If there is no outbreak of the disease for three consecutive months, a country can declare itself free from bird flu.

The last outbreak of the highly pathogenic H5N1 avian influenza was reported on September 19, 2011, from Betai Nanshatola and Putimari Christianpara in Tehetta Block of Nadia district, West Bengal. There were 849 deaths of birds in rural backyard poultry, reports The Hindu.

Before that, India had declared an outbreak on September 8, 2011, at Bhamondanga village, part- I, Agomoni Block in Dhubri district of Assam. There were 1,436 deaths in rural backyard poultry and as many as 15,409 birds were culled in the vicinity.

The control measures adopted were stamping out of the entire poultry population, including destruction of eggs, feed, litters and other infected materials in a radius of 3 km around each outbreak location, restriction on movement of poultry and poultry products to and from the area of outbreak, disinfection and cleaning up of infected premises. The final disinfection process was completed in September 2011.

Following the procedure, surveillance was carried out throughout the country. Surveillance around the area of outbreak since completion of the operation (including culling disinfection and clean up) and surveillance in the rest of the country has shown no evidence of bird flu in the last three months.

The bird flu-free declaration is essential to re-building the export market in the sector.