News / Africa

    HIV Transmitted During Sex May Hold Clues to Infection

    Multimedia

    Audio
    Joe DeCapua

    HIV / GENITAL TRACT -- A new study finds the AIDS virus circulating in the blood may be very different from the virus that’s transmitted during sex.  And this could have implications in the search for an effective vaccine or microbicide.

    University of North Carolina School of Medicine researchers at Chapel Hill say HIV may undergo changes in the genital tract of men.  As a result, the virus contained in semen could hold clues about how to block infection.  More research is needed, however.

    Why important

    “Most of what we know about HIV is based on analysis of virus that’s in the blood.  And much of the transmission that goes on goes from men to women or men to men.  But the male genital tract, male seminal tract, is involved in those transmissions,” says Ron Swanstrom, professor of biochemistry at UNC and the senior author of the study.

    “Anything that makes the virus different in semen, which is the site of the transmitted virus, becomes important to understand just to find out if it’s relevant to the transmission event,” he adds.

    Do researchers know why HIV can change in the seminal tract?  “That’s the big question for us,” he says, “and no.”

    It could be one of two reasons.

    Swanstrom says, “There’s a phenomenon known called the founder’s effect where…by chance it’s one thing that gets started and it grows from that….  So it could be just by luck that one or a few viruses get established in the seminal tract and grow out .  In which case presumably there won’t be any differences in terms of the biology of the virus compared to what’s in the blood.”

    On the other hand, there’s another, more important possibility.

    “There could be some selective pressure.  That the virus that grows in the seminal tract has some other different set of circumstances that it deals with and has to adapt to that environment.  And therefore, it’s a little bit different than what’s in the blood,” he says.

    What’s the difference?

    Much of the time HIV in the semen and HIV in the blood may not differ at all.  But other times there may be two different scenarios.

    Professor Ron Swanstrom
    Professor Ron Swanstrom

    “One virus or a couple of viruses seem to take off over a very short period of time and represent a significant fraction of the virus in the semen.  We don’t know why that happens, but it’ll be a much less complex population.  The population of the blood is very complex genetically.  The viruses are all kind of different from each other.  Suddenly the semen looks much more homogeneous,” he says.

    Those particular viruses, however, disappear fairly quickly.  Another possibility, he says, is that the virus gets established in the seminal tract and eventually becomes separated from the HIV population in the blood.

    “That’s when we see this strong compartmentalization where the virus is very different.  But again, we don’t know what that difference is at this time,” he says.

    Vaccines, microbicides

    At this stage, it’s unclear whether the finding will affect vaccine and microbicide research.  But Swanstrom says, “If this is the pool of viruses that are being transmitted, then it’s really the virus that we want to understand the most about.”

    He cautions that while the differences can be seen at the genome level, they may not have any biological difference from the HIV in the blood and therefore won’t behave any differently.

    “But if they do confer some special property, then we certainly need to know about that. If we were really lucky, it might help inform us on either a vaccine or a more efficacious microbicide,” he says.

    It’s just a different kind of virus

    “I think that’s fair to say.  I’ve been a virologist for a long time and probably what’s different about HIV is that it grows constantly in the host.  And this is also true for HCV (Hepatitis C Virus).”

    The biochemistry professor says these are special viruses in that “they know how to survive in the face of our immune system.  For HIV it’s always evolving.  The virus is growing every day.”

    The HIV lifecycle is only about a day long.  “So 365 times a year it divides.  It grows.  If you think about that in terms of generations and how long it would be to have 365 generations of a person, that gets compressed into every year for HIV.  And whatever the host is able to throw at it, it evolves away from it.  And so there’s this titanic battle that goes on constantly between the virus and the host,” he says.

    The next step is to clone the HIV found in the semen and study it further to learn whether its difference will make a difference in the search for better treatment or a cure.

    You May Like

    Republicans Struggle With Reality of Trump Nomination

    Despite calls for unity by presumptive presidential nominee, analysts see inevitable fragmentation of party ahead of November election and beyond

    Nielsen's, Sina Weibo Team Up for Closer Look at Chinese Social Media

    US-based rating agency reaches deal with China's Twitter-like service to gauge marketing effectiveness on platform which has more than 200 million users

    Despite Cease-fire, Myanmar Landmine Scourge Goes Unaddressed

    Myanmar has third-highest mine casualty rate in the world, according to Landmine and Cluster Munition Monitor, which says between 1999 to 2014 it recorded 3,745 casualties, 396 of whom died

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

    By the Numbers

    Featured Videos

    Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
    Press Freedom in Myanmar Fragile, Limitedi
    X
    Katie Arnold
    May 04, 2016 12:31 PM
    As Myanmar begins a new era with a democratically elected government, many issues of the past confront the new leadership. Among them is press freedom in a country where journalists have been routinely harassed or jailed.
    Video

    Video Press Freedom in Myanmar Fragile, Limited

    As Myanmar begins a new era with a democratically elected government, many issues of the past confront the new leadership. Among them is press freedom in a country where journalists have been routinely harassed or jailed.
    Video

    Video Taliban Threats Force Messi Fan to Leave Afghanistan

    A young Afghan boy, who recently received autographed shirts and a football from his soccer hero Lionel Messi, has fled his country due to safety concerns. He and his family are now taking refuge in neighboring Pakistan. VOA's Ayaz Gul reports from Islamabad.
    Video

    Video Major Rubbish Burning Experiment Captures Destructive Greenhouse Gases

    The world’s first test to capture environmentally harmful carbon dioxide gases from the fumes of burning rubbish took place recently in Oslo, Norway. The successful experiment at the city's main incinerator plant, showcased a method for capturing most of the carbon dioxide. VOA’s Deborah Block has more.
    Video

    Video EU Visa Block Threatens To Derail EU-Turkey Migrant Deal

    Turkish citizens could soon benefit from visa-free travel to Europe as part of the recent deal between the EU and Ankara to stem the flow of refugees. In return, Turkey has pledged to keep the migrants on Turkish soil and crack down on those who are smuggling them. Brussels is set to publish its latest progress report Wednesday — but as Henry Ridgwell reports from London, many EU lawmakers are threatening to veto the deal over human rights concerns.
    Video

    Video Tensions Rising Ahead of South China Sea Ruling

    As the Philippines awaits an international arbitration ruling on a challenge to China's claims to nearly all of the South China Sea, it is already becoming clear that regardless of which way the decision goes, the dispute is intensifying. VOA’s Bill Ide has more from Beijing.
    Video

    Video Painting Captures President Lincoln Assassination Aftermath

    A newly restored painting captures the moments following President Abraham Lincoln’s assassination in 1865. It was recently unveiled at Ford’s Theatre in Washington, where America’s 16th president was shot. It is the only known painting by an eyewitness that captures the horror of that fateful night. VOA’s Julie Taboh tells us more about the painting and what it took to restore it to its original condition.
    Video

    Video Elephant Summit Results in $5M in Pledges, Presidential Support

    Attended and supported by three African presidents, a three-day anti-poaching summit has concluded in Kenya, resulting in $5 million in pledges and a united message to the world that elephants are worth more alive than dead. The summit culminated at the Nairobi National Park with the largest ivory burn in history. VOA’s Jill Craig attended the summit and has this report about the outcomes.
    Video

    Video Displaced By War, Syrian Artist Finds Inspiration Abroad

    Saudi-born Syrian painter Mohammad Zaza is among the millions who fled their home for an uncertain future after Syria's civil war broke out. Since fleeing Syria, Zaza has lived in Lebanon, Egypt, Jordan and now Turkey where his latest exhibition, “Earth is Blue like an Orange,” opened in Istanbul. He spoke with VOA about how being displaced by the Syrian civil war has affected the country's artists.
    Video

    Video Ethiopia’s Drought Takes Toll on Children

    Ethiopia is dealing with its worst drought in decades, thanks to El Nino weather patterns. An estimated 10 million people urgently need food aid. Six million of them are children, whose development may be compromised without sufficient help, Marthe van der Wolf reports for VOA from the Metahara district.
    Video

    Video Little Havana - a Slice of Cuban Culture in Florida

    Hispanic culture permeates everything in Miami’s Little Havana area: elderly men playing dominoes as they discuss politics, cigar rollers deep at work, or Cuban exiles talking with presidential candidates at a Cuban coffee window. With the recent rapprochement between Cuba and United States, one can only expect stronger ties between South Florida and Cuba.
    Video

    Video California Republicans Weigh Presidential Choices Amid Protests

    Republican presidential candidates have been wooing local party leaders in California, a state that could be decisive in selecting the party's nominee for U.S. president. VOA's Mike O’Sullivan reports delegates to the California party convention have been evaluating choices, while front-runner Donald Trump drew hundreds of raucous protesters Friday.
    Video

    Video ‘The Lights of Africa’ - Through the Eyes of 54 Artists

    An exhibition bringing together the work of 54 African artists, one from each country, is touring the continent after debuting at COP21 in Paris. Called "Lumières d'Afrique," the show centers on access to electricity and, more figuratively, ideas that enlighten. Emilie Iob reports from Abidjan, the exhibition's first stop.

    Special Report

    Adrift The Invisible African Diaspora