The GPO has contacted Siriraj Hospital's Faculty of Medicine about conducting a bio-equivalence study on the GPO medicine and an imported bird flu drug, Deputy Public Health Minister Anutin Charnveerakul said yesterday.

"The study will take one or two months," Anutin said, adding that the GPO would register the bird flu medicine with the Food and Drug Administration as soon as the study was completed before it could be given to patients, Anutin said.

He urged people who regularly have close contact with poultry to take preventive measures, as bird flu outbreaks were more likely in the rainy season.

In a related development, Sompong Nimnuan, livestock chief of Phichit's Sam Ngam district, said his team had already exterminated nearly 200 chickens in a village in Tambon Nong Sone after many birds died mysteriously.

"We have to take preventive measures because bird flu has erupted around here recently," Sompong said.

Some chickens have already been sent for lab tests, the results of which should be available next week, he added.

Phichit deputy livestock chief Thammanoon Thongsuk said officials would cull birds in areas where large numbers had died under mysterious circumstances.

"We offer compensation for exterminated birds," the agricultural official said.