This is important:

During March 28 and April 9, 2013, the patient traveled to Suzhou. On April 9, he returned to Taiwan from Shanghai. According to the case, he had not been exposed to birds and poultry during his stay in Suzhou and had not consumed undercooked poultry or eggs. On April 12, he developed fever, sweating, and fatigue, but no respiratory or gastrointestinal symptoms. On April 16, he sought medical attention at a clinic when he developed high fever and was transferred to a hospital by the physician. He was then hospitalized in a single-patient room for further treatment. On April 16, he was administered Tamiflu. On April 18, his chest x-ray showed interstitial infiltrate in the right lower lung. On the night of April 19, his conditions worsened. On April 20, he was transferred to a medical center for further treatment. He was then intubated due to respiratory failure and placed in the negative-pressure isolation room in the intensive care unit. During his stay in the hospitals, two throat swab specimens were collected and both tested negative for avian influenza A (H7N9) virus by real-time RT-PCR. On April 22, the medical center collected a sputum specimen from the patient and the specimen was tested positive for influenza A. In the morning of April 24, avian influenza A (H7N9) virus was detected in the sputum specimen using real-time RT-PCR. In the later afternoon of April 24, the National Influenza Center in Taiwan confirmed the identification and completed the genome sequencing of the virus.

[link to www.cdc.gov.tw]