Abstract:
Objective To understand the level of measles antibody in population in Dali prefecture of Yunnan province and provide scientific evidence for the elimination of measles. Methods A total of 14 119 persons selected through stratified cluster sampling were surveyed, their blood samples were collected for the detection of measles IgG with enzyme linked immunosorbent assay (ELISA). Results The positive rate of measles antibody and the protective rate were 94.51% and 61.87%. The geometric mean concentration (GMC) was 1 143.78 mIU/ml, and the difference in GMC among different counties were significant (P=0.001).The differences in GMC among difference age groups were also significant (P=0.001). The highest GMC were observed in age group 18-23 months, followed by age group 2-3 years, the immunization coverage rate of measles containing vaccine (MCV) was positively correlated with antibody positive rate and protection rate (P0.05). In population with 2 doses of MCV vaccination, GMC could reach 1 242.31 mIU/ml, compared with those receiving 1 dose vaccination, the difference was significant (P=0.001). Conclusion The herd immunity has been basically formed, so the possibility of measles outbreak or epidemic was lower, but the protection rate was low and varied with county. It is essential to eliminate measles by strengthening the surveillance for measles antibody level in healthy population and finding the weak areas and blank population in immunization.