Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Low-pathogenic forms of bird flu do cause illness among birds: Mild form of bird flu slows down migration of swans

31.01.2007
Migratory swans carrying a mild form of avian influenza depart from The Netherlands more than a month after their healthy counterparts do. They also feed slower and fly shorter distances.

These insights will be published on January 31, 2007 in PLoS ONE, the International, peer-reviewed, open-access, online publication from the Public Library of Science (PLoS) by scientists from the Netherlands Institute of Ecology (NIOO-KNAW) and the Department of Virology of the Erasmus MC. This contrasts previous ideas that mild forms of bird flu do not cause illness among wild birds. Moreover, these patterns can affect the rate of spread of avian influenza.

Wild birds were thought not to suffer from mild forms of avian influenza. But new data suggest that so-called ‘low-pathogenic’ avian influenza viruses do affect the lives of birds. The Bewick’s swan (Cygnus columbianus bewickii) is a migratory bird that breeds in NW-Russia and overwinters in NW-Europe, especially in The Netherlands. In this species, a team of ecologists and virologists showed that infected individuals initiate their migration by the end of January or early February, while uninfected individuals already do so by the end of December. Also, their next ‘fuelling station’ is only 35 km away instead of the usual 250 km. Sick birds fuel at a lower rate: they take fewer bites per day and their digestion seems to be impaired. Presumably, this is due to their need to channel more energy towards their immune system.

Being ill is no fun for us, but for a migratory bird being ill could potentially mess up its whole calendar for the rest of the year. According to scientist Jan van Gils from NIOO, “Infected swans clearly suffer from their ‘mild’ disease. The late departure from the wintering grounds could lead to late arrival in the breeding grounds, and thus to a lost breeding season. All in all, these low-pathogenic viruses have a much greater impact than previously thought. Because of their slower migration, ill birds get in touch with many more healthy birds passing by them on migration. In this way the virus can spread itself more rapidly than previously thought.”

Acquiring more knowledge about mild but illness-causing avian influenza viruses is very important. Van Gils adds, “These mild virus-types always formed the origin of massive pandemics such as the Spanish Flu. Only such viruses that are non-lethal to birds can be spread easily by (wild or captive) birds, simply because the birds stay alive.” Only after mixing with human flu can such a low-pathogenic avian flu cause the nightmare of a deadly pandemic among humans. “High-pathogenic avian flu that causes death among birds seems to originate from intensive poultry farms.”

In the Dutch study 25 swans were investigated. The birds were caught in polder Wieringermeer (NW-Netherlands) last winter and were measured, weighed and screened for the prevalence of avian influenza viruses. Twelve birds were equipped with a GPS attached to their neck collar (80 g in total). This enabled the researchers to follow the birds’ movements in great detail. When within 300 m of the bird, all “travel data” were downloadable by wireless modern technology. Birds were found back by volunteer bird watchers reading and reporting the code on each bird’s neck collar. Among the twelve neck-collared birds, two were infected with bird flu: type H6N2 and H6N8. These mild virus types are common among free-living waterfowl. From antibodies found back in blood samples it could be concluded that a few more individuals had been infected before but were fully recovered and behaved as the other healthy birds. Both birds that were infected last winter have returned this winter and seem fully recovered too.

Froukje Rienks | alfa
Further information:
http://www.plosone.org
http://www.nioo.knaw.nl

More articles from Ecology, The Environment and Conservation:

nachricht Reducing household waste with less energy
18.01.2017 | FIZ Karlsruhe – Leibniz-Institut für Informationsinfrastruktur GmbH

nachricht Joint research project on wastewater for reuse examines pond system in Namibia
19.12.2016 | Technische Universität Darmstadt

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

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

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

Explaining how 2-D materials break at the atomic level

18.01.2017 | Materials Sciences

Data analysis optimizes cyber-physical systems in telecommunications and building automation

18.01.2017 | Information Technology

Reducing household waste with less energy

18.01.2017 | Ecology, The Environment and Conservation

VideoLinks
B2B-VideoLinks
More VideoLinks >>>