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

Video Protests Continue in Ferguson, Spread to Other US Cities

Missouri officials say deployment of more than 2,000 National Guard soldiers helps curb second night of rampant arson and looting in Midwestern town More

Video Ebola, Crackdown on Illegals Hit Business in Guangzhou

Chinese city has largest community of Africans in Asia More

Video Legendary Lebanese Actress, Singer Sabah Dies at 87

Music and film diva, affectionately called 'Sabbouha' by millions of her fans, performed at Carnegie Hall in New York, Royal Albert Hall in London, Olympia in Paris, Sydney Opera House in Sydney 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.
Aung San Suu Kyi: Myanmar Opposition to Keep Pushing for Constitutional Changei
X
November 24, 2014 10:09 PM
Myanmar opposition leader Aung San Suu Kyi says she and her supporters will continue pushing to amend a constitutional clause that bars her from running for president next year. VOA's Than Lwin Htun reports from the capital Naypyitaw in this report narrated by Colin Lovett.
Video

Video Aung San Suu Kyi: Myanmar Opposition to Keep Pushing for Constitutional Change

Myanmar opposition leader Aung San Suu Kyi says she and her supporters will continue pushing to amend a constitutional clause that bars her from running for president next year. VOA's Than Lwin Htun reports from the capital Naypyitaw in this report narrated by Colin Lovett.
Video

Video Mali Attempts to Shut Down Ebola Transmission Chain

Senegal and Nigeria were able to stop small Ebola outbreaks by closely monitoring those who had contact with the sick person and quickly isolating anyone with symptoms. Mali is now scrambling to do the same. VOA’s Anne Look reports from Mali on what the country is doing to shut down the chain of transmission.
Video

Video Ukraine Marks Anniversary of Deadly 1930s Famine

During a commemoration for millions who died of starvation in Ukraine in the early 1930s, President Petro Poroshenko lashed out at Soviet-era totalitarianism for causing the deaths and accused today’s Russian-backed rebels in the east of using similar tactics. VOA’s Daniel Shearf reports from Kyiv.
Video

Video Hong Kong Protests at a Crossroads

New public opinion polls in Hong Kong indicate declining support for pro-democracy demonstrations after weeks of street protests. VOA’s Bill Ide in Guangzhou and Pros Laput in Hong Kong spoke with protesters and observers about whether demonstrators have been too aggressive in pushing for change.
Video

Video US Immigration Relief Imminent for Mixed-Status Families

Tens of thousands of undocumented immigrants in the Washington, D.C., area may benefit from a controversial presidential order announced this week. It's not a path to citizenship, as some activists hoped. But it will allow more immigrants who arrived as children or who have citizen children, to avoid deportation and work legally. VOA's Victoria Macchi talks with one young man who benefited from an earlier presidential order, and whose parents may now benefit after years of living in fear.
Video

Video New Skateboard Defies Gravity

A futuristic dream only a couple of decades ago, the hoverboard – a skateboard that floats above the ground - has finally been made possible. While still not ready for mass production, it promises to become a cool mode of transport... at least over some surfaces. VOA’s George Putic reports.
Video

Video Falling Gas Prices Impact US Oil Extraction

With the price of oil now less than $80 a barrel, motorists throughout the United States are benefiting from gas prices below $3 a gallon. But as VOA’s Kane Farabaugh reports, the decreasing price of petroleum has a downside for the hydraulic fracturing industry in the United States.
Video

Video Tensions Build on Korean Peninsula Amid Military Drills

It has been another tense week on the Korean peninsula as Pyongyang threatened to again test nuclear weapons while the U.S. and South Korean forces held joint military exercises in a show of force. VOA’s Brian Padden reports from the Kunsan Air Base in South Korea.
Video

Video Mama Sarah Obama Honored at UN Women’s Entrepreneurship Day

President Barack Obama's step-grandmother is in the United States to raise money to build a $12 million school and hospital center in Kogelo, Kenya, the birthplace of the president's father, Barack Obama, Sr. She was honored for her decades of work to aid poor Kenyans at a Women's Entrepreneurship Day at the United Nations.
Video

Video Ebola Economic Toll Stirs W. Africa Food Security Concerns

The World Bank said Wednesday that it expects the economic impact of the Ebola outbreak on the sub-Saharan economy to cost somewhere betweenf $3 billion to $4 billion - well below a previously-outlined worst-case scenario of $32 billion. Some economists, however, paint a gloomier picture - warning that the disruption to regional markets and trading is considerable. Henry Ridgwell reports from London.
Video

Video Chaos, Abuse Defy Solution in Libya

The political and security crisis in Libya is deepening, with competing governments and, according to Amnesty International, widespread human rights violations committed with impunity. VOA’s Al Pessin reports from London.
Video

Video US Hosts Record 866,000 Foreign Students

Close to 900,000 international students are studying at American universities and colleges, more than ever before. About half of them come from Asia, mostly China. The United States hosts more foreign students than any other country in the world, and its foreign student population is steadily growing. Zlatica Hoke reports.

All About America

AppleAndroid