ABSTRACT
Objective@#To investigate the immunity to mumps after administrating measles-mumps-rubella vaccine (MMR) among children aged 2-7 years old in Jiangsu province in 2015.@*Methods@#A total of 4 190 healthy children aged 2-7 years old, living in local places for at least 3 months, and having been vaccinated at least 1 dose MMR were recruited to the study from Wujin district of Changzhou city, Gaogang district of Taizhou city and Ganyu district of Lianyungang city by using stratified cluster random sampling method between September and November, 2015. Those who did not accept MMR vaccination, who refused venous blood collection, who had affected mumps according to the memory of parents or teachers and who were diagnosed serious disease by clinical doctors were excluded from study. The self-designed questionnaire was used to collect the general information of the subjects and their MMR immunization history; and 0.5-2.0 ml of venous blood was collected from each subject. ELISA was used to detect the mumps antibody level in the serum of patients. Positive was defined as the antibody level ≥108 mU/ml, and negative as <108 mU/ml. χ2 test was used to compare the difference in positive rates among subjects; and analysis of variance was used to compare the GMC changes in different time points after MMR vaccination.@*Results@#Among 4 190 children, 2 280 were males (54.42%) and 1 910 were females(45.58%), and the positive rate of IgG antibody was 81.38% (3 344). There were 3 156 (95.18%) children vaccinated with one dose MMR, 187 (4.80%) children with two dose MMR, and 1 (0.02%) child with three dose MMR. The difference in positive rate of IgG antibody among different aged subjects showed statistical significance (χ2=58.61, P<0.001), the highest positive rate was in group of subjects aged 4-5 years old, at 89.43% (406/454), while the lowest positive rate was found among subjects aged 6-7 years old, at 75.63% (1 648/2 179). The positive rate after one dose of MMR vaccination was 79.14% (3 156/3 988), significantly less than it after two doses (93.03%, 187/201) (χ2=22.93, P<0.001). The GMC level at years<1, 1-<2, 2-<3, 3-<4, ≥4 following one dose MMR in the 3 988 children was 152.47, 227.78, 167.08, 126.91, 79.43 mU/ml, whose difference was statistically significant (F=51.29, P<0.001).@*Conclusion@#The sero-prevalence of IgG antibody in the children aged 2-7 years old in Jiangsu province was high. The positive rate among who received two doses MMR was significantly higher than it among who received just one dose, and the GMC level waned with times.
ABSTRACT
Measles surveillance in Jiangsu Province started in 1999 by dividing the province into two sorts of areas. The first sort of area is economic well-developed area where EPI is carried out well and measles incidence is lower. The cities of this area investigated included Suzhou, Wuxi, Changzhou and Zhenjiang. The second sort of area included 9 cities (Nanjing, Xuzhou, Liangyungang, Nantong, Huaiyin, Suqian, Yangcheng, Yangzhou and Taizhou) where all the conditions are not as good as that mentioned in the first sort of area. The surveillance system of the province reported in 1999 a total of 938 suspected measles cases in 13 cities, of which 684 were confirmed as measles. The notifiable reporting system reported 846 suspected measles cases and 684 cases were confirmed. This indicated that the surveillance system operated well. The measles epidemiological features in two sorts of areas were compared. In first sort of area, including Nanjing, the measles cases of ≥15 years old accounted for 66.3% of the total cases. In second sort of area, not including Nanjing, the measles cases of <15 years old accounted for 90.8% of the total cases, and 73.2% of them were patients <10 years old. In 1999, there were 10 measles outbreaks occurred in the province and 218 measles cases were reported which accounted for 31.7% of the confirmed measles cases reported by the provincial measles surveillance system. 9% the 10 outbreaks occurred in the second sort of area, the cases were preschool and primary school children. The results showed that progression of EPI work was uneven in two sorts of areas of Jiangsu Province.