Rubella antibody level and immunity strategy among Chinese residents and Burmese entering China in border regions of Yunnan province: a cross-sectional survey

  Objective  To examine rubella antibody level and the effect of immunization among healthy Chinese residents and Burmese entering China in border regions of Yunnan province for providing evidences to rubella prevention and control in the populations.

  Methods  During 2018 in Yunnan province, we conducted a study including questionnaire survey and blood specimen collection. The participants of the study were 891 residents aged elder than 8 months recruited with multistage random sampling in 27 villages/towns of 3 counties in border regions and 981 people recruited among Burmese entering China for seeking medical service at hospitals in the regions with convenient sampling. The collected blood specimens were detected for rubella immunoglobulin G (IgG) antibody with enzyme-linked immunosorbent assay (ELISA). SPSS 21 software was adopted in data process and analysis.

  Results  Between the Chinese residents and the Burmese entering China, there were significant differences in positive rate of rubella antibody (79.35% 95% confidence interval: 72.03%, 84.94% vs. 84.40% 95% confidence interval: 79.98%, 88.97%, χ² = 6.72, P < 0.05) and geometric mean concentration of IgG (31.37 IU/ml vs. 33.00 IU/ml, U = 2.38; P < 0.05) of rubella. The rubella antibody level differed significantly among the Chinese residents of various age groups, with a lower antibody positive rate in the residents aged 3 – 19 years (χ² = 25.91, P < 0.05) and a lower geometric mean concentration of IgG in the residents aged 3 – 29 years (H = 21.96, P < 0.05). For the childbearing women in the Chinese residents, the rubella antibody positive rate was 82.14% and the geometric mean concentration of IgG was 34.30 IU/ml and reversely correlated with the age of the women.

  Conclusion   The blood rubella antibody is at a relatively low level among healthy populations in China-Myanmar border region of Yunnan province, suggesting that there is a risk of rubella epidemic in Chinese residents due to the infected Burmese entering China, especially in the residents aged 3 – 29 years and in the childbearing women.