Epidemiology of measles and surveillance for measles antibody level in healthy population in Xiangyun, Yunnan

Objective To understand the epidemiological characteristics of measles and measles antibody level in healthy population in Xiangyun, Yunnan province. Methods Epidemiological analysis was conducted on the incidence data of measles in Xiangyuan from 2000 to 2012 and blood samples were taken from measles cases and healthy people to detected IgM and IgG antibodies to measles virus with ELISA. Results A total of 58 measles cases were reported during this period, and the annual average incidence was 0.98/lakh (0-3.1/lakh). The disease mainly occurred in Xiangcheng, Midian and Xiazhuang. The cases were reported in all seasons with the peak in spring. The cases in age groups 8 months and 20 years accounted for 63.79% of total cases. The positive rate of IgG was 93.15% in healthy people, but 77.94% in age group 8 months, 91.41% in age group 8-17 months, 92.65% in age group 18 months-5 years, 92.98% in age group 6-9 years, 95.13% in age group 10-14 years, 97.30% in age group 15-19 years and 97.21% in age group 20 year. The protective rate of antibody to measles virus were 71.05% in healthy people, but 9.09% in age group 8 months, 64.63% in age group 8-17 months, 85.92% in age group 18 months-5 years, 79.23% in age group 6-9 years, 74.60% in age group 10-14 years, 80.82% in age group 15-19 years and 61.33% in age group 20 years. Conclusion Infants aged 8 month and adult aged 20 years were affected mostly. Both the measles antibody positive rate and protective antibody level were low in these two age groups. To eliminate measles, it is necessary to strengthen measles vaccination in infants and adults.