PATNA, Feb. 26 -- Around 5,000 poultry birds were culled on Wednesday at the Bihar government's poultry research station under the Bihar Animal Sciences University (BASU) after confirmation of H5N1 avian influenza, commonly known as bird flu, in Kaushal Nagar area of Chitkohra locality in Patna, said officials. The culling drive was launched following a notification issued by the state's dairy, fisheries and animal resources department on Tuesday after bird flu was confirmed on Monday. "About 5,000 poultry birds, 10,000 eggs and 550 kg of poultry feed were destroyed as part of the culling exercise," a farm official said. The culled birds and eggs were buried in three large pits dug at the site and covered with lime and bleaching powder. The area has been declared a prohibited zone. Eight rapid response teams, comprising around 20 veterinary doctors and 50 workers, carried out the operation between 10 am and 4.30 pm. Over 4,500 birds had died at the farm during the last fortnight, prompting the authorities to send samples for testing. Samples from the affected poultry were sent to the Regional Disease Diagnostic Laboratory in Kolkata for testing on February 11 that confirmed the presence of H5N1 virus. Officials said the department acted swiftly after receiving the confirmatory report on Monday and ordered immediate culling. Sanitation measures will begin from Thursday within a 1-km radius of the epicentre. The drive will include spraying of antiviral agents and disinfectants such as sodium hypochlorite and glutaraldehyde, both recognised as effective virucidal agents against avian influenza. Officials said the virus spread from infected crows to poultry birds. The first bird flu-related death in the state this year was reported in a crow on January 28. More than 400 crow deaths have since been recorded across five districts - Darbhanga, Bhagalpur, Katihar, Patna and Bettiah in West Champaran. Authorities attributed the spread of the virus to migratory birds acting as carriers....