Department of Livestock Development
Ministry of Agriculture of Cooperatives, Thailand
Highly pathogenic avian influenza (HPAI) is a “List A” disease according
to the OIE. Because of its highly pathogenic nature and destructive impact
on poultry production and trade, the overall policy is eradication of the
disease in the shortest period as possible to minimize all potential damages.
HPAI is enlisted by the Ministry of Agriculture and Cooperatives as a highly
contagious disease under the Animal Epidemic Act B.E.2499 (AC 1956) and
its reversion in B.E. 2542 (AC1999), which allows strategic actions of stamping-out,
movement control, quarantine, compensation, and other necessary measures
January,2004 is the first time that highly pathogenic avian influenza outbreak
occurred in Thailand. HPAI was detected in a layer farm, Bangplama district,
Suphanburi province, central region of Thailand. The emergency plan for
highly contagious avian diseases was launched immediately, all necessary
measures and operations have been implemented. Details of the operations,
which emphasize on stamping-out strategy, are summarized as follow.
1. Pre-emptive culling: Depopulation of chicken in farms
and backyard chickens in the area within 5-kilometer radius from the infected
farm, followed by disinfecting of the premises.
2. Surveillance during the outbreak: The area within 50
kilometers from infected farm is on intensive surveillance. Any positive
farms will be depopulated and disinfected.
3. Movement control: Movement of avian species from the
area within 60-kilometer radius is not allowed for at least 30 days.
4. Public awareness campaign: Information, recommendation
and guidelines are distributed to facilitate cooperation and create good
understanding from industry and the community.
After stamping-out of the last affected premise the following plans will
be executed in order to assure freedom from disease and, later, to monitor
the existence of the virus and early detection of disease.
• Tracing and surveillance: After repopulation of the affected
areas, surveillance will be carried out for 5 months to confirm freedom
• Surveillance and monitoring: After freedom from disease
is assured active and passive surveillance for AI will be carried out in
order to obtain epidemiological information for prevention and control.
Emergency Response for Avian Influenza
Outline of this document
|Phase I : During the outbreak
||Policy and strategies
- Pre-emptive stamping-out
- Surveillance during the outbreak
- Movement control
- Public awareness
||Public awareness campaign
|Phase II : Post-outbreak
|| Principle and strategy
|Phase III : Long term surveillance
||Principle and strategy
|| National surveillance plan for avian influenza
|The Sanitary Chicken Project
|The National Surveillance Plan for AI
|Results of AI surveillance 1997-2002 (publication)
Phase I : During the outbreak
Policy and strategies
Highly pathogenic avian influenza (HPAI) is a disease in “List A” of Office
of International Epizooties (OIE) because of its highly pathogenic nature
and destructive impact on trade. The policy set by the Department of Livestock
Development, Ministry of Agriculture and Cooperatives is eradication of
the disease as fast as possible to minimize potential damages. HPAI is
enlisted in the highly contagious diseases under the Animal Epidemic Act
B.E. 2449 (A.C. 1956) and its reversion in B.E. 2542 (A.C.1999), which
allows strategic actions of stamping-out, quarantine, movement control,
compensation and other necessary measures possible.
These criteria are established in order for early detection of the disease.
Target animals include chicken, duck, quail and other avian species presented
with the following clinical signs.
1. Severe respiratory signs with excessively watery eyes and sinusitis,
cyanosis of the combs, wattle and shanks, edema of the head, ruffled feathers
2. Diarrhea and nervous signs
3. No noticeable signs but sudden death of almost 100%, or cumulative
death approximately 40% within 3 days
If one of the above criteria is observed, the disease control measures
must be executed immediately.
- Pre-emptive stamping-out If suspected case is identified,
that premise will be quarantined. Samples will be collected and analyzed
for avian influenza and other possible pathogens. If HPAI is confirmed,
that particular premise will be depopulated and disinfected. All premises
within 5-kilometer radius from the index farm will be depopulated and
- Surveillance during the outbreak The area within 50
kilometers from infected farm is on intensive surveillance. Cloacal swabs
will be collected and analyzed for the virus. If the virus is detected
that infected farm will be depopulated and disinfected. Other premises
in this zone (50 km. radius) are on quarantine.
- Movement control Movement of avian species and their
products from the area within 60-kilometer radius from infected farms
are prohibited. Checkpoints will be set up by the DLD to enforce the regulations.
- Public awareness campaign Information, recommendations
and guidelines will be distributed to private sector, risk groups and
general public to raise awareness and good understanding of the community.
Principle and strategy
Repopulation of affected areas will be considered if no new case or death
is detected 21 days after destruction of the last affected premise. If
repopulation is allowed surveillance will be carried out for 5 months
to confirm freedom from disease.
Surveillance in the areas other than control zone (50 km. radius) includes
testing of the flocks that show any clinical signs fit in the case definition.
Virological and/or serological investigations will be conducted.
For control zone, sample collection for virological assays will be carried
out in flocks at 30 days after repopulation, before selling and/or at
5 months to establish a 95% confidence of detecting infection in the flocks
at less than 5%. Examination for AI includes twice weekly clinical examinations
for 30 days then every two-week for 5 months, identification of virus
or other pathogen will be performed on dead birds. Positive flock, if
any, will be depopulated and disinfected. Necessary measures will be undertaken
immediately to control the disease.
Post-outbreak surveillance entitled “Sanitary chicken project” is attached
as appendix 1.
Phase III : Long term surveillance
Principle and strategy
Highly pathogenic avian influenza (HPAI) had never been reported in Thailand
until January, 2004. Although, active and passive surveillance have been
conducted since 1997 HPAI outbreak was unexpectedly occurred and spread
widely (see appendix 3 for the publication). Stamping-out strategy was
executed however carrier birds or migratory birds cannot be completely
destroyed. For these reasons epidemiological information is very crucial
in order for early detection of the disease. This objective can only be
achieved by strengthening of surveillance.
National surveillance plan for avian influenza
National surveillance plan for AI is a long tern project which composed
of active and passive surveillance. Budget will be granted by the Government
Description of the plan is attached as appendix 2.
|Bureau of Disease Control and Veterinary Services