In Cooch Behar district, the district's animal resources department sources said deaths of chicken were reported at Khalisamari of Mathabhanga-I block. ARD sources in the district said that bird deaths were reported from four blocks out of 12. These were Dinhata-I, Cooch Behar-I, Mathabhanga-I and Mekhliganj. In Haribhanga of Cooch Behar-I, carcasses of 10 migratory birds were found yesterday. The samples were sent to Kolkata.

The above comments describe birds deaths, including migratory birds, in West Bengal's northern district, Cooch Behar (see satellite map). The deaths of migratory birds by H5N1 would not be a surprise. Birds that spend the spring in central China at the Qinghai Lake reserve, or the summer in Siberia at Chany Lake, or Erhel or Uva Lakes in Mongolia, fly south to India in the winter.

The Qinghai strain of H5N1 was reported in bar-headed geese at Qinghai Lake in 2005 and 2006. Similarly, the Uva Lake variant was found at Uva Lake in the summer of 2006. The Uva Lake strain grew out of clade 2.2.3, which was reported in India and Afghanistan in 2006. Thus, it is likely that the Uva Lake strain is in India and Bangladesh at this time.

However, India has never reported H5N1 in migratory birds. Media reports of dead migratory birds in India are followed by minimal testing and a declaration of no H5N1 detected. In 2007 the Uva Lake strain was found in Europe during the summer, signaling more activity in the fall in Europe. That activity has been a predictor of enhanced activity in the winter, as was reported for Pakistan, India, and Bangladesh.

In addition to the dead migratory birds described above, two dead teals have been reported just outside of Calcutta. Similarly, dead resident wild birds have been reported in areas where H5N1 has been confirmed in domestic poultry.

Although some waterfowl die from H5N1 infections, most are asymptomatically infected and they serve as vectors for the spread of H5N1.

Therefore, sealing of borders is not likely to stop the spread of H5N1, which appears to have happened in Bihar and Jharkland.