(Date of previous outbreak of highly pathogenic avian influenza in Pakistan reported to the OIE: 2000).

Information received on 28 January 2004 from Mr Rafaqat Hussain Raja, Animal Husbandry Commissioner, Ministry of Food, Agriculture and Livestock, Islamabad:

Date of the report: 27 January 2004.

Nature of diagnosis: clinical, post-mortem and laboratory.

Date of initial detection of animal health incident: 19 January 2004.

Estimated date of primary infection: 15 January 2004.

Three outbreaks of avian influenza were reported in the state of Karachi, Sindh province.

Description of affected population: layer hens in commercial farms.

Total number of animals in the outbreaks:

susceptible: 6.4 million.

cases: 2.5 million.

deaths: 1.2 million.

slaughtered: 0.5 million.

Diagnosis:

A. Laboratories where diagnosis was made:

- National Animal Sciences Institute, Pakistan Agriculture Research Institute, Islamabad.

- Veterinary Research Institute, Lahore and National Veterinary Laboratory, Islamabad.

Samples have been submitted to the Reference Laboratory in the United Kingdom for confirmation.

B. Diagnostic tests used:

- inoculation into embryonated SPF fowl eggs,

- agar gel immunodiffusion test,

- haemagglutination and haemagglutination inhibition tests,

- agar gel precipitation test.

Laboratory diagnosis was made on 25 January 2004.

C. Causal agent: H7 strain of avian influenza virus was detected.

Source of agent / origin of infection: investigations are underway.

Control measures:

- All the birds at the affected farms have been quarantined and vaccinated against avian influenza.

- Zoosanitary measures have been instituted and movements of the animals have been restricted.

- Control of wild reservoirs.

- Zoning.

- The Livestock Department of Sindh has been asked to further investigate the area of origin of infection.