title: Measles vaccine coverage estimates in an outbreak three years after the nation-wide campaign in China: implications for measles elimination, 2013.
abstract: BACKGROUND
  China is approaching measles elimination, but indigenous measles still circulates. County L in China has reported measles-containing vaccine (MCV) coverage rates >95% since 2000. Despite high reported coverage, a large measles outbreak occurred among young children in L County. We measured MCV coverage using 5 different methods during an investigation on this outbreak and compared our estimates with reported rates.
  
  
  METHODS
  Reported coverage rates are determined by aggregating clinic-based data across the county: doses administered in each clinic divided by the number of children registered in each clinic. Our methods estimated coverage for the 2010-2012 birth cohort, and were (1) administrative method: doses administered in clinics divided by the birth cohort recorded in the Statistical Year Book, (2) house-to-house convenience-sample survey of children living near cases, (3) vaccination clinic records review, (4) determination of a convenience sample of measles outbreak cases' vaccination statuses and using the field vaccine efficacy outbreak equation to estimate population coverage, and (5) a seroprevalence survey using a convenience sample of residual blood samples from hospitals.
  
  
  RESULTS
  The measles outbreak totaled 215 cases, representing an incidence of 195.8 per million population. Our estimated MCV coverage rates were: (1) administrative method: 84.1%-87.0% for MCV1 and 80.3%-90.0% for MCV2, (2) in-house survey: 83.3% of 9-17 month children received MCV1, and 74.5% of 24-47 month children received MCV2, (3) clinic record review: 85.5% of 9-17 month children received MCV1, and 73.2% of 24-59 month children received MCV2, (4) field VE method: 83.6% of 9-47 month children received one or more MCV doses, and (5) serology: seropositive rates were <80% in the 12-17 and 18-23 month age cohorts.
  
  
  CONCLUSIONS
  Compared with reported coverage >95%, our 5 coverage assessments all showed substantially lower coverage. China should evaluate guidelines for reporting vaccination coverage and identify feasible improvements to the assessment methods.
authors.affiliation: National Immunization Programme, Chinese Center for Disease Control and Prevention, 27 Nanwei Road, Xicheng District, Beijing, China. maachao@163.com.
authors.forename: Chao
authors.initials: C
authors.lastname: Ma
authors.affiliation: Hunan Province Center for Disease Control and Prevention, Changsha, Hu Nan province, China. fangjunliself678@sina.com.
authors.forename: Fangjun
authors.initials: F
authors.lastname: Li
authors.affiliation: Taizhou Prefecture Center for Disease Control and Prevention, Taizhou, Zhe Jiang province, China. xiaoyucool88@163.com.
authors.forename: Xiang
authors.initials: X
authors.lastname: Zheng
authors.affiliation: Hunan Province Center for Disease Control and Prevention, Changsha, Hu Nan province, China. 6184778524@qq.com.
authors.forename: Hong
authors.initials: H
authors.lastname: Zhang
authors.affiliation: National Immunization Programme, Chinese Center for Disease Control and Prevention, 27 Nanwei Road, Xicheng District, Beijing, China. duan123mengjuan@163.com.
authors.forename: Mengjuan
authors.initials: M
authors.lastname: Duan
authors.affiliation: Hunan Province Center for Disease Control and Prevention, Changsha, Hu Nan province, China. hncdcyyh@163.com.
authors.forename: Yanhua
authors.initials: Y
authors.lastname: Yang
authors.affiliation: National Immunization Programme, Chinese Center for Disease Control and Prevention, 27 Nanwei Road, Xicheng District, Beijing, China. lixinh2010@163.com.
authors.forename: Lixin
authors.initials: L
authors.lastname: Hao
authors.affiliation: National Immunization Programme, Chinese Center for Disease Control and Prevention, 27 Nanwei Road, Xicheng District, Beijing, China. shine_firefly@126.com.
authors.forename: Qiru
authors.initials: Q
authors.lastname: Su
authors.affiliation: World Health Organization Office in China, Beijing, China. rodewaldl@wpro.who.int.
authors.forename: Lance
authors.initials: L
authors.lastname: Rodewald
authors.affiliation: Longhui County Center for Disease Control and Prevention, Shaoyang, Hu Nan province, China. 361778524@qq.com.
authors.forename: Bosong
authors.initials: B
authors.lastname: Guo
authors.affiliation: Shaoyang Prefecture Center for Disease Control and Prevention, Shaoyang, Hu Nan province, China. 1178273088@qq.com.
authors.forename: Shanliang
authors.initials: S
authors.lastname: Xiao
authors.affiliation: National Immunization Programme, Chinese Center for Disease Control and Prevention, 27 Nanwei Road, Xicheng District, Beijing, China. hqwang@vip.sina.com.
authors.forename: Huaqing
authors.initials: H
authors.lastname: Wang
authors.affiliation: National Immunization Programme, Chinese Center for Disease Control and Prevention, 27 Nanwei Road, Xicheng District, Beijing, China. llsdjn@163.com.
authors.forename: Li
authors.initials: L
authors.lastname: Li
authors.affiliation: Hunan Province Center for Disease Control and Prevention, Changsha, Hu Nan province, China. 867663530@qq.com.
authors.forename: Junhua
authors.initials: J
authors.lastname: Li
authors.affiliation: National Immunization Programme, Chinese Center for Disease Control and Prevention, 27 Nanwei Road, Xicheng District, Beijing, China. Luohm@Chinacdc.cn.
authors.forename: Huiming
authors.initials: H
authors.lastname: Luo
authors.affiliation: Hunan Province Center for Disease Control and Prevention, Changsha, Hu Nan province, China. gldlj@hotmail.com.
authors.forename: Lidong
authors.initials: L
authors.lastname: Gao
mesh_terms: D000293:Adolescent; D002648:Child; D002662:Child Health Services; D002675:Child, Preschool; D002681:China / Q000453:epidemiology; D004196:Disease Outbreaks / Q000517:prevention & control*; D005260:Female; D006293:Health Promotion; D006801:Humans; D007223:Infant; D008297:Male; D008457:Measles / Q000453:epidemiology* / Q000517:prevention & control; D008458:Measles Vaccine / Q000008:administration & dosage*; D016036:Seroepidemiologic Studies; D014611:Vaccination / Q000706:statistics & numerical data*
chemical_list: D008458:Measles Vaccine