PATNA, Feb. 23 -- Fresh deaths of crows in Patna and Bhagalpur have raised concerns over a possible spread of the H5N1 avian influenza or bird flu, prompting the Bihar government to intensify containment and biosecurity measures across five affected districts, officials said on Sunday. Authorities have collected fresh samples from areas around the Patna high court, the Indira Gandhi Institute of Medical Sciences (IGIMS), AG Colony and Mokama in Patna district, and Sultanganj in Bhagalpur district. "We have sent fresh samples for testing to the Regional Disease Diagnostic Laboratory (RDDL) in Kolkata on February 19 after about 68 crow deaths were reported between February 16 and 18 in different localities of Patna and Bhagalpur," said Shirsat Kapil Ashok, secretary of the state animal husbandry and fisheries department. Samples from AG Colony and IGIMS have tested negative for the H5N1 virus, while reports from other areas of Patna are awaited. The state has so far confirmed 366 crow deaths due to the highly pathogenic H5N1 avian influenza since January 28. The fatalities were reported from Darbhanga (200), Bhagalpur (70), Katihar (62), Patna (22) and Bettiah in West Champaran district (12), said Ashok. Samples were initially examined at RDDL Kolkata and later sent to the National Institute of High Security Animal Diseases (NIHSAD), Bhopal, for confirmatory testing before the outbreak in crows was officially declared. The government has stepped up sanitisation and surveillance in affected areas. "Antiviral drugs, personal protective equipment and disinfectants - including sodium hypochlorite and glutaraldehyde, both recognised virucidal agents against avian influenza - have been supplied to all 38 districts. We are alert in case of poultry," said Ashok. Dr Deepak Kumar, research officer at the Institute of Animal Health and Production (IAHP), said, "We have fumigated areas within a 1-km radius of the epicentre of crow deaths and strengthened biosecurity measures. Trees are being pruned to discourage migratory birds from roosting, and people have been advised to avoid unnecessary movement in affected localities," said . Dr Kumar attributed the spread to migratory birds, which arrive in the state between October and March....