Ma Chao, Yan Shaohong, Su Qiru, Hao Lixin, Tang Shaopei, An Zhijie, He Yulong, Fan Guangfei, Rodewald Lance, Wang Huaqing
Chinese Center for Disease Control and Prevention, Beijing, China.
Chinese Center for Disease Control and Prevention, Beijing, China.
Vaccine. 2016 Dec 12;34(51):6539-6544. doi: 10.1016/j.vaccine.2016.02.051. Epub 2016 Jun 18.
Following implementation of China's 2006-2012 Action Plan for measles elimination, which led to a nadir of measles in 2012, a resurgence started in 2013 that continued into 2014. Measles typically is a disease that mainly affects children. We investigated a community outbreak in 2014 with measles virus transmission among adults without children serving as virus reservoirs. Our investigation highlights adult susceptibility to measles.
We conducted a retrospective active case search, and analyzed confirmed case data to describe person, place, and time characteristics of the outbreak. All individuals with measles with onset during the first 2 months of the outbreak were interviewed face-to-face to determine source(s) of infection and transmission route (from whom and to whom).
Among the 280 cases, 220 (77.6%) were among ≥20-year-old adults, 24 (8.6%) were among 8-23 month olds, 22 (7.9%) were among <8-month-old infants, and the remaining 14 (5.9%) were among 2-19 year olds. Of the 83 cases in the early stage of the outbreak, 41 (49.4%) were acquired in the community, 24 (28.9%) were acquired nosocomially, 13 (15.7%) were acquired by family contact, and 5 were imported. Among 44 clearly determined transmission linkages, 37 (84.1%) were adult to other age-group (these include 29 adult-to-adult, seven adult-to-child, and one adult-to-infant), six were from infants to adult and children, and one was child-to-child. Outbreak response immunization activities were implemented by non-selective supplementary immunization activities, with 51.3% of targeted 5-19-year-old children and adolescents, and 30.2% of targeted 20-49-year-old adults being vaccinated.
Despite high population immunity among children and adolescents following three rounds of measles vaccine supplementary immunization activities, sustained measles virus transmission still occurred among adults in this community. Adult measles immunity gaps might threaten measles elimination, highlighting the importance targeting susceptible adults during outbreak response immunization.
随着中国《2006 - 2012年消除麻疹行动计划》的实施，2012年麻疹发病率降至最低点，然而2013年麻疹疫情开始反弹，并持续到2014年。麻疹通常是一种主要影响儿童的疾病。我们调查了2014年一起社区麻疹疫情，此次疫情中麻疹病毒在无子女的成年人中传播，这些成年人成为了病毒储存宿主。我们的调查凸显了成年人对麻疹的易感性。
我们开展了回顾性主动病例搜索，并分析确诊病例数据，以描述疫情的人群、地点和时间特征。对疫情最初两个月内发病的所有麻疹患者进行面对面访谈，以确定感染源和传播途径（从谁那里感染以及传染给了谁）。
在280例病例中，220例（77.6%）为20岁及以上成年人，24例（8.6%）为8至23个月大的儿童，22例（7.9%）为8个月以下婴儿，其余14例（5.9%）为2至19岁儿童。在疫情早期的83例病例中，41例（49.4%）在社区感染，24例（28.9%）在医院感染，13例（15.7%）通过家庭接触感染，5例为输入性病例。在44个明确确定的传播链中，37例（84.1%）是从成年人传播到其他年龄组（包括29例成人之间传播、7例成人传播给儿童、1例成人传播给婴儿），6例是从婴儿传播给成人和儿童，1例是儿童之间传播。通过非选择性补充免疫活动开展了疫情应对免疫接种工作，目标人群中51.3%的5至19岁儿童和青少年以及30.2%的20至49岁成年人接种了疫苗。
尽管在三轮麻疹疫苗补充免疫活动后儿童和青少年群体免疫力较高，但该社区成年人中仍持续发生麻疹病毒传播。成人麻疹免疫缺口可能会威胁到麻疹消除工作，这凸显了在疫情应对免疫接种中针对易感成年人的重要性。
