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Published Date: 2008-12-15 11:00:47
Subject: PRO/AH/EDR> Avian influenza (118): China (HK), India (AS), OIE
Archive Number: 20081215.3938

AVIAN INFLUENZA (118): CHINA (HONG KONG), INDIA (ASSAM), OIE
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In this update:
[1] China (Hong Kong): OIE immediate notification report
[2] India (Assam): OIE follow-up report

******
[1] China (Hong Kong): OIE immediate notification report
Date: Sun 14 Dec 2008
Source: OIE WAHID (World Animal Health Information Database) weekly
disease information 2008; 21(51) [edited]
<http://www.oie.int/wahis/public.php?page=single_report&pop=1&reportid=7609>

Highly pathogenic avian influenza, Hong Kong (PR China)
-------------------------------------------------------
Information received on (and dated) 12 Dec 2008 from Dr Thomas Sit,
Assistant Director, Inspection & Quarantine, Agriculture, Fisheries
and Conservation Department, Cheung Sha Wan, Hong Kong, Hong Kong (PR China)

Summary
Report type: immediate notification
Start date: 8 Dec 2008
Date of first confirmation of the event: 8 Dec 2008
Report date: 12 Dec 2008
Date submitted to OIE: 12 Dec 2008
Reason for notification: reoccurrence of a listed disease
Date of previous occurrence: October 2008
Causal agent: highly pathogenic avian influenza virus [HPAI]
Serotype: H5N1
Nature of diagnosis: suspicion, clinical, laboratory (basic),
laboratory (advanced), necropsy
This event pertains to the whole country

New outbreaks
Outbreak 1 Yuen Long, Hong Kong
Date of start of the outbreak: 8 Dec 2008
Outbreak status: continuing (or date resolved not provided)
Epidemiological unit: farm
Species: birds
Susceptible: 67 968
Cases: 285
Deaths: 285
Destroyed: 67 683
Slaughtered: 0
Affected population: there were 67 968 chickens and 25 680 fertilized
eggs on this index farm with compulsory avian influenza vaccination
program and strict biosecurity measures in place. Unusual mortality
was first noted in the sentinel chickens on 8 Dec [2008]. Clinical
signs observed included rales, dyspnoea, cyanosis, and oedema of the
comb and wattle with yellow creamy nasal discharge. Cloacae swabs and
chicken carcasses were collected on the same day for laboratory
testing. Culling of the chickens and eggs began on 9 Dec [2008] and
finished on 10 Dec [2008].

Summary of outbreaks
Total outbreaks: 1
Outbreak statistics
Species: birds
Apparent morbidity rate: 0.42 percent
Apparent mortality rate: 0.42 percent
Apparent case fatality rate: 100 percent
Proportion susceptible animals lost*: 100 percent
* Removed from the susceptible population through death, destruction,
and/or slaughter

Epidemiology
Source of the outbreak(s) or origin of infection: under investigation
Epidemiological comments: on 11 Dec 2008, 17 960 chickens were also
culled in a chicken farm within the 3-km (2 mi) radius infected zone.
Poultry in the wholesale market (10 704 chickens, 2900 pigeons, 1420
pheasants, 3100 silky chickens, and 370 chukars) were also culled on
11 Dec 2008. Initial surveillance using PCR [polymerase chain
reaction] did not detect any H5 in all the other poultry farms in
Hong Kong (virus isolation pending). Advice was given to these
unaffected chicken farms to administer a booster vaccine immediately.
Importation of live poultry was banned and movement of poultry, eggs,
fodder, and other things in local farms is prohibited for 21 days as
from 9 Dec 2008.

Control measures
Measures applied
- stamping out
- quarantine
- movement control inside the country
- screening
- zoning
- vaccination in response to the outbreak
- disinfection of infected premises/establishment(s)
- no treatment of affected animals

Measures to be applied
No other measures

Diagnostic test results
Laboratory name and type: Tai Lung Veterinary Laboratory,
Agriculture, Fisheries and Conservation Department (national laboratory)
Species: birds
Test: immunohistochemical test
Test date: 8 Dec 2008
Result: positive
Species: birds
Test: polymerase chain reaction (PCR)
Test date: 8 Dec 2008
Result: positive
Species: birds
Test: virus isolation
Test date: 11 Dec 2008
Result: positive

Future reporting
The event is continuing. Weekly follow-up reports will be submitted.

--
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ProMED-mail
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******
[2] India (Assam): OIE follow-up report
Date: Sun 14 Dec 2008
Source: OIE WAHID (World Animal Health Information Database) weekly
disease information 2008; 21(50) [edited]
<http://www.oie.int/wahis/public.php?page=single_report&pop=1&reportid=7606>

Highly pathogenic avian influenza, India
----------------------------------------
Information received on (and dated) 11 Dec 2008 from Mr Natarajan
Gokulram, Secretary to the Government of India, Department of Animal
Husbandry, Dairying and Fisheries, Ministry of Agriculture, New Delhi, India

Summary
Report type: follow-up report No. 1
Start date: 21 Nov 2008
Date of first confirmation of the event: 27 Nov 2008
Report date: 11 Dec 2008
Date submitted to OIE: 12 Dec 2008
Reason for notification: reoccurrence of a listed disease
Date of previous occurrence: November 2008
Causal agent: Highly pathogenic avian influenza virus [HPAI]
Serotype: H5N1
Nature of diagnosis: laboratory (basic), laboratory (advanced)
This event pertains to a defined zone within the country
Related reports: immediate notification (28 Nov 2008); follow-up
report No. 1 (11 Dec 2008)

New outbreaks
Outbreak 1: Patgaon, Rani, Kamrup, Assam
Date of start of the outbreak: 28 Nov 2008
Outbreak status: continuing (or date resolved not provided)
Epidemiological unit: village
Species: birds
Susceptible: 7884
Cases: 682
Deaths: 682
Destroyed: 7202
Slaughtered: --
Affected population: backyard poultry mainly in a small village.

Outbreak 2: Sarpara, Rampur, Kamrup, Assam
Date of start of the outbreak: 30 Nov 2008
Outbreak status: continuing (or date resolved not provided)
Epidemiological unit: village
Species: birds
Susceptible: 168 054
Cases: 30
Deaths: 30
Destroyed: 168 024
Slaughtered: --
Affected population: backyard poultry mainly in a small village.

Outbreak 3: Katajhar, Gobardhana, Barpeta, Assam
Date of start of the outbreak: 30 Nov 2008
Outbreak status: continuing (or date resolved not provided)
Epidemiological unit: village
Species: birds
Susceptible: 10 715
Cases: 18
Deaths: 18
Destroyed: 10 697
Slaughtered: --
Affected population: backyard poultry mainly in a small village.

Outbreak 4: Katla, Pachim Nalbari, Nalbari, Assam
Date of start of the outbreak: 30 Nov 2008
Outbreak status: continuing (or date resolved not provided)
Epidemiological unit: village
Species: birds
Susceptible: 8406
Cases: 75
Deaths: 75
Destroyed: 8331
Slaughtered: --
Affected population: backyard poultry mainly in a small village.

Outbreak 5: Khanapara, Guwahati, Kamrup, Assam
Date of start of the outbreak: 5 Dec 2008
Outbreak status: continuing (or date resolved not provided)
Epidemiological unit: farm
Species: birds
Susceptible: 1231
Cases: 112
Deaths: 112
Destroyed: --
Slaughtered: --
Affected population: a chick-rearing farm

Outbreak 6: Nilibari, Sidli Chirang, Chirang, Assam
Date of start of the outbreak: 5 Dec 2008
Outbreak status: continuing (or date resolved not provided)
Epidemiological unit: village
Species: birds
Susceptible: 1500
Cases: 399
Deaths: 399
Destroyed: --
Slaughtered: --
Affected population: backyard poultry mainly in a small village.

Outbreak 7: Jalah, Bezera, Kamrup, Assam
Date of start of the outbreak: 6 Dec 2008
Outbreak status: continuing (or date resolved not provided)
Epidemiological unit: village
Species: birds
Susceptible: 2500
Cases: 500
Deaths: 500
Destroyed: --
Slaughtered: --
Affected population: backyard poultry mainly in a small village.

Outbreak 8: Ward No. 6, East Revenue Circle, Dibrugarh, Dibrugarh, Assam
Date of start of the outbreak: 7 Dec 2008
Outbreak status: continuing (or date resolved not provided)
Epidemiological unit: village
Species: birds
Susceptible: 120
Cases: 120
Deaths: 120
Destroyed: --
Slaughtered: --
Affected population: backyard poultry mainly in a small village.

Summary of outbreaks
Total outbreaks: 8
Total animals affected
Species: birds
Susceptible: 200 410
Cases: 1936
Deaths: 1936
Destroyed: 194 254
Slaughtered: --

Outbreak statistics
Species: birds
Apparent morbidity rate: 0.97 percent
Apparent mortality rate: 0.97 percent
Apparent case fatality rate: 100 percent
Proportion Susceptible: animals lost*: **
* Removed from the susceptible population through death, destruction,
and/or slaughter
** Not calculated because of missing information

Epidemiology
Source of the outbreak(s) or origin of infection: unknown or inconclusive
Epidemiological comments: epidemiological investigation is ongoing.
Stamping out of all domestic poultry is being applied in an
approximately 3-km [2 mi] radius zone around the outbreaks followed
by compensation of the owners.
An intensive surveillance campaign has been launched in a 10-km [6
mi] radius zone including:
- closure of poultry markets and prohibition on sale and
transportation of poultry products in the infected zone;
- disinfection of premises after culling and sealing of premises
where appropriate.
Restocking will be applied in accordance with a specific protocol.

Control measures
Measures applied
- stamping out
- quarantine
- movement control inside the country
- screening
- no vaccination
- no treatment of affected animals.

Measures to be applied
- disinfection of infected premises/establishment(s)
- dipping/spraying

Diagnostic test results
Laboratory name and type: High Security Animal Disease Laboratory,
Bhopal (national laboratory)
Species: birds
Test: real-time PCR [polymerase chain reaction]
Test date: 1 Dec 2008
Result: positive
Species: birds
Test: real-time PCR
Test date: 3 Dec 2008
Result: positive
Species: birds
Test: real-time PCR
Test date: 9 Dec 2008
Result: positive
Species: birds
Test: reverse transcription - polymerase chain reaction (RT-PCR)
Test date: 1 Dec 2008
Result: positive
Species: birds
Test reverse transcription - polymerase chain reaction (RT-PCR)
Test date: 3 Dec 2008
Result: positive
Species: birds
Test: reverse transcription - polymerase chain reaction (RT-PCR)
Test date: 9 Dec 2008
Result: positive

Future reporting
The event is continuing. Weekly follow-up reports will be submitted.

--
Communicated by:
ProMED-mail
<promed@promedmail.org>

[There have now been a total of 9 farm outbreaks associated with this
incident. H5N1 outbreaks in India started in January 2006 with 2
farms, 3 in March, and 2 in April 2006. This cluster was widely
dispersed and centered mostly in the western state of Maharashtra but
included 2 farms in Gujarat and 1 in Madhya Pradesh. In July 2007
there was an outbreak in Manpur, which borders Assam province.

In January this year (2008), there were 33 outbreaks, 4 occurred in
March, 3 in April, and 2 in May. The majority of these outbreaks were
located in West Bengal, although 3 occurred in the state of Tripura,
near Assam and Manipur.

Bangladesh, which is in between the outbreak areas of West Bengal and
Assam state of India has had massive outbreaks in 2007, totaling 287
farms. Obviously, there is concern now that more outbreaks in Assam
state will follow and ProMED-mail will keep you updated.

The 2 outbreak situations though do represent very different control
strategies, which follow from the different epidemiologic situations
as well as the previous experience the country has had with H5N1.

Hong Kong, if you recall was the 1st place in the world in 1997 where
the H5N1 virus emerged, although there is some thought that it had
existed in Guangzhou province for some time. The animal and public
health officials there eventually took the dramatic but highly
successful disease control measure of culling and shutting down the
markets, cleaning and disinfecting, while instituting the long term
measures detailed in the report above including biosecurity,
vaccination, and various surveillance strategies. Furthermore,
depopulation of the infected farm was carried out in less than 48
hours from the time clinical signs were noted. So it is not
surprising that the combination of aggressive disease control
tactics, a geographically circumscribed and limited number of
production premises, and a populace which has become highly aware of
and educated about the devastation occasioned by the incursion of the
H5N1 virus and how best to control it, would lead me to predict a
likelihood of success when it comes to controlling the disease in
Hong Kong. A sort of one and done situation is likely.

The situation in India projects a different picture though. There
have been hundreds of premises infected by H5N1 in nearby Bangladesh
and 42 farms affected last year (2007) in the nearby states of West
Bengal, Manipur, and Tripura. Seven of the 8 outbreaks occurred in
bird population whose epidemiologic unit was a village. The other one
was a chick-rearing farm. While it is good that there is
compensation, which is a critical element for success, this is also
apparently not a population that lends itself to vaccination at this
time (which can be helpful under the right circumstances). This
control program really relies on stamping out so it is a little bit
troublesome that the numbers in the OIE report presented here don't
quite add up. Case fatality rates on all the farms are 100 percent,
which indicates a virulent virus but mortality rates vary from less
than 10 percent to 100 percent. On 3 of the farms (Khanapara,
Nilibari, and Jalah), there appear to be 4220 exposed birds that did
not fall into the categories of die, destroyed, or slaughtered and
appear to be unaccounted for. On the chick-rearing farm, there were
1121 birds, which appear to be exposed but did not fall into the
categories of death, destroyed, or slaughtered. I suspect there are
good reasons for this apparent discrepancy and ProMED-mail would
definitely like to have more information on the course of the
outbreak. In any case, for all the reasons above, it not clear what
the future direction of the outbreak is likely to be. But one has to
be cautious and hope that the biosecurity education is increased
markedly and very effective stamping out procedures are put in place
quickly. - Mod.PC

[The location of the outbreaks can be seen on the maps at the source
URLs. - CopyEd.MJ]

See Also