Published Date: 2002-04-18 23:50:00
Subject: PRO/AH> Avian influenza - China (Hong Kong) (09)
Archive Number: 20020418.3979
AVIAN INFLUENZA - CHINA (HONG KONG) (09)
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See Also
Avian influenza - China (Hong Kong) (02) 20020206.3492Avian influenza - China (Hong Kong) (08) 20020405.3890
Avian influenza, transmission to humans: genetics 20020106.3179
[1
Date: Wed, 17 Apr 2002
From: Pablo Nart <p.nart@virgin.net>
Source: Hoover 17 Apr 2002
<http://hoovnews.hoovers.com/fp.asp?layout=displaynews&doc_id=N
R200 20417670.2_b02c0011a5047066>
Avian Influenza (Hong Kong) Virus typing
-----------------------------------------
Genetic tests on the latest bird flu virus have revealed that it is based on
the strain that caused last year's outbreak -- proving that measures to
eradicate the disease have failed, according to the scientist who
conducted the study.
Gene sequencing expert Dr Guan Yi, who has been working on Hong
Kong's bird flu problem since the original 1997 outbreak, said that
ending the live chicken trade could be the only way to halt the disease
once and for all. All SAR chicken farms should be shut down and the
importation of live chickens from the mainland banned, said Dr Guan,
assistant research professor at the University of Hong Kong's
department of microbiology.
Dr Guan said of the latest strain: "In one day it could kill 10 000 stock
if the farm is isolated and has not been [previously exposed to an
H5N1 virus." He added: "I believe we have to get rid of the farms, and
the poultry markets, and the import of fresh chickens."
His call for the closure of Hong Kong's chicken farms is likely to meet
strong opposition from the poultry industry, on which the livelihoods
of tens of thousands of people depend and which generates about $23
million a month in revenue.
One international organisation representing the poultry industry said
last night that shutting down farms in response to the outbreaks would
be an "ignorant act".
Dr Guan gene-sequenced both the 2001 and 2002 H5N1 viruses, and
was part of the team recruited by the World Health Organisation and
the US Centers for Disease Control and Prevention to investigate the
1997 bird flu outbreak that jumped the species barrier and killed 6
people.
The 2001 outbreak originated in markets, rather than farms, and the
gene sequencing results meant the same was probably true of this year's
outbreak, Dr Guan said. Last year's virus, which was first detected at
Yueng Uk market in early April, led to the slaughter of 1.2 million
chickens. It was never detected in farms.
However, this year's outbreak, which began in February 2002, was
centred on farms in the Yuen Long district. It has led to the first
chicken vaccination programme at Pak Sha farms and the slaughter of
about 950 000 birds.
A market rest day has been imposed on the 25th of every month since
June 2001 to cleanse markets and stop the virus mutating into new
forms. However, Dr Guan said: "Although the rest day is useful, I do
not think it is enough to control the virus. One month [between rest
days is too long."
The mutations which produced the current strain had made it lethal in
laboratory chickens in less than 20 hours, he said. The tests were
conducted by St Jude Children's Research Hospital in Memphis,
Tennessee, which is used by the World Health Organisation to study
animal influenza.
In 1997, the H5N1 virus comprised only one so-called genotype, or
gene family, and was based on the Guangdong goose virus that
infected mainland chickens months before the Hong Kong outbreak. In
2001, the H5N1 virus comprised 5 genotypes, indicating that it had
undergone substantial mutation, Dr Guan said. By this year, the virus
had again increased in complexity to comprise 6 or 7 genotypes which
were "based on last year's virus", he said. It was not possible to say
what made a bird flu virus potentially harmful to humans, he said.
Peter Wong Chun-kow, Hong Kong president of the World Poultry
Science Association, said: "Avian influenza is just like any human flu --
you just cannot get rid of it. However, it does not make sense to get rid
of the poultry industry to get rid of the bird flu. This would be an
ignorant act."
Legislator Dr Lo Wing-lok, an infectious disease specialist, said there
would always be room for small but well-managed farms. "[Even if
chilled chicken dominates in the future, there will still be a demand for
locally bred and designer-type chickens, [albeit a very small market,"
he said. There are about 140 chicken farms in Hong Kong, down from
a high of 4000 in the 1970s.
******
[2
Date: Wed, 17 Apr 2002
From: ProMED-mail <promed@promedmail.org>
Source: China Daily - Hong Kong edition, 12 Apr 2002 [edited
<http://www1.chinadaily.com.cn/hk/2002-04-12/65343.html>
Vaccination to control bird flu
-----------------------------------
Hong Kong health authorities launched a vaccination programme at 21
chicken farms yesterday in a bid to control the spread of the potentially
deadly bird flu, a government spokeswoman said.
"We have started the vaccination programme at one farm covering
about 11 000 chickens," a spokeswoman for the agriculture, fisheries
and conservation department (AFCD) said. The farm is one of 21 in
the Pak Sha area in the northern New Territories that will be targeted
by the programme. About 400 000 remaining live chickens in Pak Sha
and any new consignment of chickens moving to the area will also be
vaccinated. The programme, which will last about 10 days, is part of an
effort to protect chickens against the disease and help control the
spread of the virus, she added.
Health officials slaughtered more than 30 000 chickens at 2 farms last
Saturday and introduced the vaccination programme amid another
outbreak of deadly bird flu. The latest cull followed an earlier slaughter
of chickens at 2 other farms in Pak Sha after the discovery of dead
birds and the detection of the H5 bird flu virus.
In February 2002, some 7000 chickens were culled at a farm in the
same area after birds were found to have died of the H5 flu virus. The
virus was related to the H5N1 strain which crossed the species barrier
and killed 6 people in Hong Kong in 1997.
A total of 860 000 chickens were killed to curb the February 2002
outbreak. About 8 months previously, 1.2 million birds were culled --
at a cost to the government of 31.45 million U.S. dollars in
compensation -- also to stamp out bird flu.
--
ProMED-mail
<promed@promedmail.org>
[We observe a continued trend of modernization in the poultry industry
of Hong Kong. This is manifested by the significant reduction in the
number of holdings while increasing their size. The authorities seem to
be enhancing disease surveillance activities and investing in efforts to
improve the sanitation on the farms and markets. These steps,
combined with an intensive vaccination regime, might enable the
continuation of the local poultry industry and, hopefully, will avoid the
necessity to apply extreme measures, such as "getting rid of the farms".
Mod.AS
...............................as/pg/jw
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