Some chickens in a Shenzhen farm have been found to have respiratory tract disease, the Health Welfare & Food Bureau says, adding initial tests for avian influenza have been conducted with negative results.

It said the State General Administration of Quality Supervision, Inspection & Quarantine said 203 chickens died between April 3 and April 10 in the Po An farm which supplies Hong Kong. To prevent infection spread, 8,000 chickens have been culled in the two sheds in which the dead chickens were found.

The Shenzhen Entry-exit Inspection & Quarantine Bureau sent investigators to the farm on April 10, and found other chickens had no abnormal health conditions. They have also inspected other chicken farms in the vicinity and found no abnormal conditions.

The bureau said respiratory tract disease is common in chickens and does not affect humans. The incident has shown the notification mechanism between Hong Kong and the Mainland is working well, it added.