Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Evidence of host adaptation of avian-origin influenza A virus

A novel avian-origin reassortant influenza A (H7N9) virus emerged in China in February 2013, and is associated with severe lower respiratory tract diseases.

To date, more than 100 human cases of infection, including at least 20 deaths, have been reported in China. Three early cases of infection were described in Hangzhou, Zhejiang Province, China.

The general clinical features of the three patients were similar to the previously reported cases in China. Two of the three patients had a history of direct contact with live poultry markets. Interestingly, poultry cage swabs and feces from the free market visited by Patient 2 one week prior to the onset of symptoms were positive for the novel avian influenza A (H7N9) virus. This indicates a direct connection between human infection with the novel H7N9 virus and an environmental source.

Researchers analyzed the DNA sequences from the Hangzhou viruses and other human H7N9 viral sequences available from the databases, together with those from other H7 influenza viruses. This showed that the virus sequenced from Patient 2 was most closely related to the virus derived from the environmental source associated with Patient 2, while Hangzhou/1 and Hangzhou/3 were more divergent. These data suggest that several H7N9 viruses are circulating in Hangzhou. It is uncertain whether the diversity of H7N9 in Hangzhou is the result of host adaptation, or predates the transmission to humans from an avian source.

The pathogenesis of the novel avian-origin H7N9 virus in humans remains unknown, although a series of substitutions that have been confirmed as pathogenicity factors in animal models were found in viruses from Hangzhou. A glutamine to isoleucine substitution was observed at position 226 of the hemagglutinin amino acid sequence in the newly sequenced virus. Isoleucine has similar characteristics to leucine, which was previously shown to be a pivotal amino acid in the binding of avian- or human-type receptor, and might be essential for pathogenicity in cases of airborne viral transmission. This substitution was observed for the first time at this site in H7N9, which may indicate a novel host adaptation feature of the H7 virus.

Findings from the current study implied a rapid evolution of the novel H7N9 virus. This may assist in determining the source and mode of transmission of these infections, and provide a reference for selecting candidate vaccine strains. The receptor binding properties of Q226I and the significance of the substitutions in H7N9 need further exploration, including both in vitro and in vivo experiments, and extensive field surveillance.

Funder: Hangzhou Key Medicine Discipline Fund for Public Health Laboratory sponsored by the Hangzhou Government, China Ministry of Science and Technology Project 973 (grant nos. 2010CB530303 and 2011CB504703), and an intramural special grant for influenza virus research from the Chinese Academy of Sciences (KSZD-EW-Z-002).

Corresponding authors:

PAN JingCao
See the article:
Li J, Yu X F, Pu X Y, et al. Environmental connections of novel avian-origin H7N9 influenza virus infection and virus adaptation to the human. Sci China Life Sci, 2013, 56(6), 485-492. doi: 10.1007/s11427-013-4491-3

Science China Press Co., Ltd. (SCP) is a scientific journal publishing company of the Chinese Academy of Sciences (CAS). For 50 years, SCP takes its mission to present to the world the best achievements by Chinese scientists on various fields of natural sciences researches.

YAN Bei | EurekAlert!
Further information:

Further reports about: Chinese herbs DNA sequence H7N9 amino acid influenza virus natural science

More articles from Health and Medicine:

nachricht Resolving the mystery of preeclampsia
21.10.2016 | Universitätsklinikum Magdeburg

nachricht New potential cancer treatment using microwaves to target deep tumors
12.10.2016 | University of Texas at Arlington

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Resolving the mystery of preeclampsia

21.10.2016 | Health and Medicine

Stanford researchers create new special-purpose computer that may someday save us billions

21.10.2016 | Information Technology

From ancient fossils to future cars

21.10.2016 | Materials Sciences

More VideoLinks >>>