Seroprevalence of measles antibodies by region, sex, and age group in the Jiangsu province, 2008–2010 (%).

Abbreviations: CI, confidence interval. a CMH χ2 test was used to test the trend in seroprevalence over years. The seroprevalence of the following stratifications showed a significantly increasing trend over years: north region, south region, male, female, ≤7 months old, and 8–12 months old. b Pearson's χ2 test was used to detect differences between seroprevalence by region, sex, and age group in each year.