Survey of a school outbreak of 2009 pandemic influenza A (H1N1) caused by imported case

To evaluate the control of a 2009 pandemic influenza A(H1N1) outbreak in an international school, and provide scientific evidence for the control of 2009 pandemic influenza A(H1N1) outbreak. Non pharmaceutical interventions, such as school closure, isolation and treatment of cases, were carried out. A questionnaire survey was conducted among the students and teachers to identify the infection source. Throat swabs were taken form the all cases for testing. The outbreak was caused by an imported case from Singapore. Twelve cases of 2009 pandemic influenza virus infections were reported during this outbreak lasted for 8 day. The attack rate was 2.61% (12/460). The generation time was 65.2 hours (range 32-96 hours) .School was closed for 7 days when attack rate reached 0.89% (4/46). The outbreak was caused by an imported case. Early school closure (attack rate﹤1%) could effectively control the outbreak of 2009 pandemic influenza A (H1N1), and provide theoretical evidence for the control of influenza pandemic .