Highly pathogenic avian influenza,
Thailand

Information received on 25/04/2008 from Dr Sakchai Sriboonsue, Director General , Department of Livestock Development, Ministry of Agriculture and Cooperatives , Bangkok, Thailand

Summary

Report type Follow-up report No. 5 (Final report)
Start date 08/01/2008
Date of first confirmation of the event 22/01/2008
Report date 25/04/2008
Date submitted to OIE 25/04/2008
Date event resolved 13/02/2008
Reason for notification Reoccurrence of a listed disease
Date of previous occurrence 06/2007
Manifestation of disease Clinical disease
Causal agent Highly pathogenic avian influenza virus
Serotype H5N1
Nature of diagnosis Suspicion, Clinical, Laboratory (advanced), Necropsy
This event pertains to a defined zone within the country
Related reports
Outbreaks There are no new outbreaks in this report

Epidemiology
Source of the outbreak(s) or origin of infection
  • Under investigation
Epidemiological comments Poultry within the infected premises were immediately depopulated. A total of 53,688 chickens were destroyed on site and 5,120 birds in the surrounding area of the infected premises were culled to reduce all potential risks.

Movement of animals within a 10-km-radius zone from the infected premises was prohibited. Seven and 19 checkpoints were set up in Nakhon Sawan and Phichit, respectively, to ensure that the movement control was effective. The movement control was in place for at least 30 days following completion of stamping-out and disinfection, providing that no further suspicion of HPAI was identified. A total of 492,080 poultry in 1,290 premises was put under quarantine throughout the period.

Active surveillance using clinical case definition was carried out in every household within a 10-km-radius zone from the infected premises. Samples were collected within a 5-km-radius zone. One hundred and fifty-one cloacal swab samples (from 755 poultry) and 83 cloacal swab samples (from 415 poultry) were collected from Nakhon Sawan and Phichit, respectively, as part of the active surveillance in infected areas.
Targeted surveillance in compliance with the Appendix 3.8.9 of the OIE Code was carried out from 1 to 29 February 2008 in Thailand. The risk areas were defined as areas with history of AI outbreaks, wet land, high density of poultry population kept in sector 3 and 4, and certain risk species. During the targeted surveillance, a total of 47,889 cloacal swab samples (from 239,445 birds) were collected. All collected samples were tested negative for HPAI. Laboratory tests were performed at official laboratories of the Department of Livestock Development (DLD) using virus isolation, RT-PCR, and real-time RT-PCR according to the OIE protocol.

Thorough disinfection was implemented within a 5-km-radius zone around the infected premises and also in areas with higher risk, using OIE recommended disinfectants.

Avian influenza vaccination in poultry is prohibited in Thailand.

Results from the surveillance provide sufficient evidence that there has been no further HPAI infection in Thailand. Three months have elapsed since the completion of stamping out and disinfection of infected premises, which was on 25 January 2008. Thailand declares therefore having regained its status of HPAI free country according to the Article 2.4.12.4 of the OIE Terrestrial Animal Health Code.

Control measures
Measures applied
  • Stamping out
  • Quarantine
  • Movement control inside the country
  • Screening
  • Zoning
  • Disinfection of infected premises/establishment(s)
  • Dipping / Spraying
  • Vaccination prohibited
  • No treatment of affected animals
Measures to be applied
  • No other measures

Future Reporting
The event is resolved. No more reports will be submitted.