A woman who died this past week in Shanghai tested positive for the virulent H5N1 strain of bird flu, the Chinese government said Saturday. It was the Chinese mainland's 11th confirmed human death from bird flu and the first in Shanghai, the country's biggest city, according to the World Health Organization. The migrant worker, who was identified only by the common surname Li, died Tuesday at a Shanghai hospital after suffering a fever and cold symptoms. Blood tests by China's national Center for Disease Control confirmed Li had bird flu, the Health Ministry said in a statement carried by the official Xinhua News Agency. It said the tests were conducted in line with WHO standards and results were reported to the agency.