Abstract: ObjectiveTo determine the infection status and immunity level of epidemic cerebrospinal meningitis in susceptible population in Hefei based on immunoserological surveillance.MethodsThe retrospective diagnostic approach was employed to analyze epidemic cerebrospinal meningitis (ECM) infection in susceptible population using ELISA based on the serum samples at the acute phase and convalescent period. The antibody concentration at the acute phase was used to study the immunity level in susceptible population. ResultsA total of 186 ECM cases were detected during the prevalent seasons from 2005 to 2008. The detection rate of group C was 72.6% (135). The antibody concentration of group C Neisseria meningitis at the acute phase was greater than 2 g/ml. The surveillance group consisting of 29 cases contained one positive case with the positive rate of 3.4% (1/29). Conclusion Group C Neisseria meningitis constituted the predominant pathogens in ECM cases in the surveillance in Hefei. Significant protection was signaled in susceptible population when the antibody concentration was greater than 2 g/ml at the acute phase.