Advisory Council on Food and Environmental Hygiene
outbreaks in South Korea, Vietnam and Japan
paper briefs Members of the current H5 avian influenza outbreaks
in South Korea, Vietnam and Japan and the measures implemented in
Hong Kong to prevent occurrence of similar outbreaks.
influenza outbreak in South Korea
Ministry of Agriculture and Forestry (MAF) of the Republic of Korea
(South Korea) reported to the Office International des Epizooties
(OIE) on 12 December 2003 that an H5 highly pathogenic avian
influenza (HPAI) outbreak occurred in a chicken farm in Chungcheong-buk-do
province, about 80 km south east of Seoul. According to epidemiological
investigation, the avian flu virus might have come from migratory
birds. Many migratory birds inhabited in ponds near the index farm.
strategy being used by South Korea to control the outbreak includes
(i) a stamping out policy of infected farms; (ii) quarantine measures
on suspected farms; and (iii) movement restrictions within 10 km
radius of affected farm. Vaccination is not adopted.
According to the information available to us, infection had been
confirmed at 16 farms by mid January 2004, and about 16 farms were
under investigation. In one case, the disease was also found
in a quail farm. According to media reports, by end December
2003, more than 1.2 million birds had been killed to contain the
disease and the MFA was planning to destroy 2.5 million chickens
and 150,000 ducks to stop the outbreak.
human cases have been reported so far in connection with the South
do not import any live poultry and birds from South Korea. In
the first ten months of 2003, Hong Kong imported about 540 tonnes
of such products from South Korea, accounting for less than 1% of
the total volume of poultry meat imported to Hong Kong.
outbreak in Vietnam
of Animal Health of the Ministry of Agriculture and Rural Development
of Vietnam reported to the OIE on 8 January 2004 that
an H5 HPAI outbreak occurred
in three chicken farms in the Long An
Province and the Tien Giang Province, both in the Southern part
of the country. The estimated date of first infection was
reported to be 27 December 2003. It was reported that 40,000
birds had died and 30,000 birds had been destroyed.
The strategy being used by Vietnam to control the outbreak
includes (i) control of wildlife reservoirs of avian influenza viruses;
(ii) quarantine restrictions; (iii) movement control of poultry
from the affected provinces; (iv) destruction and disposal of dead
and affected birds; and (v) screening of poultry.
On 13 January 2004, the World Health
Organization (WHO) announced that it had received laboratory confirmation
of three cases of H5N1 avian influenza in humans in the Hanoi region
of Vietnam. The samples came from two children and one adult
who have since died. Since October 2003, a total of 14 cases
of severe respiratory disease have been identified in Hanoi and
surrounding provinces. Thirteen of these cases are in children and
one in an adult. To date, 11 of these children and the adult
have died. However, there is so far no evidence that all these
cases are caused by avian influenza. Some
of the cases have involved family members, but investigators are
exploring the possibility that those who fell ill may have been
exposed to a common source in poultry. Four of the five families
that have so far been interviewed reportedly recalled chickens dying
in their villages. According to the WHO, the evidence to date
suggests that there is no sign of human-to-human transmission.
We did not import any live poultry and poultry meat from
Vietnam in the past four years.
outbreak in Japan
of Agriculture, Forestry and Fisheries of Japan reported to the
OIE on 12 January 2004 that an H5 HPAI outbreak occurred in
one layer flock in a farm in Yamaguchi Prefecture. It was
reported that about 6,000 chickens were found dead on the farm and
another 30,000 chickens on the farm were killed.
The strategy being used by Japan to control the outbreak
includes (i) a stamping out policy of the affected farm; (ii) movement
control of poultry within the country; and (iii) screening of poultry.
In the first ten months of 2003, about 3,000 tonnes of poultry
meat were imported from Japan accounting for less than 1% of the
total volume of poultry meat imported to Hong Kong. The only
imports of live birds from Japan in the past 12 months were two
birds imported to a zoo in December. Both birds have completed
their post arrival quarantine and are healthy.
No human cases have been reported so far in connection with
the Japanese outbreak.
Measures implemented in Hong Kong
has approached the relevant authorities in South Korea, Vietnam
and Japan to obtain more information on the situation in these countries.
As a precautionary measure, we have temporarily suspended the importation
of live birds and poultry meat from these places. We will
continue to closely monitor the situation of the outbreaks in these
In the light of the H5 avian influenza outbreaks in South
Korea, Vietnam and Japan, we have stepped up our monitoring and
surveillance efforts to minimize the risk of recurrence of avian
influenza outbreaks in Hong Kong. A meeting chaired by the
Secretary for Health, Welfare and Food was held with the Director
of Agriculture, Fisheries and Conservation and the Director of Food
and Environmental Hygiene on 12 January 2004 to map out a strategy
for preventing avian influenza outbreaks in Hong Kong.
At the farm level, biosecurity
measures have been imposed to prevent the introduction of avian
influenza viruses to farms. In particular, to prevent infection
from wild birds, bird proofing has been implemented on all local
farms. A territory-wide H5 vaccination programme has also
been implemented since June 2003 in all local chicken farms as a
supplementary measure to prevent the recurrence of an outbreak.
The Agriculture, Fisheries and Conservation Department (AFCD) will
step up inspection of all local farms to monitor if any abnormal
circumstances occur and if all biosecurity requirements are strictly
To ensure similar levels of protection to both imported Mainland
chickens and locally produced chickens, we have also reached agreement
with the Mainland authorities on the vaccination of chickens for
export to Hong Kong. By 15 January 2004, all live chickens
available in the local market has been vaccinated. The Food
and Environmental Hygiene Department (FEHD) will conduct testing
on the imported chickens to ensure that the immunity status of imported
chickens is at a satisfactory level.
The wholesale and retail markets are also thoroughly cleansed
on a regular basis to maintain good hygiene standards. All
transport cages and vehicles are required to be cleansed and disinfected
before being used for transporting chickens. Since March 2003,
the Government has implemented two rest days per month at retail
outlets to reduce the viral load there, if any. Poultry stall
operators have to surrender all live poultry for disposal on detection
of even one dead bird with H5 virus isolated. AFCD and FEHD
will step up monitoring of the wholesale market and retail outlets
respectively to ensure that no abnormal circumstances occur.
The Government has put in place a comprehensive and sensitive
avian influenza surveillance programme covering local chicken farms,
imported chickens, the wholesale market and retail outlets.
To detect the presence of any avian influenza viruses in the environment
and the possible re-assortment of the viruses, the surveillance
programme has been extended to cover wild birds, waterfowl in recreational
parks and pet birds in the market. This enables the Government
to take responsive measures at an early stage to prevent the recurrence
of outbreaks. In 2003, a total of 17,409 samples were tested,
among which 887 were samples from wild birds and recreational parks.
The last time that H5 virus was isolated was November 2003.
Hong Kong has an intensive surveillance system for human
influenza. At this time, human influenza activity in Hong
Kong remains within historical limits and no H5N1 isolate has been
detected. The Department of Health will continue to closely
monitor the human influenza activity.
To maintain an effective strategy to address the avian influenza
problem, we will review our control measures regularly to ensure
that they have not outlived their usefulness and explore new options
to resolve the problem in light of the changing circumstances.
In particular, we will remain vigilant in keeping our guard against
any mutation or re-assortment of the virus that may have an impact
on human health.
Health, Welfare and
and Conservation Department
Food and Environmental
Department of Health