Vietnam: "new" H5N1 strain detected

[Gert van der Hoek]

Deadly H5N1 strain detected

(27-08-2008)

HA NOI — A strain of the H5N1 virus that poses a high risk of infecting humans and caused an avian flu epidemic in China, has appeared in smuggled poultry in Viet Nam according to Bui Quang Anh, the head of the Ministry of Agricultural and Rural Development’s Animal Health Department yesterday.

The infection mechanism of this highly infectious strain of the H5N1 virus, named seven, had not been found so far, Anh said.

"We are studying more about this strain in our poultry and will soon know the results," said Nguyen Van Cam, the director of the Central Animal Diagnosis Centre.

The avian flu strain that has typically appeared in the Cuu Long (Mekong) Delta has been strain one, while the Song Hong (Red River) Delta has seen strain two, three and four with unknown infection mechanisms.

To prevent the strain from being spread, 242 million doses of H5N1 vaccines and 15 million of doses of H5N2 vaccines have been distributed to the localities, according to the department.

At this volume, just 76.5 per cent of poultry will be vaccinated.

Localities have typically neglected taking samples of poultry after being vaccinated. Only three out of 27 provinces that have undergone bird flu epidemics collected samples to test.

Some Cuu Long (Mekong) Delta provinces with a high volume of poultry infected with the H5N1 virus include Vinh Long at 9.25 per cent, Tra Vinh with 8.97 per cent, Soc Trang with 5.32 per cent and Long An with 5 per cent.

Anh said that more vaccines were being prepared. —

http://vietnamnews.vnagency.com.vn/showarticle.php?num=01HEA270808

 

[gsgs]

Re: Vietnam: new H5N1 strain detected

Re: Vietnam: new H5N1 strain detected

> "We are studying more about this strain in our poultry and will
> soon know the results," said Nguyen Van Cam

just upload it to genbank, and others will tell you

ahh, you want to present it to the press and scientific
community exclusively, before others do ?

No problem. But please don't let us wait 1-2 years, as typically
seen in this branch of science.

Timing could be critical.

 

[HenryN]

Re: Vietnam: new H5N1 strain detected

Re: Vietnam: new H5N1 strain detected

It is likely that the H5N1 described above is H5N1 clade 7, which caused the fatal human infection in Bejing in 2003 (A/Beijing/01/2003)

http://www.who.int/csr/disease/avian_influenza/guidelines/H5VaccineVirusUpdate20080214.pdf

 

[gsgs]

Re: Vietnam: "new" H5N1 strain detected

thanks for the link.

A/Turkey/65-596/06 is a surprising good match.

I wonder, how A/Guangxi/50/01 or A/Henan/16/04 would perform

 

[HenryN]

Re: Vietnam: "new" H5N1 strain detected

thanks for the link.

A/Turkey/65-596/06 is a surprising good match.

I wonder, how A/Guangxi/50/01 or A/Henan/16/04 would perform

A good match with what?

 

[gsgs]

Re: Vietnam: "new" H5N1 strain detected

with all the 6 tested reference ferret antisera

 

[Treyfish]

Re: Vietnam: "new" H5N1 strain detected

Vir?t H5N1 7 appearance branch in Viet Nam.
26-08-2008 21:54:21 GMT+7 According to TTXVN.
At conference nationally protect against brucellosis translating, fowl and seafood, day 26/ 8, Having a nutty flavour directorate fo veterinary medicine director is Optical You reports vir?t H5N1 Branched that 7, branched that there is vection loftiness risk for people, show yourselfed in Viet Nam.
According to research about heredity of Vir?t H5N1 Vernix caseosa translate In branch Viet Nam magnetic that in the year 2007 up to now, Nine chiefly Rickety champaign sectioning is Vir?t belong to branch 1, Hong River champaign sectioning is Vir?t 2, 3, 4. This branchs vir?t are going on to transform. .
Influenzal supervisory program on chicken is typed in without a licence at frontier town shows #PP, vir?t H5N1 Branched that 7 provoked translating In china and is capable of vection for people very-high. .
Result supervises vir?t circulation H5N1 At 20 provinces, upper borough nationwide to show, fowl herd proportional has vir?t H5N1 Make up 1, 68%. Provinces belong to highly circulative Nine proportional Rickety champaign sectioning vir?t In the duck herd. Đrisk this iều shown flare transmitting translated from the duck run copper In this sectioning still be is giant size. Meanwhile, again proportional northern sectioning vir?t is highly circulative In chicken herd. .
Also according to result supervised, not already fowl flu epidemic indicative mood infected via the bird is wild. .
According to reports directorate fo veterinary medicine, take day for 26/ 8/ 2008, day fowl influenzal juicy Bamboo Marina province all the country at present only still not already via 21./:tiphat: http://www.phapluattp.vn/news/khoa-hoc/view.aspx?news_id=225586

 

[HenryN]

Re: Vietnam: "new" H5N1 strain detected

thanks for the link.

A/Turkey/65-596/06 is a surprising good match.

I wonder, how A/Guangxi/50/01 or A/Henan/16/04 would perform

That's prep specific stickiness (its not reality based).

 

[Vibrant62]

Re: Vietnam: "new" H5N1 strain detected

It is hard to tell from the translation, but post 6 seems to indicate that there is a high degree of transmission potential in humans of this Clade 7 virus. Does anyone else concur? how would they be able to determine this without human infections?

 

[Commonground]

Re: Vietnam: "new" H5N1 strain detected

I agree with you Vibrant62....from what I can understand....

branched that there is vection loftiness risk for people,

 

[Giuseppe]

Re: Vietnam: "new" H5N1 strain detected

I agree with you Vibrant62....from what I can understand....

Because of HA, NA, PB2, NS1... If someone will show these genetic motifs (affinity with human upper respiratory tract cells, tissue tropism and prompt growth at lower temperature (PB2), NS1 (high pathogenic in humans), than we can understand better if the Vietnamese representative H5N1 of the Clade 7 (alleged) is more suitable for b-to-h transmission (or h2h).

 

[HenryN]

Re: Vietnam: "new" H5N1 strain detected

It is hard to tell from the translation, but post 6 seems to indicate that there is a high degree of transmission potential in humans of this Clade 7 virus. Does anyone else concur? how would they be able to determine this without human infections?

Post six is discussing cross reactivity with ferret antisera. It has nothing to do with human cases.

 

[HenryN]

Re: Vietnam: "new" H5N1 strain detected

Because of HA, NA, PB2, NS1... If someone will show these genetic motifs (affinity with human upper respiratory tract cells, tissue tropism and prompt growth at lower temperature (PB2), NS1 (high pathogenic in humans), than we can understand better if the Vietnamese representative H5N1 of the Clade 7 (alleged) is more suitable for b-to-h transmission (or h2h).

The only data is the isolate from Bejing/1/2003 which is a fatal human infection in 2003.
The recent poultry infections in Vietnam are likely to be quite different than the 2003 isolate.

 

[HenryN]

Re: Vietnam: "new" H5N1 strain detected

H5N1 turns up at Benin poultry market

Lisa Schnirring

Staff Writer

Aug 27, 2008 (CIDRAP News) ? Agriculture officials in Benin recently reported that two chickens at a live poultry market tested positive for the H5N1 avian influenza virus, the country's first outbreak since the virus was detected there at the end of 2007.
Authorities found the virus during routine surveillance at a market in Lokossa, the capital of Mono department, located in the southern part of the country near the coast, according to an Aug 25 report from the World Organization for Animal Health (OIE).
Testing performed at Benin's national laboratory in Parakou revealed H5 highly pathogenic avian influenza, according to the report. The surveillance activity at the Lokossa market was also a training exercise for the lab's managers and officials, the OIE report said. In December 2007, when the country confirmed its first H5N1 outbreak, the samples were tested at an Italian lab.
Animal health officials have not determined the source of the outbreak, according to the report. Authorities disinfected market stalls and have restricted the movement of poultry within the country.
Outbreaks in 2007 affected two farms, also located near Benin's southern coastal area, according to previous reports. Several countries surrounding Benin have reported poultry outbreaks over the past few years, including Nigeria, Togo, Niger, and Burkina Faso.
In other developments, agriculture officials in Vietnam said yesterday that an unusual strain of H5N1 virus is starting to appear in smuggled poultry, the state-run Vietnam News Agency (VNA) reported in a sketchy story today. Bui Quang Anh, head of the agriculture ministry's animal health department, told VNA that the strain poses a high risk of infecting humans and had previously caused an outbreak in China.
Anh told VNA that the H5N1 strain was named "seven." The story did not mention a clade number. Typically, the story said, "strain one" of the H5N1 virus has infected birds in the Mekong delta, while strains two, three, and four have been found to infect birds in the country's Red River Basin.
Nguyen Van Cam, director of Vietnam's Central Animal Diagnosis Centre, told VNA the lab was doing more tests to better characterize the strain and that he expected results soon.
See also:
Aug 25 OIE report
Dec 17, 2007, CIDRAP News story "Benin confirms its first H5N1 outbreaks"

http://www.cidrap.umn.edu/cidrap/content/influenza/avianflu/news/aug2708avian-br.html

 

[HenryN]

Re: Vietnam: "new" H5N1 strain detected

Commentary

http://www.recombinomics.com/News/08280801/H5N1_Vietnam_7.html

 

[Commonground]

Re: Vietnam: "new" H5N1 strain detected

Dr. Niman, is there any significance to "position 190"?

 

[HenryN]

Re: Vietnam: "new" H5N1 strain detected

Dr. Niman, is there any significance to "position 190"?

It is part of the receptor binding domain. It can also affect tissue tropism (where the virus can go when it gets in - may be related to the "breathing difficulties" being reported for seasonal flu in southern hemisphere, if it is H1N1, which also has changes clustered around 190.

 

[Commonground]

Re: Vietnam: "new" H5N1 strain detected

Thanks. I certainly don't like the fact that it is part of the receptor binding domain.

 

[AlaskaDenise]

Re: Vietnam: "new" H5N1 strain detected

Commentary

http://www.recombinomics.com/News/08280801/H5N1_Vietnam_7.html

Commentary

H5N1 Clade 7 Spread to Vietnam
Recombinomics Commentary 14:17
August 28, 2008

Anh told VNA that the H5N1 strain was named "seven." The story did not mention a clade number. Typically, the story said, "strain one" of the H5N1 virus has infected birds in the Mekong delta, while strains two, three, and four have been found to infect birds in the country's Red River Basin.

Nguyen Van Cam, director of Vietnam's Central Animal Diagnosis Centre, told VNA the lab was doing more tests to better characterize the strain and that he expected results soon.

The above comments from a CIDRAP update describe a new H5N1 clade in Vietnam, which is likely clade 7. The first confirmed H5N1 in mainland China was A/Beijing/01/2003 and is clade 7 isolates from a fatal case in Beijing in 2003. As seen in the WHO pandemic vaccine target phylogram. A more recent clade 7 isolate is from A/chicken/Shanxi/2/2006 which involved a significant poultry outbreak in Shanxi in 2006. This outbreak was described in multiple OIE reports, which detailed the use of three different anti-sera in efforts to bring the outbreak under control. The public sequences include multiple non-synonymous changes clustered around receptor binding domain position 190 (H3 numbering), as well as additional acquisitions, which subsequently appeared in the clade 2.2 vaccine resistant strain in Egypt and Israel.

These shared polymorphisms which were reported on genetically distinct H5N1 backgrounds illustrate the movement of polymorphisms via homologous recombination. This type of rapid change can defeat efforts using mismatched vaccines.

It is of note that the poultry vaccine effort in Egypt, like the effort in Vietnam, includes use of an H5N2 vaccine directed against a low path H5 target, which has also been used in Hong Kong. The extended use of these poorly matched vaccines has been associated with the repeated re-emergence of H5N1 in vaccinated regions, which may also be associated with an accelerated evolution to escape from the mismatched vaccine.

This type of evolution associated with mismatched vaccines is not limited to H5N1. Last season the trivalent seasonal flu vaccine was mismatched in all three targets. The mismatch in H1N1 was less obvious because the Bribane/59 isolates were being characterized as Solomon Island/3-like, even though Solomon Island/3 was no longer in widespread circulation. This season the H1N1 target is switch to Brisbane/59, but early HA sequences from South Africa already has a cluster of changes near the receptor binding domain position 190 including adjacent polymorphisms matching H1N1 sequences from the 1940’s. These rapidly evolving sequences were on the common H1N1 sequences which included Tamiflu resistance marker, H274Y, whichn is now at 100% of H1N1 isolates in South Africa and Australia.

The season and pandemic vaccine mismatches, and associated influenza evolution, remained causes of concern.


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