Taiwan on Wednesday reported the first case of the H7N9 bird flu outside of mainland China.
The 53-year-old man, who had been working in the eastern Chinese city of Suzhou, showed symptoms three days after returning to Taiwan via Shanghai, the Centers for Disease Control (CDC) said, adding that he had been hospitalised since April 16 and was in a critical condition.
"This is the first confirmed H7N9 case in Taiwan who was infected abroad," Health Minister Chiu Wen-ta told reporters.
The patient said he had not been in contact with poultry or eaten under-cooked birds or eggs while staying in Suzhou, Chiu added.
The CDC warned people to avoid touching and feeding birds and visiting traditional markets with live poultry when visiting Chinese regions with H7N9 cases.
Taiwanese authorities said they were monitoring 139 people who had had contact with him, including 110 hospital workers in three hospitals.
Earlier this month Taiwanese authorities destroyed more than 100 birds smuggled from the mainland and seized by the coastguard in a fishing port in northern Taiwan.
China has confirmed 108 cases and 22 deaths since the first infections were announced on March 31, with a higher proportion of cases in older people.