News / Health

High Levels of HIV in Genital Secretions Predict Infectiousness

Jessica Berman

A new study finds that when high concentrations of HIV, the AIDS virus, turn up in a person's genital secretions, there is a higher risk the virus will be transmitted to that person's heterosexual partner.   The discovery sheds new light on the biology of HIV infection.

For the past 20 years, AIDS researchers have looked at concentrations of HIV in genital secretions as a potential indicator of infectiousness.  But none of the studies has been large enough to reach any firm conclusions.

The latest study, headed by University of Washington in Seattle Assistant Professor of Global Health and Medicine Jared Baeten, involved more than 2,500 heterosexual couples in seven African countries.  In each couple, one partner was infected and the other was not.

Baeten says researchers followed the couples, more than 5,000 people in Botswana, Kenya, Rwanda, South Africa, Tanzania, Uganda and Zambia, for as long as two years, and counseled them on safe-sex practices.

Nevertheless, 46 women transmitted HIV to their uninfected male partners and 32 men eventually gave the virus to their HIV-negative female partners.

Baeten says researchers found that the higher the concentration of HIV in samples of vaginal secretions or male semen, the greater the risk of HIV transmission between the partners.

"The relationship was linear," noted Baeten.  "As the amount of HIV in the genital samples went up, the risk of transmission went up.  And this was true for transmission from women to men and men to women."

Baeten says researchers have known for the past decade there is a relationship between the amount of HIV in the blood of infected individuals and the risk of transmission.

Baeten notes, however, that throughout most of the world, the disease is not spread through contact with blood, but through sexual intercourse and contact with genital fluids.  

Baeten says blood concentrations of HIV can vary from day to day, and some infected individuals naturally have lower blood levels of the virus.  He says this led to another interesting finding.

"Levels of HIV in the genital tract predicted HIV risk even accounting for levels of HIV in blood, arguing that the levels in the genital tract, because those are the most close to where HIV occurs, are potentially the best marker for transmission risk," Baeten added.

Baeten says he expects the discovery's impact will be not in the clinic, but in the laboratory, where it could be a boon to researchers looking for ways to reduce HIV transmission.

"Researchers can test interventions that reduce the genital-HIV levels and understand that those would have a substantial effect in preventing HIV-transmission risk," Baeten explained.

An article on gauging HIV infection risk through levels of the virus in genital secretions is published in the journal Science Translational Medicine.

You May Like

Turbulent Transition Imperils Tunisia’s Arab Spring Gains

Critics say new anti-terrorism laws worsen Tunisia's situation while others put faith in country’s vibrant civil organizations, women’s movement More

Burundi’s Political Crisis May Become Humanitarian One

United Nations aid agencies issue warning as deadly violence sends tens of thousands fleeing More

Yemenis Adjust to Life Under Houthi Rule

Locals want warring parties to strike deal to stop bloodletting before deciding how country is governed More

This forum has been closed.
Comments
     
There are no comments in this forum. Be first and add one

Featured Videos

Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
Seoul Sponsors Korean Unification Fairi
X
Brian Padden
May 29, 2015 1:27 PM
With inter-Korean relations deteriorating over the North’s nuclear program, past military provocations and human rights abuses, many Koreans still hold out hope for eventual peaceful re-unification. VOA’s Brian Padden visited a “unification fair” held this week in Seoul, where border communities promoted the benefits of increased cooperation.
Video

Video Seoul Sponsors Korean Unification Fair

With inter-Korean relations deteriorating over the North’s nuclear program, past military provocations and human rights abuses, many Koreans still hold out hope for eventual peaceful re-unification. VOA’s Brian Padden visited a “unification fair” held this week in Seoul, where border communities promoted the benefits of increased cooperation.
Video

Video Purple Door Coffeeshop: Changing Lives One Cup at a Time

For a quarter of his life, Kevin Persons lived on the street. Today, he is working behind the counter of an espresso bar, serving coffee and working to transition off the streets and into a home. Paul Vargas reports for VOA.
Video

Video Modular Robot Getting Closer to Reality

A robot being developed at Carnegie Mellon University has evolved into a multi-legged modular mechanical snake, able to move over rugged surfaces and explore the surroundings. Scientists say such machines could someday help in search and rescue operations. VOA’s George Putic reports.
Video

Video Shanghai Hosts Big Consumer Electronics Show

Electronic gadgets are a huge success in China, judging by the first Asian Consumer Electronics Show, held this week in Shanghai. Over the course of two days, more than 20,000 visitors watched, tested and played with useful and some less-useful electronic devices exhibited by about 200 manufacturers. VOA’s George Putic has more.
Video

Video Forced to Return Home, Afghan Refugees Face Increased Hardship

Undocumented refugees returning to Afghanistan from Pakistan have no jobs, no support system, and no home return to, and international aid agencies say they and the government are overwhelmed and under-resourced. Ayesha Tanzeem has more from Kabul.
Video

Video Britain Makes Controversial Move to Crack Down on Extremism

Britain is moving to tighten controls on extremist rhetoric, even when it does not incite violence or hatred -- a move that some are concerned might unduly restrict basic freedoms. It is an issue many countries are grappling with as extremist groups gain power in the Middle East, fueled in part by donations and fighters from the West. VOA’s Al Pessin reports from London.
Video

Video 3D Printer Makes Replica of Iconic Sports Car

Cars with parts made by 3D printers are already on the road, but engineers are still learning about this new technology. While testing the possibility of printing an entire car, researchers at the U.S. Department of Energy recently created an electric-powered replica of an iconic sports roadster. VOA’s George Putic has more.
Video

Video Al-Shabab Recruitment Drive Still on In Kenya

The al-Shabab militants that have long battled for control of Somalia also have recruited thousands of young people in Kenya, leaving many families disconsolate. Mohammed Yusuf recently visited the Kenyan town of Isiolo, and met with relatives of those recruited, as well as a many who have helped with the recruiting.
Video

Video A Small Oasis on Kabul's Outskirts Provides Relief From Security Tensions

When people in Kabul want to get away from the city and relax, many choose Qargha Lake, a small resort on the outskirts of Kabul. Ayesha Tanzeem visited and talked with people about the precious oasis.
Video

Video Kenyans Lament Losing Sons to al-Shabab

There is agony, fear and lost hope in the Kenyan town of Isiolo, a key target of a new al-Shabab recruitment drive. VOA's Mohammed Yusuf visits Isiolo to speak with families and at least one man who says he was a recruiter.
Video

Video Scientists Say Plankton More Important Than Previously Thought

Tiny ocean creatures called plankton are mostly thought of as food for whales and other large marine animals, but a four-year global study discovered, among other things, that plankton are a major source of oxygen on our planet. VOA’s George Putic reports.
Video

Video Kenya’s Capital Sees Rise in Shisha Parlors

In Kenya, the smoking of shisha, a type of flavored tobacco, is the latest craze. Patrons are flocking to shisha parlors to smoke and socialize. But the practice can be addictive and harmful, though many dabblers may not realize the dangers, according to a new review. Lenny Ruvaga has more on the story for VOA from Nairobi, Kenya.

VOA Blogs