[Analysis on neutralization antibody titer of Japanese B encephalitis virus in healthy population in Shaanxi province].

Objective: To detect Japanese B Encephalitis virus (JEV) neutralization antibody (NA) titer and evaluate immunologic barrier, analyze the factor of affecting JEV NA titer, and provide the data for JE control.

Method: Cluster sampling was selected randomly in the region of high, middle, low JE incidence rate. To detect the NA of JEV by micro neutralization test.

Results: The positive rate of JEV NA (and GMT) was 81.3% (1:27.84) in Ankang prefecture where JE incidence rate was high, 47.9% (1:7.41) in Baoji prefecture where JE incidence rate was middle, 24.1% (1:3.04) in Tongchuan prefecture where JE disease rate was low. There was the tendency that JEV NA titer increased with increasing age in the region of high JE disease rate, and there was not this tendency in the region of low JE incidence rate.

Conclusion: In shaanxi province, the children's JEV NA titer was low in the region of high JE incidence rate, and it is important to vaccinate JE vaccine for children. The adult's JEV NA titer was low in the region of low JE incidence rate. And it is important to control JE disease in adult groups.