Free Newsletters - Space - Defense - Environment - Energy - Solar - Nuclear
..
. Earth Science News .




EPIDEMICS
New bird flu strain seen adapting to mammals, humans
by Staff Writers
Madison WI (SPX) Apr 18, 2013


Influenza virus depends on its ability to attach to and commandeer the living cells of its host to replicate and spread efficiently. Avian influenza rarely infects humans, but can sometimes adapt to people, posing a significant risk to human health.

A genetic analysis of the avian flu virus responsible for at least nine human deaths in China portrays a virus evolving to adapt to human cells, raising concern about its potential to spark a new global flu pandemic.

The collaborative study, conducted by a group led by Masato Tashiro of the Influenza Virus Research Center, National Institute of Infectious Diseases, and Yoshihiro Kawaoka of the University of Wisconsin-Madison and the University of Tokyo, appears in the current edition of the journal Eurosurveillance.

The group examined the genetic sequences of H7N9 isolates from four of the pathogen's human victims as well as samples derived from birds and the environs of a Shanghai market.

"The human isolates, but not the avian and environmental ones, have a protein mutation that allows for efficient growth in human cells and that also allows them to grow at a temperature that corresponds to the upper respiratory tract of humans, which is lower than you find in birds," says Kawaoka, a leading expert on avian influenza.

The findings, drawn from genetic sequences deposited by Chinese researchers into an international database, provide some of the first molecular clues about a worrisome new strain of bird flu, the first human cases of which were reported on March 31 by the Chinese Center for Disease Control and Prevention.

So far, the new virus has sickened at least 33 people, killing nine. Although it is too early to predict its potential to cause a pandemic, signs that the virus is adapting to mammalian and, in particular, human hosts are unmistakable, says Kawaoka.

Access to the genetic information in the viruses, he adds, is necessary for understanding how the virus is evolving and for developing a candidate vaccine to prevent infection.

Influenza virus depends on its ability to attach to and commandeer the living cells of its host to replicate and spread efficiently. Avian influenza rarely infects humans, but can sometimes adapt to people, posing a significant risk to human health.

"These viruses possess several characteristic features of mammalian influenza viruses, which likely contribute to their ability to infect humans and raise concerns regarding their pandemic potential," Kawaoka and his colleagues conclude in the Eurosurveillance report.

Kawaoka, a faculty member in the UW-Madison School of Veterinary Medicine who also holds a faculty appointment at the University of Tokyo, explains that the majority of the viruses in the study - from both humans and birds - display mutations in the surface protein hemagglutinin, which the pathogen uses to bind to host cells. Those mutations, according to Kawaoka, allowed them to easily infect human cells.

In addition, the isolates from patients contained another mutation that allows the virus to efficiently replicate inside human cells. The same mutation, Kawaoka notes, lets the avian virus thrive in the cooler temperatures of the human upper respiratory system. It is in the cells of the nose and throat that flu typically gains a hold in a mammalian or human host.

Kawaoka and his colleagues also assessed the response of the new strain to drugs used to treat influenza, discovering that one class of commonly used antiviral drugs, ion channel inhibitors which effectively bottle up the virus in the cell, would not be effective; the new strain could be treated with another clinically relevant antiviral drug, oseltamivir.

In addition to Kawaoka and Tashiro, co-authors of the Eurosurveillance report include Tsutomu Kageyama, Seiichiro Fujisaki, Emi Takashita, Hong Xu, Shinya Yamada, Yuko Uchida, Gabriele Neumann and Takehiko Saito. The work was supported by Grants-in-Aid for Pandemic Influenza Research and Grant-in-Aid for Specially Promoted Research from the Ministry of Health, Labour and Welfare, Japan; by the NIAID Center for Research on Influenza Pathogenesis (CRIP, HHSN266200700010C); by a Grant-in-Aid for Specially Promoted Research, by the Japan Initiative for Global Research Network on Infectious Diseases from the Ministry of Education, Culture, Sports, Science, and Technology, Japan; and by ERATO, Japan.

.


Related Links
University of Wisconsin-Madison
Epidemics on Earth - Bird Flu, HIV/AIDS, Ebola






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News





EPIDEMICS
Beijing H7N9 bird flu victim leaves hospital
Beijing (AFP) April 17, 2013
A seven-year-old girl who contracted the H7N9 strain of bird flu left hospital on Wednesday and appeared before media in an apparent bid by health authorities to cool concerns about the deadly virus. The daughter of poultry traders was Beijing's first confirmed human case of the virus, which has killed 17 people and infected scores of people hundreds of miles (kilometres) away in eastern Chi ... read more


EPIDEMICS
Fukushima leaking radioactive water

IAEA begins fresh probe into Japan's Fukushima

Fukushima plant springs another radioactive leak

Hong Kong ferry crash captains face manslaughter charges

EPIDEMICS
Softening steel problem expands computer model applications

New material gets itself into shape

For the very first time, two spacecraft will fly in formation with millimeter precision

High pressure gold nanocrystal structure revealed

EPIDEMICS
Study reveals seasonal patterns of tropical rainfall changes from global warming

Liverpool Bay sediment discovery could save millions

Mass sea lion strandings baffle California

Cutting specific pollutants would slow sea level rise

EPIDEMICS
New insight into accelerating summer ice melt on the Antarctic Peninsula

Recent climate, glacier changes in Antarctica at the 'upper bound' of normal

Austria's glaciers shrank in 2012: study

New chart shows the entire topography of the Antarctic seafloor in detail

EPIDEMICS
Virginia Tech research team creates potential food source from non-food plants

Egypt faces food crisis over wheat shortage

Chickens with bigger gizzards are more efficient

Hundreds of pigs, dogs die in Chinese city: officials

EPIDEMICS
Research aims to settle debate over origin of Yellowstone volcano

'Thousands' of Pakistanis affected by Iran quake

US offers aid as Iran quake kills 34 in Pakistan

Japan island rocked by 30 quakes

EPIDEMICS
Radical Nigeria cleric rejects place on amnesty panel

Zimbabwe deputy PM tells Africa to be tough on China

Nigeria moves closer to amnesty offer for Islamists

Chad quits Mali war, French stick it out

EPIDEMICS
New Research Reveals How Human Ancestor Walked, Chewed, and Moved

Pottery reveals Ice Age hunter-gatherers' taste for fish

Google adds 'digital estate planning' to its services

Better Understanding of Human Brain Supports National Security




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement