Officials in Taiwan say they are monitoring hundreds of people who may have had contact with a tourist from mainland China infected with the H7-N9 strain of bird flu.
The man, 86, from the eastern Chinese province of Jiangsu, is in hospital in Taiwan.
The BBC reports as many as 500 people may have had contact with him, all of whom are being asked to report to doctors should they develop possible symptoms.
Among those who have had contact are three medical personnel, who have shown symptoms of upper respiratory tract infections and are taking medicine.