OIE: Highly pathogenic avian influenza, Laos

Information received on 14/09/2008 from Dr Khambounheuang Bounkhouang , Directeur Général, Département de l´Elevage et des Pêches , Ministère de l´Agriculture et des Forêts , Vientiane, Laos

Summary

Report type Immediate notification
Start date 27/08/2008
Date of first confirmation of the event 04/09/2008
Report date 14/09/2008
Date submitted to OIE 14/09/2008
Reason for notification Reoccurrence of a listed disease
Date of previous occurrence 02/2008
Causal agent Highly pathogenic avian influenza virus
Serotype H5N1
Nature of diagnosis Laboratory (basic), Laboratory (advanced)
This event pertains to the whole country

New outbreaks

Summary of outbreaks Total outbreaks: 2
Outbreak Location and Affected population
  • OUDOMXAY (Nalae village, Nalae village, Xay) : The positive flock was discovered due to back tracing from Nambak outbreak. A surveillance zone of 5-Km-radius was drawn around the suspected farm in Oudomxay, from where the positive ducklings in Nambak originated, even though no positive animals were found on that farm. Very low daily mortality (2%) was reported during disease investigation in one flock in Nalae village. This flock also originated from the same farm. Animals originated from the same farm as infected Nambak flock.
  • LUANGPRABANG (Fa village, Fa village, Nambak) : Ducklings in a small commercial unit within a village with backyard poultry. They were purchased on 20 August 2008 and started to die on 27 August 2008 (about 4% and then increasing to 10% per day). Farmer reported it to the district officer on 1 September. Samples were confirmed to be positive for HPAI H5N1 on 4 September 2008. The declaration of the CVO and the provincial governor was made on 5 September 2008. The infected flock was culled on 4 September 2008 and culling within the 1-Km-radius zone around the control zone started on 5 September 2008. Culling was presumably completed on 12 September 2008 (backyard poultry). Legal purchase and movement from a farm in other province where illegal import is suspected. Investigation on that farm is on-going.
Total animals affected
Species Susceptible Cases Deaths Destroyed Slaughtered
Birds 6592 270 220 5225 0
Outbreak statistics
Species Apparent morbidity rate Apparent mortality rate Apparent case fatality rate Proportion susceptible animals lost*
Birds 4.10% 3.34% 81.48% **

* 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
  • Introduction of new live animals
  • Legal movement of animals
  • Illegal movement of animals

Control measures

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

Diagnostic test results

Laboratory name and type National Animal Health Centre, Avian Influenza Laboratory (National laboratory)
Tests and results
Species Test Test date Result
Birds real-time PCR 11/09/2008 Positive
Birds reverse transcription – polymerase chain reaction (RT-PCR) 04/09/2008 Positive

Future Reporting

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