EVALUATION OF IMPACT OF JAPANESE ENCEPHALITIS VACCINE IN CAMBODIA

描述（由申请人提供）：根据其频率和严重程度，日本脑炎（JE）病毒是亚洲儿童脑炎的最重要原因。这是一种严重的疾病，病死率高达30%，另外30-50%的儿童会有后遗症。乙脑是柬埔寨的一种地方病，监测表明乙脑至少占15岁以下儿童脑膜脑炎病例的20%。虽然没有治愈乙脑的治疗方法，但这种疾病是可以预防的。一种安全、有效、负担得起的乙脑疫苗，即SA 14-14-2乙脑减毒活疫苗，在亚洲日益普及。这项工作的目的是证明使用这种疫苗的乙脑免疫接种运动的影响。柬埔寨一个省将加强以人口为基础的脑膜脑炎监测，以确保在免疫接种前获得关于发病率的良好数据。在收集了至少一年的监测数据后，将在该省为高危儿童开展乙脑疫苗接种运动。该运动将针对15岁以下的儿童，这是最有可能患病的年龄组。运动后至少一年收集的监测数据将显示乙脑疫苗预防脑膜脑炎的比例。在同一时期，还将在没有接种疫苗的邻省监测脑膜脑炎的发病率。项目活动将展示使用SA 14-14-2乙脑疫苗开展大规模乙脑免疫运动对脑膜脑炎和乙脑发病率的真正影响。这一信息对柬埔寨、考虑引进疫苗的其他乙脑流行国家以及为改善亚洲乙脑控制提供技术支持或资源的组织都是有用的。这些组织包括世界卫生组织（世卫组织）、联合国儿童基金会、全球疫苗和免疫联盟（GAVI）以及其他政府和非政府组织。

DESCRIPTION (provided by applicant): Japanese encephalitis (JE) virus is the most important cause of encephalitis in children in Asia based on its frequency and severity. It is a serious disease with a case fatality rate of up to 30% and sequelae in a further 30-50% of children. JE is an endemic disease in Cambodia, with surveillance demonstrating JE causes at least 20% of all cases of eningoencephalitis in children fewer than 15 years of age. Although there is no curative treatment for JE, the disease is vaccine-preventable. A safe, effective, affordable JE vaccine, the live, attenuated SA 14-14-2 JE vaccine, is increasingly becoming available in Asia. The aim of this work is to demonstrate the impact of a JE immunization campaign utilizing this vaccine. Population-based meningoencephalitis surveillance in one province in Cambodia will be strengthened to ensure good data are available on disease rates before immunization. Following collection of at least one year of surveillance data, a JE vaccination campaign for at risk children will be implemented in this province. The campaign will target children under 15 years of age, the age group at highest risk of disease. Surveillance data gathered for at least one year after the campaign will demonstrate the proportion of meningoencephalitis prevented by JE vaccine. Rates of meningoencephalitis over the same period will also be monitored in a neighboring province without vaccination. The project activities will demonstrate the true impact on rates of meningoencephalitis and JE of a mass JE immunization campaign with SA 14-14-2 JE vaccine. This information will be useful within Cambodia, for other JE-endemic countries considering vaccine introduction, and for organizations providing technical support or resources to improve control of JE in Asia. These organizations include the World Health Organization (WHO), UNICEF, The Global Alliance for Vaccination and Immunization (GAVI), and other government and non-government organizations.