Johnny Reb
Senior Member
1]
Date: Thu, 14 Jul 2005
From: ProMED-mail <promed@promedmail.org>
Source: Scienceexpress - Brevia, 6 Jul 2005, page 1/ [edited]
<http://www.sciencemag.org/cgi/rapidpdf/1115273v1.pdf>
The following paper, dated 25 May 2005, was accepted by Science
magazine 29 Jun 2005, published online 6 Jul 2005 at the URL above.
Due to its significance, we present its main parts in this posting; the
abstract, references and graphics can be seen in the original paper. For
authors' names, see commentary.
Highly Pathogenic H5N1 Influenza Virus Infection in Migratory Birds
-------------------------------------------------------------------
On 4 May 2005, a few birds were found dead on "Bird Island" and by
the end of June more than a thousand birds were affected. This lake
is one of the most important breeding locations for migratory birds
that overwinter in Southeast Asia, Tibet and India. Several species
were infected, including the bar-headed goose (_Anser indicus_),
great black-headed gull (_Larus ichthyaetus_) and brownheaded gull
(_Larus brunnicephalus_). 2 key symptoms were noticed: abnormal
neurological signs (tremor and opisthotonus) and diarrhea. Among the
gross lesions, pancreatic necrosis was obvious and was confirmed by
tissue section where extensive areas of lytic necrosis were seen,
consistent with pathology observed in domestic geese and ducks
infected with H5N1 AIV. Brain sections revealed glial cell
infiltration, perivascular cuffing, and congestion in the blood
vessels. Serological tests from one bar-headed goose and one
brown-headed gull confirmed the presence of high-titer antibody
against H5N1 AIV.
Several H5N1 viruses were isolated from the viscera, brain and the
swabs of the oropharynx and cloaca of sick and dead birds. 4 of the
isolates from different bird species were completely sequenced and
appeared to be closely related. None of the GenBank sequence data for
known H5N1 AIV genomes completely matched our sequences, implying the
viruses are reassortants. 5 of the 8 genomic segments (M, PA, PB1,
PB2 and NS) were closely related to a Hong Kong 2004 isolate
(A/peregrine falcon/HK/D0028/04).
We observed several characteristics in our 4 isolates: first, the
sequence, PQGERRRKKR/G, denoting multiple basic amino acids at the
cleavage site of the haemagglutinin (HA); 2nd, a virulence island in
the PB2 gene, E627K, first seen in Hong Kong in 1997 (5); and 3rd, a
deletion of 20 amino acids in NA (amino acid position 49-69), also
associated with high virulence.
To test virulence, mice and chickens were infected with the
BhGoose/QH/1/05 isolate. All 8 infected chickens died within 20 hours
and 7 of 8 infected mice died within 72 hours, and the last died 96
hours post-infection. Earlier isolates taken from ducks in China were
less virulent in mice and chickens. Hence we speculate that viruses
might be emerging from reassortants originating in birds
overwintering in Southeast Asia.
The occurrence of highly pathogenic H5N1 AIV infection in migrant
waterfowl indicates that this virus has the potential to be a global
threat: Lake Qinghaihu is a breeding center for migrant birds that
congregate from Southeast Asia, Siberia, Australia and New Zealand.
--
ProMED-mail
<promed@promedmail.org>
******
[2]
Date: Thu, 14 Jul 2005
From: ProMED-mail <promed@promedmail.org>
Source: Agence France Presse via Channelnewsasia, 13 Jul 2005 [edited]
<http://www.channelnewsasia.com/stories/health/view/157741/1/.html>
Scientists say China's migratory birds carry a more deadly avian flu strain
---------------------------------------------------------------------------
Wild birds in northwest China carry a more deadly strain of the H5N1
bird flu virus and pose a global threat as they begin their summer
migrations, state media has quoted scientists as saying.
The story says that so far, some 6000 birds in Qinghai province's
"bird island" -- a sanctuary with some 100 000 migratory birds --
have died from an outbreak of avian influenza discovered in May 2005.
The Wenhuibao newspaper was cited as saying that Chinese scientists
who recently tested the virus samples and completed gene sequencing
said the strain in the outbreak appeared different and more
pathogenic than strains in previous outbreaks, killing chicken within
20 hours and mice within 3 days during laboratory experiments.
Gao Fu, director of the Chinese Academy of Science's microbiology
research institute, was quoted as saying, "The results show that this
new strain of H5N1 is very harmful. The deadliness of the virus far
exceeds that of the virus strains previously found in water fowl in
northern China."
The article cited a recent report by Chinese scientists in Science
magazine.[see above].
Date: Thu, 14 Jul 2005
From: ProMED-mail <promed@promedmail.org>
Source: Scienceexpress - Brevia, 6 Jul 2005, page 1/ [edited]
<http://www.sciencemag.org/cgi/rapidpdf/1115273v1.pdf>
The following paper, dated 25 May 2005, was accepted by Science
magazine 29 Jun 2005, published online 6 Jul 2005 at the URL above.
Due to its significance, we present its main parts in this posting; the
abstract, references and graphics can be seen in the original paper. For
authors' names, see commentary.
Highly Pathogenic H5N1 Influenza Virus Infection in Migratory Birds
-------------------------------------------------------------------
On 4 May 2005, a few birds were found dead on "Bird Island" and by
the end of June more than a thousand birds were affected. This lake
is one of the most important breeding locations for migratory birds
that overwinter in Southeast Asia, Tibet and India. Several species
were infected, including the bar-headed goose (_Anser indicus_),
great black-headed gull (_Larus ichthyaetus_) and brownheaded gull
(_Larus brunnicephalus_). 2 key symptoms were noticed: abnormal
neurological signs (tremor and opisthotonus) and diarrhea. Among the
gross lesions, pancreatic necrosis was obvious and was confirmed by
tissue section where extensive areas of lytic necrosis were seen,
consistent with pathology observed in domestic geese and ducks
infected with H5N1 AIV. Brain sections revealed glial cell
infiltration, perivascular cuffing, and congestion in the blood
vessels. Serological tests from one bar-headed goose and one
brown-headed gull confirmed the presence of high-titer antibody
against H5N1 AIV.
Several H5N1 viruses were isolated from the viscera, brain and the
swabs of the oropharynx and cloaca of sick and dead birds. 4 of the
isolates from different bird species were completely sequenced and
appeared to be closely related. None of the GenBank sequence data for
known H5N1 AIV genomes completely matched our sequences, implying the
viruses are reassortants. 5 of the 8 genomic segments (M, PA, PB1,
PB2 and NS) were closely related to a Hong Kong 2004 isolate
(A/peregrine falcon/HK/D0028/04).
We observed several characteristics in our 4 isolates: first, the
sequence, PQGERRRKKR/G, denoting multiple basic amino acids at the
cleavage site of the haemagglutinin (HA); 2nd, a virulence island in
the PB2 gene, E627K, first seen in Hong Kong in 1997 (5); and 3rd, a
deletion of 20 amino acids in NA (amino acid position 49-69), also
associated with high virulence.
To test virulence, mice and chickens were infected with the
BhGoose/QH/1/05 isolate. All 8 infected chickens died within 20 hours
and 7 of 8 infected mice died within 72 hours, and the last died 96
hours post-infection. Earlier isolates taken from ducks in China were
less virulent in mice and chickens. Hence we speculate that viruses
might be emerging from reassortants originating in birds
overwintering in Southeast Asia.
The occurrence of highly pathogenic H5N1 AIV infection in migrant
waterfowl indicates that this virus has the potential to be a global
threat: Lake Qinghaihu is a breeding center for migrant birds that
congregate from Southeast Asia, Siberia, Australia and New Zealand.
--
ProMED-mail
<promed@promedmail.org>
******
[2]
Date: Thu, 14 Jul 2005
From: ProMED-mail <promed@promedmail.org>
Source: Agence France Presse via Channelnewsasia, 13 Jul 2005 [edited]
<http://www.channelnewsasia.com/stories/health/view/157741/1/.html>
Scientists say China's migratory birds carry a more deadly avian flu strain
---------------------------------------------------------------------------
Wild birds in northwest China carry a more deadly strain of the H5N1
bird flu virus and pose a global threat as they begin their summer
migrations, state media has quoted scientists as saying.
The story says that so far, some 6000 birds in Qinghai province's
"bird island" -- a sanctuary with some 100 000 migratory birds --
have died from an outbreak of avian influenza discovered in May 2005.
The Wenhuibao newspaper was cited as saying that Chinese scientists
who recently tested the virus samples and completed gene sequencing
said the strain in the outbreak appeared different and more
pathogenic than strains in previous outbreaks, killing chicken within
20 hours and mice within 3 days during laboratory experiments.
Gao Fu, director of the Chinese Academy of Science's microbiology
research institute, was quoted as saying, "The results show that this
new strain of H5N1 is very harmful. The deadliness of the virus far
exceeds that of the virus strains previously found in water fowl in
northern China."
The article cited a recent report by Chinese scientists in Science
magazine.[see above].