| Objective To understand the level of measles antibodies and the prevalence of measles among healthy population in Dali Prefecture in 2018, evaluate the efficacy of preventive inoculation with measles vaccine, and provide scientific evidence for formulating the prevention and control strategies of measles in Dali prefecture. Methods A stratified cluster sampling method was used to survey 3783 healthy people in Dali Prefecture in 2018. Enzyme-linked immunosorbent assay was used to determine the measles IgG antibody in serum. Descriptive epidemiology method was used to statistically analyze the prevalence of measles and surveillance results of antibody level. Results In 2018, 42 cases of measles were reported in Dali Prefecture, and the incidence rate was 11.91/million. The age of onset was mainly infants under 3 years old and adults in 35-44 years old. There were 25 cases with no or unknown history of vaccination and immunization, accounting for 59.53 % of the total number of reported cases. Their positive rate, protective rate and geometric mean concentration (GMC) of antibodies were the lowest. The positive rate reached the peak after 2 vaccinations. The protective rate and GMC reached the peak after 3 vaccinations; the surveillance results of measles antibody level in healthy population showed that the positive rate, protective rate and GMC of antibodies reached the peak in group of 1-2 years old. The positive rate was the lowest in group of ＜1 year old, and the protective rate and GMC were the lowest in group of 25-34 years old. The differences among age groups were statistically significant (P＜0.05). Conclusions The immune barrier against measles has been basically formed in Dali Prefecture, but the risk of measles is high in infants under 3 years old and adults in 35-44 years old. To strengthen routine immunization, we should adjust the immunization strategy, and carry out leak-detection, catch up immunization among high-risk population and reduce the incidence of the disease. |