On May 27 2009, Singapore confirmed its first case of Influenza A (H1N1-2009). The patient, a 22 year-old Singaporean female is currently being treated at the Communicable Disease Centre at Tan Tock Seng Hospital (TTSH) and is in stable condition. She was in New York from May 14- 24 and arrived back in Singapore on 26 May at 06.30hrs. She began to develop a cough while onboard. Later in the morning, she consulted a GP who decided to send her to TTSH via a 993 ambulance, given her travel history. She was immediately admitted for testing. Laboratory confirmation of her infection was made by midnight of 26 May. 
As of May 27, 5pm, Singapore had the first confirmed case and three additional suspect cases for investigations today. Of the 48 cases investigated thus far, 1 case has tested positive for the Influenza A (H1N1-2009) virus, 39 cases tested negative for Influenza A, and 8 tested positive for the usual circulating seasonal flu strains. 
As of May 27, the Disease Outbreak Response System is at alert Yellow, the second alert of a 5 colour system.
Singapore's Minister of Health Khaw Boon Wan has urged citizens to limit travel to affected areas such as Mexico and the United States. The Health Ministry has advised the public to seek immediate medical attention if they experience influenza symptoms within seven days after arriving from affected areas, to maintain good hygiene, and for those who are sick with respiratory illnesses to avoid crowded areas and wear masks.