One of two people confirmed by the Ministry of Health to have contracted avian influenza H5N1 died in a hospital in southwest China's city of Guiyang Wednesday morning. The patient, a 21-year-old woman, died of multiple organ failure at the Guizhou Provincial People's Hospital at 9:41 a.m. Wednesday, Xinhua reported. The woman and the other patient, a 31-year-old man, are both Guiyang residents. They developed symptoms on Feb. 2 and 3, respectively. Both of them tested positive for the H5N1 virus on Sunday, according to the ministry. Epidemic control experts have not found any indication that the patients had close contact with birds, nor have they found any epidemiological connection between the two cases. People who have had close contact with the two patients have been put under medical observation. None have exhibited symptoms. The human-transmissible form of avian influenza, also known as bird flu, is an acute respiratory infectious disease mainly caused by the deadly H5N1 virus subtype. Main symptoms include high fever and pneumonia. Human infections of bird flu are usually caused by transmission from poultry to humans. There have been no reported cases of sustained human-to-human transmission.