Objective To find out the source of the Avian-human Influenza infection case. Methods The following aspects of the case were investigated, which include the process of falling ill, treatment, exposure and so on. People who closely contacted with the patient or died avian were observed. Results Since March 5th,a lot of fowls died in the country where the patient lived. The patient had touched the died avian and its secretion or egesta before falling ill. And avian influenza H_5N_1 virus was found in the case...