News / Science & Technology

    Study Identifies Risks of Human Spread of H7N9 Bird Flu

    Authorities are taking samples of live poultry from mainland China to test for the H7N9 virus, April 11, 2013.
    Authorities are taking samples of live poultry from mainland China to test for the H7N9 virus, April 11, 2013.
    Jessica Berman
    A new study finds that the recently discovered H7N9 bird flu virus, which has been circulating among poultry flocks in eastern China, can be transmitted among ferrets, small mammals that provide a laboratory model for human contagion.  Since the H7N9 virus was first identified in China last February, there have been 132 human infections confirmed in China and one in Taiwan, with a total of 36 deaths.  While there have been concerns that this bird flu could become a global pandemic, the new study suggests that the virus could spread among people.

    So far, it appears that people who have been diagnosed with the H7N9 virus have all had close contact with infected birds, primarily in live poultry markets.  To become a pandemic, the avian virus would have to spread easily from human-to-human.

    To find out how efficiently the virus can be transmitted among humans, an international team of researchers, led by Chinese scientists, studied its contagion among ferrets. The small mammals can transmit infectious diseases through aerosols produced by sneezing and coughing, much like humans.

    Richard Webby is a virologist at St. Jude Children’s Research Hospital in Memphis, Tennessee and a study co-author.  Webby said the work seems to suggest humans would have to be in close contact to transmit this virus. “That’s what our ferret studies would support. That potentially, if you have infected people very close to uninfected people, you might get transmission," he explained. "But it’s not very efficient.”

    Chinese investigators swabbed the noses of a group of ferrets infected with the H7N9 virus taken from an infected human patient who had died. Researchers detected evidence of H7 through the nasal samples before the animals developed respiratory symptoms, suggesting more people may be carriers of the virus than is currently believed.  

    The disease was also transmitted to uninfected ferrets through direct contact with infected animals in the same cage, simulating what might happen among human family members living in the same home.

    But when they were placed in a separate cage and exposed to diseased animals in another enclosure, only 1 of 3 healthy ferrets contracted H7N9.  Researchers also found the virus did not transmit to pigs, another potential reservoir of influenza.

    Experts believe both airborne and direct contact transmission is needed to ignite a pandemic.
     
    Anthony Fauci is director of the US National Institute of Allergy and Infectious Diseases.  Fauci said the findings of the Chinese study confirm what's already known about H7N9. "That it can be transmitted to mammals rarely and inefficiently, and it's not being transmitted in any way from person to person," he stated.

    Meanwhile, in the first human population study of H7N9 influenza, researchers analyzed just over 1,700 blood samples for 5 different avian flu viruses in the H7 subtype, in both urban and rural areas in southern Vietnam, which neighbors China.  

    Investigators found low levels of H7 antibodies, markers of the human immune system's ability to defend against pathogens. The researchers say the low levels suggest that international measures to contain the H7N9 influenza, in the event of severe outbreak, will need to be targeted in Asia.

    The Chinese transmissibility study recommends that to avoid H7N9 becoming endemic in poultry populations -- a development that would create new opportuinities for human transmission, live poultry markets in the region must be more carefully and strictly managed.

    Their research is published in the journal Science Express.

    You May Like

    Turkey, US Splits Deepen Over Support for Kurdish Militants

    Ankara summons American ambassador to protest remarks by State Department spokesman who said Washington does not consider Syria's Kurdish Democracy Union Party (PYD) a terrorist organization

    Obama Seeking $19 Billion for National Cybersecurity

    Move, touted as attempt to build broad, cohesive federal response to cyberthreats, calls for increase in cybersecurity spending across all government agencies

    Video Foreign Policy Weighs Heavy for Some US Voters

    VOA talks to protesters in Manchester, New Hampshire, who sound off on foreign policy issues such as the Guantanamo Bay prison, the Israeli-Palestinian conflict and the wars in Iraq, Syria and Yemen

    Featured Videos

    Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
    Valentine's Day Stinks for Lebanese Clownsi
    X
    February 09, 2016 8:04 PM
    This weekend, on Valentine's Day in Lebanon, love is not the only thing in the air. More than half a year after the country's trash crisis began, the stink of uncollected garbage remains on the streets. Step forward "Clown Me In," a group of clowns who use their skills for activism. Before the most romantic day of the year the clowns have released their unusual take on love in Lebanon -- in a bid to keep the pressure up and get the trash off the streets. John Owens reports from Beirut.
    Video

    Video Valentine's Day Stinks for Lebanese Clowns

    This weekend, on Valentine's Day in Lebanon, love is not the only thing in the air. More than half a year after the country's trash crisis began, the stink of uncollected garbage remains on the streets. Step forward "Clown Me In," a group of clowns who use their skills for activism. Before the most romantic day of the year the clowns have released their unusual take on love in Lebanon -- in a bid to keep the pressure up and get the trash off the streets. John Owens reports from Beirut.
    Video

    Video Rocky Year Ahead for Nigeria Amid Oil Price Crash

    The global fall in the price of oil has rattled the economies of many petroleum exporters, and Africa’s oil king Nigeria is no exception. As Chris Stein reports from Lagos, analysts are predicting a rough year ahead for the continent’s top producer of crude.
    Video

    Video Foreign Policy Weighs Heavy for Some US Voters

    VOA talks to protesters in Manchester, New Hampshire who sound off on foreign policy issues such as the Guantanamo Bay Prison, the Israeli-Palestinian conflict, Middle East Affairs and national security.
    Video

    Video 'No Means No' Program Targets Sexual Violence in Kenya

    The organizers of an initiative to reduce and stop rape in the informal settlements around Kenya's capital say their program is having marked success. Girls are taking self-defense classes while the boys are learning how to protect the girls and respect them. Lenny Ruvaga reports from Nairobi.
    Video

    Video New Hampshire Voters Are Independent, Mindful of History

    Once every four years, the northeastern state of New Hampshire becomes the center of the U.S. political universe with its first-in-the-nation presidential primary. What's unusual about New Hampshire is how seriously the voters take their role and the responsibility of being among the first to weigh in on the candidates.
    Video

    Video Chocolate Lovers Get a Sweet History Lesson

    Observed in many countries around the world, Valentine’s Day is sometimes celebrated with chocolate festivals. But at a festival near Washington, the visitors experience a bit more than a sugar rush. They go on a sweet journey through history. VOA’s June Soh takes us to the festival.
    Video

    Video 'Smart' Bandages Could Heal Wounds More Quickly

    Simple bandages are usually seen as the first line of attack in healing small to moderate wounds and burns. But scientists say new synthetic materials with embedded microsensors could turn bandages into a much more valuable tool for emergency physicians. VOA’s George Putic reports.
    Video

    Video Bhutanese Refugees in New Hampshire Closely Watching Primary Election

    They fled their country and lived in refugee camps in neighboring Nepal for decades before being resettled in the northeastern U.S. state of New Hampshire -- now the focus of the U.S. presidential contest. VOA correspondent Aru Pande spoke with members of the Bhutanese community, including new American citizens, about the campaign and the strong anti-immigrant rhetoric of some of the candidates.
    Video

    Video Researchers Use 3-D Printer to Produce Transplantable Body Parts

    Human organ transplants have become fairly common around the world in the past few decades. Researchers at various universities are coordinating their efforts to find solutions -- including teams at the University of Pennsylvania and Rice University in Houston that are experimenting with a 3-D printer -- to make blood vessels and other structures for implant. As VOA’s Greg Flakus reports from Houston, they are also using these artificial body parts to seek ways of defeating cancerous tumors.
    Video

    Video Helping the Blind 'See' Great Art

    There are 285 million blind and visually impaired people in the world who are unable to enjoy visual art at a museum. One New York photographer is trying to fix this situation by making tangible copies of the world’s masterpieces. VOA correspondent Victoria Kupchinetsky was there as visually impaired people got a feel for great art. Joy Wagner narrates her report.
    Video

    Video German Artists to Memorialize Refugees With Life Jacket Exhibit

    Sold in every kind of shop in some Turkish port towns, life jackets have become a symbol of the refugee crisis that brought a million people to Europe in 2015.  On the shores of Lesbos, Greece, German artists collect discarded life jackets as they prepare an art installation they plan to display in Germany.  For VOA, Hamada Elrasam has this report from Lesbos, Greece.
    Video

    Video E-readers Help Ease Africa's Book Shortage

    Millions of people in Africa can't read, and there's a chronic shortage of books. A non-profit organization called Worldreader is trying to help change all that one e-reader at a time. VOA’s Deborah Block tells us about a girls' school in Nairobi, Kenya where Worldreader is making a difference.
    Video

    Video Genius Lets World Share Its Knowledge

    Inspired by crowdsourcing companies like Wikipedia, Genius allows anyone to edit anything on the web, using its web annotation tool
    Video

    Video In Philippines, Mixed Feelings About Greater US Military Presence

    In the Philippines, some who will be directly affected by a recent Supreme Court decision clearing the way for more United States troop visits are having mixed reactions.  The increased rotations come at a time when the Philippines is trying to build up its military in the face of growing maritime assertiveness from China.  From Bahile, Palawan on the coast of the South China Sea, Simone Orendain has this story.