Survey of a school cluster of influenza A (H1N1)

Since the first influenza A (H1N1) case was reported on 2 September 2009, 13 cases had been reported in a middle school in Xiuzhou district by 10 September, without severe case and death. The attack rate was 0.72% (13/1800). From 31 August (The date of new term starting) to 18 September, 41 cases of influenza like illness (ILI) were diagnosed, the attack rate was 2.28%. The incidence peak was during the first week of new term. Because of effective communication and prompt isolation the cases, the epidemic was controlled timely and effectively.