Details of the cases are as follows:

• A 61-year-old man from Yantai City, Shandong Province who became ill on 6 May, was admitted to a hospital on 10 May and subsequently died. The patient had exposure to live poultry. He is the father of the 33-year-old man described below.
• A 33-year-old man from Yantai City, Shandong Province who became ill on 16 May and was admitted to a hospital on the same day. He has mild symptoms of illness. The patient did not have exposure to live poultry. He is the son of 61-year-old man described above. He was living and caring for his father during his hospitalization.
• A 51-year-old man from Huaian City, Jiangsu Province, who became ill on 17 May and was admitted to a hospital on 25 May. He is currently in a severe condition. The patient had no exposure to live poultry.
• A 51-year-old woman from Changzhou City, Jiangsu Province, who became ill on 22 May and was admitted to a hospital on 27 May. She is currently in a critical condition. The patient had no exposure to live poultry.