Featured Research

from universities, journals, and other organizations

Migratory Birds: Innocent Scapegoats For The Dispersal Of The H5N1 Virus

Date:
March 27, 2007
Source:
Blackwell Publishing Ltd.
Summary:
A review, soon to be published in Ibis, critically examines the arguments concerning the role of migratory birds in the global dispersal of the highly pathogenic avian influenza virus H5N1. The authors conclude that human commercial activities, particularly those associated with poultry, are the major factors that have determined its global dispersal.

Migratory birds, such as these gulls seen here at a resting staging post, are too readily blamed for the spread of H5N1 without any evidence to support such claims.
Credit: Steve Dudley

A review to be published shortly in the British Ornithologists' Union's journal, Ibis, critically examines the arguments concerning the role of migratory birds in the global dispersal of the highly pathogenic avian influenza virus H5N1. Ecologists of the Station Biologique de la Tour du Valat and of the GEMI-CNRS in the Camargue (France), Michel Gauthier-Clerc, Camille Lebarbenchon and Frιdιric Thomas conclude that human commercial activities, particularly those associated with poultry, are the major factors that have determined its global dispersal.

Highly pathogenic avian influenza virus subtype H5N1 was first detected in poultry in November 1996 in south-east China. The virus subsequently dispersed throughout most of Asia, and also to Africa and Europe. From mid-2005, migratory wild birds have been widely considered to be the primary source of the dispersal of H5N1 outside Asia. This claim was based on the discovery in May 2005 that hundreds of wild birds had died on Lake Quinghaihu, on the high Asian plateau in China. It is however clear that the trajectory of the virus does not correspond with to the main migration routes of wild birds. The global network of migration routes seemed to hide the globalisation - without strict health control - of the exchanges of poultry, the more likely mechanism for disease spread.

During the previous epizooties of highly pathogenic subtypes of H5 and H7, it was shown that the expansion of these viruses was due to human activities, in particular, movements of poultry or their products. This commercial scenario is the one that explained the expansion and the maintenance of the H5N1 virus in south-east Asia until 2004, via the legal and illegal trade in poultry.

The cases in western Europe in February 2006 after a cold spell on the Black Sea showed that virus can spread through infected wild birds travelling short distances, but no evidence for long distance transmission during seasonal migration has yet been found. The evidence overwhelmingly supports the hypothesis that human movements of domestic poultry have been the main agent of global dispersal of the virus to date. The occurrence of an outbreak at a commercial turkey farm in Suffolk, England, in February 2007 fits this wider pattern.

Wild birds, particularly waterfowl, are a key element of the viral ecology of low pathogenic avian influenza. Very high densities of domestic animals and increased stress factors are particularly favourable for the maintenance and transmission of virulent agents, in particular subtypes of highly pathogenic influenza. Paradoxically, the H5N1 virus coupled with a fear of transmission by wild birds could lead to a reversion to battery farming which increases risk of outbreaks. This would stall the current trend to better animal welfare resulting from free-range agriculture. Maintaining these trends, whilst controlling disease through strong veterinary scrutiny and control of trade, is more likely to be a successful strategy.


Story Source:

The above story is based on materials provided by Blackwell Publishing Ltd.. Note: Materials may be edited for content and length.


Cite This Page:

Blackwell Publishing Ltd.. "Migratory Birds: Innocent Scapegoats For The Dispersal Of The H5N1 Virus." ScienceDaily. ScienceDaily, 27 March 2007. <www.sciencedaily.com/releases/2007/03/070326121059.htm>.
Blackwell Publishing Ltd.. (2007, March 27). Migratory Birds: Innocent Scapegoats For The Dispersal Of The H5N1 Virus. ScienceDaily. Retrieved September 21, 2014 from www.sciencedaily.com/releases/2007/03/070326121059.htm
Blackwell Publishing Ltd.. "Migratory Birds: Innocent Scapegoats For The Dispersal Of The H5N1 Virus." ScienceDaily. www.sciencedaily.com/releases/2007/03/070326121059.htm (accessed September 21, 2014).

Share This



More Plants & Animals News

Sunday, September 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: San Diego Zoo Welcomes Cheetah Cubs

Raw: San Diego Zoo Welcomes Cheetah Cubs

AP (Sep. 20, 2014) — The San Diego Zoo has welcomed two Cheetah cubs to its Safari Park. The nearly three-week-old female cubs are being hand fed and are receiving around the clock care. (Sept. 20) Video provided by AP
Powered by NewsLook.com
Chocolate Museum Opens in Brussels

Chocolate Museum Opens in Brussels

AFP (Sep. 19, 2014) — Considered a "national heritage" in Belgium, chocolate now has a new museum in Brussels. In a former chocolate factory, visitors to the permanent exhibition spaces, workshops and tastings can discover derivatives of the cocoa bean. Duration: 01:00 Video provided by AFP
Powered by NewsLook.com
Could Grief Affect The Immune Systems Of Senior Citizens?

Could Grief Affect The Immune Systems Of Senior Citizens?

Newsy (Sep. 19, 2014) — The study found elderly people are much more likely to become susceptible to infection than younger adults going though a similar situation. Video provided by Newsy
Powered by NewsLook.com
Jury Delivers Verdict in Salmonella Trial

Jury Delivers Verdict in Salmonella Trial

AP (Sep. 19, 2014) — A federal jury has convicted three people in connection with an outbreak of salmonella poisoning five years ago that sickened hundreds of people and was linked to a number of deaths. (Sept. 19) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins