Antibody levels to Neisseria meningitidis serogroup A, C, Y and W135 in healthy population in Heifei

Objective To understand the antibody levels to Neisseria meningitidis(Nm)serogroup A, C, Y and W135 in the healthy population in Hefei, monitor the immunization status and incidence trend of the disease as well as discuss the standard of quantitative surveillance. Methods A total of 945 healthy people were selected by stratified random sampling in 7 areas in Hefei and a survey was conducted among them before meningococcal disease season by detecting serogroup A, C, Y and W135 antibodies levels in their serum samples with ELISA. Results In the 945 healthy people, the medians of the antibody concentrations to Nm serogroup A, C, Y and W135 were 12.06, 4.08, 2.36 and 1.25 μg/ml respectively, the geometric mean concentrations(GMC)were 11.75, 4.57, 2.32 and 1.35 μg/ml respectively; the percentile P95 of the antibody concentrations to Nm serogroup Y and W135 were 8.74 and 5.60 μg/ml respectively. The differences on antibody levels in different age groups were significant, The antibody levels to serogroup A and C were highest in age group ≤1 year and lowest in age group 21-30 years; and the antibody levels to serogroup Y and W135 were highest in age group 21-30 years. Conclusion Among the healthy population in Hefei, the antibody level to Nm serogroup A was high, but the antibody levels to Nm serogroup C, Y and W135 were low. It is necessary to standardize the surveillance and specify the quantitative standard of the surveillance to facilitate the nationwide data analysis and comparison.