News / Health

    Scientists Race to Assess New Bird Flu's Pandemic Risk

    Technicians carry out a test for the H7N9 bird flu virus using test reagents at the Beijing Center for Diseases Control and Prevention in Beijing, April 3, 2013. (Reuters)
    Technicians carry out a test for the H7N9 bird flu virus using test reagents at the Beijing Center for Diseases Control and Prevention in Beijing, April 3, 2013. (Reuters)
    Reuters
    Genetic sequence data on a deadly strain of bird flu previously unknown in people show the virus has already acquired some mutations that might make it more likely to cause a human pandemic, scientists say.

    But there is no evidence so far that the H7N9 flu - now known to have infected nine people in China, killing three - is spreading from person to person, and there is still a chance it might peter out and never fully mutate into a human form of flu.

    Just days after authorities in China announced they had identified cases of H7N9, flu experts in laboratories across the world are picking through the DNA sequence data of samples isolated from the patients to assess its pandemic potential.

    One of the world's top flu experts, Ab Osterhaus, who is based at the Erasmus Medical Centre in The Netherlands, said the sequences show some genetic mutations that should put authorities on alert and entail increased surveillance in animals and humans.

    "The virus has to a certain extent already adapted to mammalian species and to humans, so from that point of view it's worrisome," he told Reuters in a telephone interview. "Really we should keep a very close eye on this."

    New cases

    China's National Health and Family Planning Commission confirmed on Sunday that three people had been infected with the new H7N9 flu, with two deaths of men in Shanghai aged 87 and 27 who fell sick in late February. Chinese authorities have in the past two days confirmed another six cases, including another fatal one.

    The World Health Organization [WHO] says the cases of H7N9 are "of concern" because they are the first in humans.

    "That makes it a unique event, which the World Health Organization is taking seriously,'' the Geneva-based United Nations health agency said on Wednesday.

    Other strains of bird flu, such as H5N1, have been circulating for many years and can be transmitted from bird to bird, and bird to human, but not from human to human.

    So far, this lack of human-to-human transmission also appears to be a feature of the H7N9 strain.

    Flu viruses are classified based on two types of protein found on their surface, haemagglutinin and neuraminidase, which are abbreviated to H and N.

    Although it is very early days, scientists say initial analysis also suggests H7N9 does not appear to make birds particularly ill - in other words it is what is known as a low pathogenic avian influenza, of LPAI.

    Unfortunately, this doesn't necessarily mean it will be mild in humans, says Wendy Barclay, a flu virology expert at Britain's Imperial College London.

    Finding the source

    "We can't be complacent. We have to be cautious," she said, stressing that other H5 and H7 flu subtypes have been able to mutate from LPAI to the more dangerous highly pathogenic avian influenza [HPAI] as they circulate in various hosts, particularly in chickens.

    Its mildness in birds could also mean H7N9 is a "silent spreader" - harder to detect than highly pathogenic flu strains such as H5N1 that can wipe out entire flocks of wild birds or domestic poultry and are therefore far more visible.

    "It's a sort of double-edged sword, because if and when it becomes highly pathogenic and all the chickens start dying, that's very bad for the poultry farmers, but it means we can see much more easily where the virus is," said Barclay.

    "At the moment, we can't see where this virus is coming from. We don't know yet what animal source is feeding this," she said.

    Finding that source, and tracking the genetic mutations to see if, how and when this new strain might gain the ability to spark a human pandemic are now the priorities for researchers in China and around the world, said Barclay and Osterhaus.

    China reacts

    The WHO praised the Chinese government, saying it was responding to the situation with various important measures such as enhanced surveillance, detailed case management and treatment, tracing contacts of all those known to have been infected so far, and training healthcare professionals.

    Experts said the fact that H7N9 had been identified and swiftly reported, and that genetic sequence data was already available for researchers around the world to analyze, was a sign of how things have changed.

    In 2003, China initially tried to cover up an epidemic of Severe Acute Respiratory Syndrome, which emerged in China and killed about a tenth of the 8,000 people it infected worldwide.

    Ian Jones, a professor of virology at Britain's University of Reading, said the heightened awareness of flu and of the possibility that unusual respiratory diseases may turn out to be new strains of flu means more cases get referred to hospitals.

    "It's quite possible these cases... are being detected because flu is way up there" on disease priority lists, he said.

    You May Like

    Chechen Suspected in Istanbul Attack, but Questions Remain

    Turkish sources say North Caucasus militants involved in bombing at Ataturk airport, but name of at least one alleged attacker raises doubts

    With Johnson Out, Can a New ‘Margaret Thatcher’ Save Britain?

    Contest to replace David Cameron as Britain’s prime minister started in earnest Thursday with top candidates outlining strategy to deal with Brexit fallout

    US Finds Progress Slow Against Human Trafficking in Africa

    Africa continues to be a major source and destination for human trafficking of all kinds -- from forced labor to sexual slavery, says State Department report

    Featured Videos

    Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
    Clinton Leads Trump, But Many Voters Don't Like Eitheri
    X
    Jim Malone
    June 29, 2016 6:16 PM
    In the U.S. presidential race, most recent polls show Democrat Hillary Clinton with a steady lead over Republican Donald Trump as both presumptive party nominees prepare for their party conventions next month. Trump’s disapproval ratings have risen in some recent surveys, but Clinton also suffers from high negative ratings, suggesting both candidates have a lot of work to do to improve their images before the November election. VOA National correspondent Jim Malone has more from Washington.
    Video

    Video Clinton Leads Trump, But Many Voters Don't Like Either

    In the U.S. presidential race, most recent polls show Democrat Hillary Clinton with a steady lead over Republican Donald Trump as both presumptive party nominees prepare for their party conventions next month. Trump’s disapproval ratings have risen in some recent surveys, but Clinton also suffers from high negative ratings, suggesting both candidates have a lot of work to do to improve their images before the November election. VOA National correspondent Jim Malone has more from Washington.
    Video

    Video Slow Rebuilding Amid Boko Haram Destruction in Nigeria’s Northeast

    Military operations have chased Boko Haram out of towns and cities in Nigeria’s northeast since early last year. But it is only recently that people have begun returning to their homes in Adamawa state, near the border with Cameroon, to try to rebuild their lives. For VOA, Chris Stein traveled to the area and has this report.
    Video

    Video New US Ambassador to Somalia Faces Heavy Challenges

    The new U.S. envoy to Somalia, who was sworn into office Monday, will be the first American ambassador to that nation in 25 years. He will take up his post as Somalia faces a number of crucial issues, including insecurity, an upcoming election, and the potential closure of the Dadaab refugee camp in Kenya. VOA’s Jill Craig asked Somalis living in Kenya’s capital city Nairobi how they feel about the U.S. finally installing a new ambassador.
    Video

    Video At National Zoo, Captivating Animal Sculptures Illustrate Tragedy of Ocean Pollution

    The National Zoo in Washington, D.C., is home to about 1,800 animals, representing 300 species. But throughout the summer, visitors can also see other kinds of creatures there. They are larger-than-life animal sculptures that speak volumes about a global issue — the massive plastic pollution in our oceans. VOA's June Soh takes us to the zoo's special exhibit, called Washed Ashore: Art to Save the Sea.
    Video

    Video Baghdad Bikers Defy War with a Roar

    Baghdad is a city of contradictions. War is a constant. Explosions and kidnappings are part of daily life. But the Iraqi capital remains a thriving city, even if a little beat up. VOA's Sharon Behn reports on how some in Baghdad are defying the stereotype of a nation at war by pursuing a lifestyle known for its iconic symbols of rebellion: motorbikes, leather jackets and roaring engines.
    Video

    Video Melting Pot of Immigrants Working to Restore US Capitol Dome

    The American Iron Works company is one of the firms working to renovate the iconic U.S. Capitol Dome. The company employs immigrants of many different cultural and national backgrounds. VOA’s Arman Tarjimanyan has more.
    Video

    Video Testing Bamboo as Building Material

    For thousands of years various species of bamboo - one of the world's most versatile plants - have been used for diverse purposes ranging from food and medicine to textiles and construction. But its use on a large scale is hampered because it's not manufactured to specific standards but grown in the ground. A University of Pittsburgh professor is on track to changing that. VOA’s George Putic reports.
    Video

    Video Orphanage in Iraqi City Houses Kids Who Lost their Parents to Attacks by IS

    An orphanage in Iraqi Kurdistan has become home to scores of Yazidi children who lost their parents after Islamic State militants took over Sinjar in Iraq’s Nineveh Province in 2014. Iraqi Kurdish forces backed by the U.S. airstrikes have since recaptured Sinjar but the need for the care provided by the orphanage continues. VOA’s Kawa Omar filed this report narrated by Rob Raffaele.
    Video

    Video Re-Opening Old Wounds in a Bullet-Riddled Cultural Landmark

    A cultural landmark before Lebanon’s civil war transformed it into a nest of snipers, Beirut’s ‘Yellow House’ is once again set to play a crucial role in the city.  Built in a neo-Ottoman style in the 1920s, in September it is set to be re-opened as a ‘memory museum’ - its bullet-riddled walls and bunkered positions overlooking the city’s notorious ‘Green Line’ maintained for posterity. John Owens reports from Beirut.
    Video

    Video Brexit Resounds in US Presidential Contest

    Britain’s decision to leave the European Union is resounding in America’s presidential race. As VOA’s Michael Bowman reports, Republican presumptive nominee Donald Trump sees Britain’s move as an affirmation of his campaign’s core messages, while Democrat Hillary Clinton sees the episode as further evidence that Trump is unfit to be president.
    Video

    Video NASA Juno Spacecraft, Nearing Jupiter, to Shed Light on Gas Giant

    After a five-year journey, the spacecraft Juno is nearing its destination, the giant planet Jupiter, where it will enter orbit and start sending data back July 4th. As Mike O'Sullivan reports from Pasadena, California, the craft will pierce the veil of Jupiter's dense cloud cover to reveal its mysteries.
    Video

    Video Orlando Shooting Changes Debate on Gun Control

    It’s been nearly two weeks since the largest mass shooting ever in the United States. Despite public calls for tighter gun control laws, Congress is at an impasse. Democratic lawmakers resorted to a 1960s civil rights tactic to portray their frustration. VOA’s Carolyn Presutti explains how the Orlando, Florida shooting is changing the debate.

    Special Report

    Adrift The Invisible African Diaspora