Sero-epidemiology of measles in general population in Jiangsu province of China: application of mixture models to interpret the results from a cross-sectional study

A cross-sectional survey of measles seroprevalence in general population was conducted in Jiangsu province of China. Data were analyzed by employing commercial ELISA cut-offs and mixture models. The results suggest that the overall measles seroprevalence rate in Jiangsu province (88.7%, 95% confidence interval 87.7-89.6%) was lower than the level believed to be necessary for the elimination of measles. Mixture model could provide a more comprehensive understanding of these results by investigating the different levels of antibody response to vaccination or natural infection in the population, and suggest that the vaccine-induced antibody levels may wane with time. Additional actions should be conducted in the young adult cohorts aged 15-19 years in center region. SIAs for susceptible birth cohorts over the whole province are urgent.