News / Health

China Bird Flu Analysis Finds More Virus Threats Lurking

This undated handout image provided by Science and the University of Tokyo shows infectious particles of the avian H7N9 virus emerging from a cell.
This undated handout image provided by Science and the University of Tokyo shows infectious particles of the avian H7N9 virus emerging from a cell.
Reuters
— A deadly new bird flu virus in China evolved from migratory birds via waterfowl to poultry and into people, and there are other bird flu viruses circulating that could follow the same path, scientists have found.
 
The study - an analysis of the evolutionary history of the H7N9 bird flu that has so far killed 44 people - identified several other H7 flu viruses circulating in birds that the researchers said “may pose threats beyond the current outbreak”.
 
While none of the additional H7 strains they detected has yet been found in humans, some are able to infect other mammals such as ferrets, the researchers said, suggesting a jump to humans may be possible.
 
“The discovery ... reminds us that even if H7N9 does not return, there are risks lurking amongst the great diversity of avian influenza viruses,” said Peter Horby, a bird flu expert at the Oxford University Clinical Research Unit in Hanoi, Vietnam, who was not involved in the research.
 
H7N9 bird flu, which was unknown in humans until February, has so far infected at least 135 people in China and Taiwan, killing 44 of them, according to the latest World Health Organization (WHO) data.
 
Most cases have been in people who had visited live poultry markets or had close contact with live poultry.
 
In recent weeks the number of new infections in people has dropped dramatically, thanks largely, experts say, to the closure by Chinese authorities of many live poultry markets and the summer season. But many virologists fear the human case rate may pick up again with the return of autumn and winter in China.
 
To trace the evolution of H7N9 and its path into humans, researchers led by Maria Huachen Zhu and Yi Guan of the University of Hong Kong conducted field surveillance around the main H7N9 outbreak region and mapped out, or sequenced, genetic codes of a large number of bird flu viruses they found.
 
Reporting their findings in the journal Nature on Wednesday, they concluded that H7 viruses probably transferred from ducks to chickens on at least two independent occasions and that a so-called “reassortment” of these viruses with others called H9N2 eventually generated the H7N9 outbreak virus.
 
They also found another previously unrecognized H7N7 virus strain had emerged and is circulating in poultry in China.
 
In experiments testing this strain, they discovered it has the ability to infect ferrets - an animal model often used by scientists to find out more about what flu might do in humans - suggesting it could jump into people in future.
 
Flu experts praised the research, with Horby describing it as using the kind of “microbial forensics” essential for helping scientists piece together where new bird flu viruses come from and what other threats might be out there.
 
Ian Jones, a virologist at Britain's University of Reading, said the discovery of other H7 bird flu strains was interesting but stressed they were “not of immediate public concern”.
 
“The study identifies the route of adaptation [for H7N9] from migratory birds to local waterfowl to poultry in live markets and then to people,” he said. “Surveillance programs can now focus on key strains in the adaption process and eradicate them before they complete the jump to people.”

You May Like

Reports of Mass Murder on Mediterranean Smuggler’s Boat

Boat sailed from Libya with 750 migrants aboard and arrived in Italy with 569 More

Video New Thailand Hotline Targets Misbehaving Monks

Officials say move aims to restore country’s image of Buddhism, tarnished by recent high profile scandals such as opulent lifestyle, drug and alcohol abuse, as well as child sex abuse More

Study: Dust from Sahara Helped Form Bahama Islands

What does the Sahara have in common with a Caribbean island? Quite a lot, researchers say More

Featured Videos

Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
Astronauts Train in Underwater Labi
X
George Putic
July 25, 2014 7:25 PM
In the world’s only underwater laboratory, four U.S. astronauts train for a planned visit to an asteroid. The lab - called Aquarius- is located five kilometers off Key Largo, in southern Florida. Living in close quarters and making excursions only into the surrounding ocean, they try to simulate the daily routine of a crew that will someday travel to collect samples of a rock orbiting far away from earth. VOA’s George Putic has more.
Video

Video Astronauts Train in Underwater Lab

In the world’s only underwater laboratory, four U.S. astronauts train for a planned visit to an asteroid. The lab - called Aquarius- is located five kilometers off Key Largo, in southern Florida. Living in close quarters and making excursions only into the surrounding ocean, they try to simulate the daily routine of a crew that will someday travel to collect samples of a rock orbiting far away from earth. VOA’s George Putic has more.
Video

Video Not Even Monks Spared From Thailand’s Junta-Backed Morality Push

With Thailand’s military government firmly in control after May’s bloodless coup, authorities are carrying out plans they say are aimed at restoring discipline, morality and patriotism to all Thais. The measures include a crackdown on illegal gambling, education reforms to promote students’ moral development, and a new 24-hour phone hotline for citizens to report misbehaving monks. Steve Sandford reports from Bangkok.
Video

Video Virtual Program Teaches Farming Skills

In a fast-changing world beset by unpredictable climate conditions, farmers cannot afford to ignore new technology. Researchers in Australia are developing an online virtual world program to share information about climate change and more sustainable farming techniques for sugar cane growers. As VOA's Zlatica Hoke reports, the idea is to create a wider support network for farmers.
Video

Video Airline Expert: Missile will Show Signature on Debris

The debris field from Malaysia Airlines Flight 17 is spread over a 21-kilometer radius in eastern Ukraine. It is expected to take investigators months to sort through the airplane pieces to learn about the missile that brought down the jetliner and who fired it. VOAs Carolyn Presutti explains how this work will be done.
Video

Video Treatment for Childhood Epilepsy Heats up Medical Marijuana Debate

In the United States, marijuana is classed as an illegal drug by the federal government. But nearly half the states have legalized it, to some degree. Proponents say some strains of marijuana might have exceptional health benefits, for treating pain or inflammation in chronic conditions such as cancer, multiple sclerosis and epilepsy. Shelley Schlender reports on a strain of medical marijuana developed in Colorado that is reputed to reduce seizures in childhood epilepsy
Video

Video Airbus Adds Metal 3D Printed Parts to New Jets

By the end of this year, European aircraft manufacturing consortium Airbus plans to deliver the first of its new, extra-wide-body passenger jets, the A350-XWB. Among other technological innovations, the new plane will also incorporate metal parts made in a 3-D printer. VOA's George Putic has more.
Video

Video AIDS Conference Welcomes Exciting Developments in HIV Treatment, Prevention

Significant strides have been made in recent years toward the treatment and prevention of HIV, the virus that causes AIDS. This year, at the International AIDS Conference, the AIDS community welcomed progress on a new pill that may prevent transmission of the deadly virus. VOA’s Anita Powell reports from Melbourne, Australia.
Video

Video IAEA: Iran Turns its Enriched Uranium Into Less Harmful Form

Iran has converted its stockpiles of enriched uranium into a less dangerous form that is more difficult to use for nuclear weapons, according to the United Nations’ Atomic Energy Agency. The move complies with an interim deal reached with Western powers on Iran's nuclear program last year, in exchange for easing of sanctions. Henry Ridgwell reports for VOA from London.

AppleAndroid