2018年甘肃省东南部地区健康人群乙型脑炎病毒中和抗体调查

Investigation on the neutralizing antibody against Japanese encephalitis virus in healthy people in Southeast Gansu province in 2018

目的通过调查甘肃省东南部地区健康人群乙型脑炎病毒(Japanese encephalitis virus,JEV)中和抗体水平,评价人群乙型脑炎(Japanese encephalitis,JE)免疫屏障,为制定JE防控策略提供依据。方法2018年在甘肃省东南部4个市(平凉市、庆阳市、陇南市、天水市),选择0~14岁组、15~39岁组、≥40岁组共3个年龄组健康人群,采集血清标本,采用噬斑减少中和试验检测JEV中和抗体。不同组间JEV中和抗体阳性率的比较采用χ^(2)检验。结果共调查1590人,JEV中和抗体总阳性率为28.81%,几何平均滴度(geometric mean titer,GMT)为1:27.09。0~14岁组、15~39岁组、≥40组健康人群的抗体阳性率依次为32.96%、20.32%、30.63%,各年龄组抗体阳性率差异具有统计学意义(χ^(2)=22.29,P<0.001)。平凉市、庆阳市、陇南市、天水市的抗体阳性率分别为29.62%、22.22%、33.00%、30.30%,各市抗体阳性率差异具有统计学意义(χ^(2)=12.39,P=0.006)。结论甘肃省东南部地区健康人群JEV中和抗体阳性率低,存在JE流行风险。

Objective To determine neutralizing antibodies against Japanese encephalitis virus(JEV)among healthy people of Southeast Gansu province,and to evaluate immunologic barrier,and provide the data for Japanese encephalitis(JE)control.Methods Healthy people were divided into the following 3 groups:less than 14 years,15-39 years,and above 40 years in 2018 in four cities(Pingliang city,Qingyang city,Longnan city,Tianshui city)of Southeast Gansu province.Serum samples of the participants were obtained,and JEV antibody was detected by plaque reduction neutralization assays.The JEV neutralizing antibody positive rates among different groups were compared by chi square test.Results A total of 1590 people were investigated.The total positive rate of JEV neutralizing antibody was 28.81%,and the geometric mean titer(GMT)of JEV neutralizing antibody was 1∶27.09.The antibody positive rates of 0-14,15-39 and≥40 years groups were 32.96%,20.32%,30.63%,the difference of antibody positive rates among different age groups was statistically significant(χ^(2)=22.29,P<0.001).The antibody positive rates in Pingliang city,Qingyang city,Longnan city,Tianshui city were 29.62%,22.22%,33.00%,30.30%,the difference of antibody positive rates among cities was statistically significant(χ^(2)=12.39,P=0.006).Conclusions The positive rates of neutralizing antibodies against JEV was low among healthy people in Southeast Gansu province,and there is an epidemic risk of JE.