Countries affected by the deadly avian influenza virus H5N1 should not restock their flocks too quickly in order to avoid the disease flaring up again, the UN Food and Agriculture Organisation (FAO) has warned.

Two months after the outbreak of the epidemic some countries are already planning to declare selected zones disease-free and to restock decimated flocks, the FAO said.

“In the battle against the disease, there are definitely some improvements. But we fear that the virus may continue to circulate in the environment even without an outbreak or any clinical signs in animals,” said Joseph Domenech, chief of the Animal Health Service.

“Appropriate precautionary measures have to be put in place to be absolutely sure that infected zones are free from infection and will remain free,” he added.

Before restocking, countries will have to prove the absence of virus circulation, monitor the movement of poultry and contaminated goods to avoid the reintroduction of the virus from affected areas, prevent contact between domestic and wild birds, and apply intensive disease surveillance to ensure potential new infections are discovered immediately, the FAO said.

If countries want to resume exports they will have to prove that they are free from bird flu. Their status will be verified by independent international experts.

The FAO added that in some countries more information about the spread of the disease should be made available to the international community.