The deadly H5N1 bird flu virus is spreading among poultry farms around northern Nigeria´s largest city, a senior veterinary official said Sunday.

"The avian influenza virus is still spreading among poultry farms and it has so far affected 33 farms in seven districts," Shehu Bawa, head of Kano State´s Committee on Avian Flu, told AFP.

More than 80,000 birds have been culled in Kano, Bawa added.

Further measures taken to check the outbreak include controls on movement of poultry and people, disinfecting farm workers and visitors, fencing off farms, and a ban on borrowing of farm implements from them.

Nigeria, the continent´s most populous nation with some 140 million people, early this year reported west Africa´s first human bird flu death.

A 22-year-old woman died in Lagos on January 17 weeks after plucking and disembowelling a chicken.Bird flu was first detected on a farm in Jaji town outside the northern city of Kano in February last year from where it spread to other parts of Nigeria.

Kano, northern Nigeria´s most populous city, was worst affected by the flu outbreak which ravaged 97 farms in the city resulting in the death or culling of at least 300,000 birds, officials said.

Three more northern states -- Katsina, Sokoto and Bauchi -- have recorded a resurgence of bird flu since it resurfaced in Kano.

Bawa expressed the hope that the resurgence of the disease in Kano would not be as bad as the first outbreak, in an apparent attempt to douse public fears.

"I think the resurgence will not be as devastating as the initial outbreak because while 33 farms have been infected in the last four months, since December, the virus ravaged 97 farms within the same period in the February 2006 outbreak," Bawa said.

"Improved bio-security measures by farmers is mainly responsible for slow rate of spread of the avian influenza virus coupled with the review of compensation to be paid to farmers who lost their chickens from 250 naira (two dollars) to 500 naira (four dollars), based on the WHO recommendations", he said

According to Nigeria´s Department of Veterinary Research, a total of 945,862 birds were lost since the bird flu outbreak in February last year out of which 602,160 were depopulated.