In view of bird flu cases being detected in three districts of Karnataka, the administration is carrying out mass culling, while ramping up its surveillance across the state, especially in districts bordering Andhra Pradesh and Telangana, officials said on Saturday. Avian influenza (AI), also known as bird flu, is a zoonotic viral disease that primarily affects poultry and may occasionally spillover to mammals, including humans and swine, they said. Cases of bird flu among poultry birds have been reported in Manvi taluk of Raichur, Chikkaballapur taluk of Chikkaballapur and Sandur taluk of Ballari districts, they said. However, no cases of bird flu in humans have been reported in the state so far, officials said. Ansar Ahmed, project director, integrated disease surveillance programme, told PTI that H5N1 was confirmed in the Regional Poultry Breeding and Training Centres of Kurekuppa, Ballari District and Chikkaballapur District at NIHSAD Lab, Bhopal on February 25. The matter was