The United Nations has praised the "swift and comprehensive' measures taken by India to bring under control the "worst-ever' outbreak of bird flu in West Bengal, while urging the country to maintain vigilance in view of similar incidents reported in its neighbourhood. Culling The U.N. Food and Agriculture Organisation's veterinary expert Mohinder Oberoi said intensive culling in the predominantly backyard poultry sector of West Bengal appeared to have stopped the disease in its tracks. Mr. Oberoi made the comment after a recent field trip to the affected areas, where no new outbreaks have been reported since February 2. FAO's Chief Veterinary Officer Joseph Domenech, however, urged the country to maintain intensive surveillance in high-risk areas as the possibility of new occurrences remained high. "The virus could still be present in the environment despite heavy slaughtering and extensive disinfection of affected areas, or it could be reintroduced from other countries,' he said. Praised The officials praised the national and State governments' political and financial commitment to stamp out the disease. They said public awareness campaigns, a strong command chain from districts to villages, compensation payments and an effective collaboration between animal and human health departments at field level were the key factors for the success.