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

New outbreaks

Outbreak 1	Nalae village, Nalae village, Xay, OUDOMXAY
Date of start of the outbreak	01/09/2008
Outbreak status	Resolved (29/12/2008)
Epidemiological unit	Village
Affected animals	Species Susceptible Cases Deaths Destroyed Slaughtered Birds 1170 23 23
Affected Population	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.
Outbreak 2	Fa village, Fa village, Nambak, LUANGPRABANG
Date of start of the outbreak	27/08/2008
Outbreak status	Resolved (29/12/2008)
Epidemiological unit	Village
Affected animals	Species Susceptible Cases Deaths Destroyed Slaughtered Birds 5422 247 197 5225 0
Affected Population	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.
Summary of outbreaks	Total outbreaks: 2
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.

Map of outbreak locations

Location of current outbreaks

Click on map to zoom in.