Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Novel avian influenza A virus has potential for both virulence and transmissibility in humans

10.09.2013
Virus attaches to both upper and lower respiratory tract epithelium, according to report in The American Journal of Pathology

A new study has found that a novel avian-origin H7N9 influenza A virus, which has recently emerged in humans, attaches moderately or abundantly to the epithelium of both the upper and lower respiratory tracts.

This pattern has not been observed before for avian influenza A viruses. The report, published in the October issue of The American Journal of Pathology, suggests that the emerging H7N9 virus has the potential to cause a pandemic, since it may transmit efficiently in humans and cause severe pneumonia.

The first report of infections of humans with the influenza A virus of the subtype H7N9 surfaced in March 2013. Three patients from eastern China developed severe pneumonia and acute respiratory distress syndrome and died as a result. By May 30, 2013, the H7N9 infection was confirmed in 132 patients from China and Taiwan, 37 of whom died, according to the World Health Organization. Infected poultry were thought to be the source of the virus.

In the current study, investigators focused on the virus' pattern of attachment in order to assess its potential transmissibility and virulence. "Abundant virus attachment to the human upper respiratory tract correlates with efficient transmissibility among humans," explains Thijs Kuiken, DVM, PhD, of the Department of Viroscience at Erasmus University Medical Centre in Rotterdam, The Netherlands. "Virus attachment to Clara cells in the bronchioles and pneumocytes and macrophages in the alveoli correlates with high virulence."

Using virus histochemical analysis, the investigators looked at the pattern of attachment of two genetically engineered emerging H7 viruses (containing the hemagglutinin (HA) of either influenza virus A/Shanghai/1/13 or A/Anhui/1/13) to fixed human respiratory tract tissues and compared the findings to attachment patterns seen with human influenza viruses with high transmissibility but low virulence (seasonal H3N2 and pandemic H1N1) and highly pathogenic avian influenza (HPAI) viruses with low transmissibility and high virulence (H5N1 and H7N7).

They found that like other avian influenza viruses, the H7N9 viruses attached more strongly to lower parts of the human respiratory tract than to upper parts. However, compared to other avian influenza viruses, the attachment to epithelial cells by H7N9 in the bronchioles and alveoli of the lung was more abundant and the viruses attached to a broader range of cell types. "These characteristics fit with increased virulence of these emerging avian H7 viruses compared to that of human influenza viruses," says Dr. Kuiken.

A third notable finding was a more concentrated attachment of H7N9 viruses in ciliated cells of the nasal concha, trachea, and bronchi, suggesting the potential for efficient transmission among humans. "However, the fact that the emerging H7N9 virus has caused infection mainly in individual human cases suggests that it has not acquired all the necessary properties for efficient transmission among humans," notes Dr. Kuiken.

"Our results indicate that based just on the pattern of virus attachment the H7N9 currently emerging in China has the potential both to cause severe pulmonary disease and to be efficiently transmitted among humans," says Dr. Kuiken. He emphasizes that attachment is only the first step in the replication cycle of influenza virus in its host cell, and that other steps, as well as the host response, need to be taken into account to fully understand the potential of these emerging H7 viruses to cause an influenza pandemic.

Eileen Leahy | EurekAlert!
Further information:
http://www.elsevier.com

More articles from Studies and Analyses:

nachricht Drone vs. truck deliveries: Which create less carbon pollution?
31.05.2017 | University of Washington

nachricht New study: How does Europe become a leading player for software and IT services?
03.04.2017 | Fraunhofer-Institut für System- und Innovationsforschung (ISI)

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

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

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Quantum thermometer or optical refrigerator?

23.06.2017 | Physics and Astronomy

A 100-year-old physics problem has been solved at EPFL

23.06.2017 | Physics and Astronomy

Equipping form with function

23.06.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>