OIE: Highly pathogenic avian influenza, Japan

Information received on 02/12/2010 from Dr Toshiro Kawashima, CVO, Animal Health Division, Ministry of Agriculture, Forestry and Fisheries, Tokyo , Japan

Summary

Report type Immediate notification
Start date 27/11/2010
Date of first confirmation of the event 29/11/2010
Report date 02/12/2010
Date submitted to OIE 02/12/2010
Reason for notification Reoccurrence of a listed disease
Date of previous occurrence 01/04/2009
Manifestation of disease Clinical disease
Causal agent Highly pathogenic avian influenza virus
Serotype H5
Nature of diagnosis Clinical, Laboratory (basic), Laboratory (advanced), Necropsy
This event pertains to the whole country

New outbreaks

Summary of outbreaks Total outbreaks: 1
Location(s)
  • SHIMANE (Yasugi city)
Total animals affected
Species Susceptible Cases Deaths Destroyed Slaughtered
Birds 21606 57 57 21549 0
Outbreak statistics
Species Apparent morbidity rate Apparent mortality rate Apparent case fatality rate Proportion susceptible animals lost*
Birds 0.26% 0.26% 100.00% 100.00%

* Removed from the susceptible population through death, destruction and/or slaughter

Epidemiology

Source of the outbreak(s) or origin of infection
  • Unknown or inconclusive
Epidemiological comments An outbreak of HPAI was confirmed on 2 December 2010 in Shimane prefecture. The previous outbreak of HPAI in Japan started in April 2008. The event has been contained in the affected farm by control measures including stamping-out and movement restrictions.
On 29 November 2010, a local veterinary officer visited the farm immediately after notification from the owner. Although no remarkable increase of the mortality was recognized, the local veterinary service centre in the prefecture confirmed that 3 out of 5 samples taken from dead birds were influenza A virus positive by antigen-capture kits. On the same day, the centre confirmed the subtype was H5 by RT-PCR test.
On 1 December 2010, the National Institute of Animal Health affirmed an isolate was due to influenza A virus subtype H5 by HI test.
On 2 December 2010, the institute confirmed the cases as highly pathogenic avian influenza because the isolate caused 75 % mortality in 4-week-old chickens infected intravenously, and the amino acid sequence of the connecting peptide of the haemagglutinin was the same as that observed for the highly pathogenic avian influenza viruses isolated from faeces of wild ducks in Hokkaido in October 2008.
Killing of the susceptible animals started on 30 November 2010 and was completed on 2 December 2010. Incineration of the carcasses and disinfection of the farm are continuing.
A movement restriction zone was established within 10 km around the affected farm on 29 November 2010. In addition, the traffic around the affected farm was restricted. There are 4 poultry farms in addition to the affected farm in the zone. They are also under surveillance. A total of 13 disinfection stations were established in and around the restriction zone.

Control measures

Measures applied
  • Control of wildlife reservoirs
  • Stamping out
  • Quarantine
  • 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 Domestic Livestock Disease Identification Office (Local laboratory)
Tests and results
Species Test Test date Result
Birds reverse transcription - polymerase chain reaction (RT-PCR) 29/11/2010 Positive
Birds virus isolation 30/11/2010 Positive
Laboratory name and type National Institute of Animal Health (National laboratory)
Tests and results
Species Test Test date Result
Birds gene sequencing 02/12/2010 Positive
Birds haemagglutination inhibition test (HIT) 01/12/2010 Positive

Future Reporting

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