OIE: Highly pathogenic avian influenza, Hong Kong (P.R. China)

Information received on 13/02/2009 from Dr Thomas Sit, Assistant Director , Inspection & Quarantine, Agriculture, Fisheries and Conservation Department, Cheung Sha Wan , Hon Kong , Hong Kong (P.R. China)

Summary

Report type Immediate notification
Start date 29/01/2009
Date of first confirmation of the event 31/01/2009
Report date 13/02/2009
Date submitted to OIE 13/02/2009
Reason for notification Reoccurrence of a listed disease
Date of previous occurrence 01/2009
Manifestation of disease Sub-clinical infection
Causal agent Highly pathogenic avian influenza virus
Serotype H5N1
Nature of diagnosis Laboratory (advanced)
This event pertains to the whole country

New outbreaks

Summary of outbreaks Total outbreaks: 10
Outbreak Location and Affected population
  • HONG KONG (Sha Lo Wan; Sha Lo Wan; Sha Lo Wan; Sham Wat Wan; Butterfly Beach, Tuen Mun; San Shek Wan; Tai O; Mai Po; Yau Kam Tau; Lantau Island) : 1 goose and 1 duck at the coast
Total animals affected
Species Susceptible Cases Deaths Destroyed Slaughtered
Birds 9 9
Wild species 3 3
Outbreak statistics
Species Apparent morbidity rate Apparent mortality rate Apparent case fatality rate Proportion susceptible animals lost*
Birds ** ** 100.00% **
Wild species ** ** 100.00% **

* 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
  • Unknown or inconclusive
Epidemiological comments An intensive surveillance system is in place on all poultry farms, poultry markets, pet bird shops, park birds and wild birds in Hong Kong.
Poultry carcasses from unknown sources were detected along the western coast of Hong Kong since 29 January 2009. Most of the carcasses were badly decomposed at the time of collection and sampling.
Since February 2006, the HKSAR Government has banned backyard poultry farming and daily rural patrols throughout the territory have been put in place since then. This activity has been enhanced since the occurrence of the event. No poultry farm or backyard poultry farming activities were detected within the 3-km-radius affected zones. The monitoring on local poultry farms was also enhanced and no irregularity was detected. Investigations on the source of the poultry are ongoing.

The three H5N1 positive wild birds were detected in our ongoing surveillance program on wild birds. No spread of disease was evident.
The affected Mai Po nature reserve is closed for 21 days from 5 February 2009.

Control measures

Measures applied
  • Screening
  • Disinfection of infected premises/establishment(s)
  • No vaccination
  • No treatment of affected animals
Measures to be applied
  • No other measures

Diagnostic test results

Laboratory name and type Department of Microbiology, University de Hong Kong (National laboratory)
Tests and results
Species Test Test date Result
Birds gene sequencing Pending
Birds gene sequencing 06/02/2009 Positive
Wild species gene sequencing Pending
Laboratory name and type Tai Lung Veterinary Laboratory Agriculture, Fisheries and Conservation Department (National laboratory)
Tests and results
Species Test Test date Result
Birds immunohistochemical test 31/01/2009 Positive
Birds polymerase chain reaction (PCR) 31/01/2009 Positive
Birds virus isolation 04/02/2009 Positive
Wild species immunohistochemical test 05/02/2009 Positive
Wild species polymerase chain reaction (PCR) 05/02/2009 Positive
Wild species virus isolation 07/02/2009 Positive

Future Reporting

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