Neutralizing antibody level of Japanese encephalitis virus among healthy population in some areas in Shanxi province and Henan province

Objective To investigate neutralizing antibody level of Japanese encephalitis virus among healthy people in some areas in Shanxi province and Henan province. Methods Serum samples collected were diluted by 1 ∶ 10, 1 ∶ 20, 1 ∶ 40, 1 ∶ 80 to conduct neutralization test. The result interpretation will rely on both the cytopathic effect and the ELISA results. Results The results indicated that the neutralizing antibody protection rate in Linyi county (87.6%) was the highest, followed by Luanchun county (58.2%) and Wanrong county (51.4%). By chi-square test, the difference on neutralizing antibody protection rate between Linyi county and Wanrong county had statistically significance (2=42.812, P=0.000), while there was no statistically significant difference (2=1.466, P=0.226) between Luanchuan county and Wanrong county. There was statistically significant difference of neutralizing antibody protection rate between age group more than 40 years and age group less than 40 years in Wanrong county (2=5.505,P=0.019), but no statistically significant differences were observed in Linyi county and Luanchuan county (2=0.057, P=0.811; 2=2.129, P=0.145). Conclusion The neutralizing antibody protection rate varied in 3 counties, which might relate with the local Japanese encephalitis prevalence and vaccination coverage.