Blood-serum tests aimed at boosting Hong Kong's defences against the deadly H7N9 bird flu virus have so far returned no positive results, authorities on both sides of the border say.
The tests, showing whether chickens have been exposed to the H7 virus of which H7N9 is a strain, indicate whether the farms the birds come from are or have been infected.
In Hong Kong, the Agriculture, Fisheries and Conservation Department said 90 samples taken from a group of 12,000 chickens raised at three farms in the New Territories all tested negative.
Samples are being taken both from chickens raised on local farms and the 7,000 chickens imported on a daily basis. None of the local birds have tested positive, and last night the Food and Environmental Hygiene Department said all 120 samples taken from imported birds at the border had tested negative.
Across the border, a first batch of 56 samples taken on Wednesday had also tested negative, said Lo Wei, deputy chief of the Shenzhen Inspection and Quarantine Bureau's animal quarantine division.
"Our agreement with Hong Kong includes running [serum] tests on live poultry supplied to Hong Kong," Lo said. "Should there be positive test results, we would immediately halt supply to Hong Kong."