On May 22, 2009, the Central Epidemic Command Center (CECC) confirmed the forth and fifth imported case of influenza A (H1N1) in Taiwan. The forth case is a 30-year-old, Taiwan-born female who traveled to Manila, the Philippines to attend an international yoga workshop with her daughter, elder sister and a friend from May 16 to 20, 2009.The participants in the events were mostly from the United States, Canada and Australia.The case took flight PR896 and arrived at Taiwan at 09:30 on May 20, 2009.Before boarding the plane, the case experienced influenza-like symptoms such as lightheadedness and sore throat, but did not develop fever.Therefore, the case returned home after she arrived in Taiwan and had dinner at a friend’s house.On May 21, 2009, she put on a facemask and sought medical attention at a clinic because her symptoms persisted.Her doctor suspected that she was infected with influenza A (H1N1) and thus referred her to a hospital.At the hospital, she was diagnosed with a fever of 38℃, sore throat, and light cough, and was immediately sent to the negative pressure isolation room for treatment and specimen collection.In the evening of May 21, 2009, the case’s daughter developed fever and was sent to the hospital for treatment at the negative pressure isolation room.The case’s daughter has come into close contact with fiver of her family members.In addition, the public health personnel have visited the kindergarten the case’s daughter attends for epidemiological investigation in order to determine if school closure is necessary.

CECC urged the passengers sitting in the same row and in the 3 rows in front and behind the case and the crew members on flight PR896 (departed from Manila at 07:39 on May 20, 2009 and arrived at Taoyuan at 09:31 on the same day; the case’s plane seat: 23B) to voluntarily report themselves to the Taiwan Centers for Disease Control (Taiwan CDC) through the Communicable Disease Reporting and Consultation Hotline, 1922.After contacting Taiwan CDC, public health personnel will visit them to administer antiviral prophylaxis and request them to conduct self-health management: observe their own health, conduct home quarantine, and measure their body temperature twice a day for a period of seven days. If any of the close contacts develop influenza-like symptoms such as fever and cough during the next 2-7 days, please be sure to contact the local health unit first and refrain from seeking medical attention on his/her own.On the other hand, the passengers on board the same flight with the case should not be overly panicked and are urged to conduct self-health management for seven days or call 1922 for consultation.

The fifth confirmed case is the third confirmed case’s elder sister.Since the fifth case was sitting next to the third case on their flight back to Taiwan, the fifth case is a close contact of the third case.Therefore, the health authority voluntarily contacted the fifth case and considered the fifth case as an investigative case because she had developed influenza-like symptoms.In the early morning of May 22, 2009, the fifth case was immediately assisted to the hospital for medical attention and specimen collection.Later in the afternoon, influenza A (H1N1) infection was confirmed in the case. Currently, the case’s conditions have improved, but she remains at the negative pressure isolation room.Further, as the fifth case had sought medical assistance at a clinic after returning to Taiwan, CECC has contacted the clinic and conducted necessary precautions such as epidemiological investigation and outbreak control measures.