Joseph P. Dudley, Ph.D.
Chief Scientist, Biosecurity and Biosurveillance
EAI Corporation
4301 North Fairfax Drive, Suite 200
<jdudley@eai.com>
<dudleyjp@saic.com>
[A similar article appears
at: <http://news3.xinhuanet.com/english/2006-11/02/content_5283058.htm>]
******
[2]
Date: Thu, 2 Nov 2006 22:34:11 -0000
From: Mary Marshall <tropical.forestry@btinternet.com>
Source: Reuters [edited]
<http://www.alertnet.org/thenews/newsdesk/N02387076.htm>
Migrating ducks, geese, and swans spread the H5N1 bird flu virus from
Russia to Romania, Turkey and Ukraine, researchers said on Thursday.
A careful analysis of the spread of the virus from central Asia into
eastern Europe in the autumn of 2005 shows that wild birds,
especially mallard ducks, were the chief spreaders of the virus. "We
conclude that the spread of (highly pathogenic avian influenza) H5N1
virus from Russia and Kazakhstan to the Black Sea basin is consistent
in space and time with the hypothesis that birds in the Anatidae
family have seeded the virus along their autumn migration routes,"
the researchers wrote in the journal Emerging Infectious Diseases.
Anatidae include geese, ducks and swans, some of which are killed by
H5N1, and other species of which often show no ill effects from the
virus but which can spread it. Mallard ducks are the main suspect.
(../..)
Marius Gilbert of the Free University of Brussels and colleagues used
satellite data to figure out the start of the autumn migration, and
plotted known seasonal migration pathways against the actual
outbreaks of H5N1. They noted that adult birds can transmit the
virus easily to juveniles during the molting season, when they cannot
fly, and also noted that the virus can survive in cold standing water
-- where many species of birds congregate while molting. "The initial
outbreaks of (highly pathogenic) H5N1 virus in Romania, Turkey, and
Ukraine occurred close to wetlands frequented by overwintering
migratory waterfowl," they wrote.
"These locations were clearly far from any known location where ...
H5N1 virus had been recorded, while the timing and location match the
autumn wildfowl migration ahead of the approaching wave of frost."
The researchers said that their study "by no means excludes the role
of the poultry trade as an important, complementary transmission pathway."
Bird experts around the world are testing many different species to
see which ones carry and transmit the virus. U.S. and Canadian
officials say they expect highly pathogenic strains of H5N1 to
eventually arrive in the Americas, saying it is only a matter of time.
--
ProMED-mail
<promed@promedmail.org>
[Obviously the relative importance of the various epidemiologic
factors affecting spread and persistence of HPAI depend on which part
of the elephant one is examining and the tools used. On an economic
basis improper poultry raising and sales techniques are the most
important factors, outweighing all others, and patently where control
must be directed and is most cost-effective. Migrating birds play a
part in the long-distance spread of the virus(es), which is also
shared with the international movements, legal and illegal, of live
and dead poultry. - Mod.MHJ]
[see also:
Avian influenza, poultry vs migratory birds (34) 20060823.2383
Avian influenza, poultry vs migratory birds (33) 20060730.2109
Avian influenza, poultry vs migratory birds (32) 20060714.1943
Avian influenza, poultry vs migratory birds (31) 20060713.1926
Avian influenza, poultry vs migratory birds (30) 20060621.1711
Avian influenza, poultry vs migratory birds (29) 20060619.1695
Avian influenza, poultry vs migratory birds (2
20060615.1659
Avian influenza, poultry vs migratory birds (27) 20060607.1585
Avian Influenza, poultry vs migratory birds (26) 20060606.1574
Avian influenza, poultry vs migratory birds (25) 20060606.1571
Avian influenza, poultry vs migratory birds (24) 20060605.1567
Avian influenza, poultry vs migratory birds (23) 20060602.1541
Avian influenza, poultry vs migratory birds (22) 20060531.1522
Avian influenza, poultry vs migratory birds (21) 20060522.1446
Avian influenza, poultry vs migratory birds (20) 20060518.1396
Avian influenza, poultry vs migratory birds (19) 20060512.1350
Avian influenza, poultry vs. migratory birds (1
20060504.1289
Avian influenza, poultry vs migratory birds (17) 20060502.1273
Avian influenza, poultry vs migratory birds (16) 20060501.1264
Avian influenza, poultry vs migratory birds (15) 20060429.1240]
.............................................mpp/mhj/pg/mpp