Detection of antibodies to Neisseria meningitidis serogroup A and C among natural population in Huzhou, Zhejiang and correlation among different indicators, 2012

Objective To understand antibody level to Neisseria meningitidis serogroups A and C among natural population in Huzhou, Zhejiang province and the correlation among different indicators, and provide scientific evidence for the prevention and control of meningococcal meningitis. Methods The serum samples were collected from 635 local healthy subjects selected in 7 age groups through stratified random sampling to conduct the detection of antibodies (IgG) to N. meningitidis serogroup A and C with enzyme-linked immunosorbent assay (ELISA), and the antibody level and related indciators' correlation were analyzed in different groups. Results The positive rate and protective rate of IgG to N. meningitidis serogroup A were 89.92% and 81.89% and the positive rate and protective rate of IgG to serogroup C were 85.20% and 63.76%. The positive correlation was observed among the positive rate, protective rate and antibody level of serogroup A in all age groups. To serogroup C, more decline in protective rate and antibody level were observed than in positive rate in age group 7 years, only the protective rate was positively correlated with the antibody level. The highest protective rate of serogroup A was in age group 7-14 years, while the highest protective rate of serogroup C was in age group 3-4 years. No significant difference in antibody protective rate, protective rate and antibody level were observed between serogroup A and serogroup C in age group 5 years. Conclusion The protective rate of IgG to N. meningitidis serogroup A was high among the natural population in Huzhou. It is necessary to replace serogroups A meningococcal polysaccharide vaccine used in age group 2 years with serogroup A and C meningococcal conjugate vaccine, and serogroups A and C meningococcal conjugate polysaccharide vaccine could be used in age group 2 years.