Measles antibody level in healthy population in Dali Bai autonomous prefecture, Yunnan, 2012–2018

ObjectiveTo understand the measles antibody level in healthy population in Dali Bai autonomous prefecture of Yunnan province during 2012−2018 and provide scientific evidence for the elimination of measles.

MethodsBlood samples were collected annually from healthy populations in 8 age groups selected through stratified random sampling, a total of 28 459 blood samples were collected. Serum measles IgG was detected by using enzyme linked immunosorbent assay (ELISA).

ResultsThe differences in annual positive rate of measles IgG in healthy population were significant. The positive rate was lowest in 2016 (89.6%) and highest in 2013 (97.3%). The positive rate was ＞90% in other years. The differences in the positive rate were significant among different age groups (P＜0.05). The positive rate was lower in age groups 8−17 months and 25−34 years. There were significant differences in the positive rate and antibody geometric mean concentration (GMC) among people receiving different doses of measles containing vaccine (P＜0.05). The GMC was highest in people receiving 3 doses of measles vaccination (1 921.1 mIU/ml).

ConclusionThe immunity barrier has been basically formed in Dali, the possibility of measles outbreak is low, but close attention should be paid to the potential risk of measles in adults. It is necessary to conduct supplementary immunization activity in order to increase population antibody level and reduce the incidence of measles.