The first H7N9 bird flu patient in Beijing, a girl surnamed Yao, accompanied by her parents, receives a certificate from Ditan Hospital for her brave composure during her hospitalization there. Yao was discharged on Wednesday. Wang Jing / China Daily
As of Wednesday, China has reported 82 human infections of H7N9, including 17 deaths. About 40 percent of the patients had no contact with poultry or environments where birds were located, previous epidemiological studies found. It remains a mystery how they became infected, Zeng said.