during latent HIV disease, providing a valuable addition to knowledge in this area, where much remains to be learned.

Additional research using the genetic data collected from this study, in addition to new data from another recently completed clinical trial, is planned to help explain the variation in transmission risk among couples, the authors noted.

Fast Facts:

1. In HIV-discordant coupleswhere one partner is infected with HIV, and the other is notviral load of the infected partner was a major factor affecting the HIV transmission rate.

2. Condom use among HIV-discordant couples was 78 percent effective in preventing transmission to the uninfected partner.

3. Factors such as age, male circumcision status, and sexually transmitted infections also affected transmission probability.

Contact: John Heys
Infectious Diseases Society of America

Related medicine news :

1. Pep talk can revive immune cells exhausted by chronic viral infection
2. Ohio State researchers design a viral vector to treat a genetic form of blindness
3. Antiviral drugs may slow Alzheimers progression
4. UC Irvine study points to new approach to influenzas antiviral resistance
5. Arrival of direct antiviral agent therapy for hepatitis C sparks debate of who to treat first
6. Treating HIV-infected people with antiretrovirals significantly reduces transmission to partners
7. UNC-led study shows early treatment with antiretroviral therapy prevents HIV transmission
8. Lack of health insurance limits hepatitis C patients access to latest antiviral therapy
9. Viral protein mimic keeps immune system quiet
10. Study shows durable viral suppression of boosted REYATAZ in treatment-experienced HIV patients
11. Hepatitis C study shows superior viral cure rate
Post Your Comments:
(Date:6/26/2016)... Michigan (PRWEB) , ... June 26, 2016 , ... ... to fertility once they have been diagnosed with endometriosis. These women need a ... they also require a comprehensive approach that can help for preservation of fertility ...
(Date:6/25/2016)... ... June 25, 2016 , ... Austin residents seeking Mohs surgery services, ... Mohs Surgery and to Dr. Russell Peckham for medical and surgical dermatology. , Dr. ... skin cancer. The selective fellowship in Mohs Micrographic Surgery completed by Dr. Dorsey was ...
(Date:6/25/2016)... ... June 25, 2016 , ... "With 30 hand-drawn hand gesture animations, FCPX users ... - CEO of Pixel Film Studios. , ProHand Cartoon’s package transforms over 1,300 ... Pro X . Simply select a ProHand generator and drag it above media or ...
(Date:6/25/2016)... Long Beach, CA (PRWEB) , ... June 25, 2016 , ... ... from UCLA with Magna Cum Laude and his M.D from the David Geffen School ... San Diego and returned to Los Angeles to complete his fellowship in hematology/oncology at ...
(Date:6/25/2016)... ... ... On Friday, June 10, Van Mitchell, Secretary of the Maryland Department of ... recognition of their exemplary accomplishments in worksite health promotion. , The Wellness at Work ... Symposium at the BWI Marriott in Linthicum Heights. iHire was one of 42 businesses ...
Breaking Medicine News(10 mins):
(Date:6/23/2016)... DUBLIN , June 23, 2016 ... the "Pharmaceutical Excipients Market by Type (Organic Chemical ... Preservative), Formulation (Oral, Topical, Coating, Parenteral) - Global Forecast ... The global pharmaceutical excipients ... 2021 at a CAGR of 6.1% in the forecast ...
(Date:6/23/2016)... June 23, 2016 Capricor ... ), a biotechnology company focused on the discovery, ... that patient enrollment in its ongoing randomized HOPE-Duchenne ... exceeded 50% of its 24-patient target. Capricor expects ... third quarter of 2016, and to report top ...
(Date:6/23/2016)... INDIANAPOLIS , June 23, 2016 If ... Leaders Scholarship is any indication, the future is in ... at by the Diabetes Scholars Foundation ... the way of academic and community service excellence. ... since 2012, and continues to advocate for people with ...
Breaking Medicine Technology: