为掌握山西省长子县O型口蹄疫的免疫抗体水平，评估其免疫效果，2018—2020年在全县14个乡镇的规模场和散养户，随机采集2 258个场户的12 186份血清样品，采用阻断ELISA法检测口蹄疫免疫抗体，并对检测结果进行时间、群间和空间分布分析。结果显示：2018—2020年全县平均场户免疫合格率为81.18%，个体免疫合格率为85.21%。其中：2020年抗体合格率最低，场户和个体免疫合格率分别为70.27%和79.78%，与其他年份差异显著（P＜0.05）；规模场场户合格率和个体免疫合格率分别为87.25%和89.56%，散养户分别为78.96%和82.39%，规模场显著高于散养户（P＜0.05）；王峪、横水2个乡镇免疫效果较好，个体免疫合格率均在90%以上，而大堡头、碾张、色头3个乡镇免疫效果较差，个体免疫合格率为70%~80%，差异显著（P＜0.05）。结果表明：长子县O型口蹄疫整体免疫效果较好，达到了国家要求的70%以上标准；但抗体水平不稳定，且存在一定的地区和场群差异，散养户和部分乡镇免疫水平偏低，存在发生疫情风险。结果提示，长子县可依据地区和场群不均衡的抗体水平分布特点，制定有针对性的免疫措施，分类指导、梯度推进全县口蹄疫防控与净化工作。
In order to identify the immune level of foot-and-mouth disease subtype O（FMD-O）in Zhangzi County of Shanxi Province and to evaluate the immune effects，12 186 serum samples were randomly collected from 2 258 farms/households in 14 townships in the county during 2018 to 2020 to detect antibodies against FMDV by blocking ELISA，then the test results were analyzed based on the distribution of time，intergroup and space. The results showed that the average qualification rate of immunization at farm/household level was 81.18%，and the one at the individual level was 85.21%，specifically，the qualification rates at farm/household and individual level were 70.27% and 79.78% in 2020，respectively，which were lowest and significantly different from those in other years（P＜0.05）；the qualification rates at farm/household and individual level were 87.25% and 89.56% respectively in large-scale farms，and 78.96% and 82.39% in free-range households，respectively，that was，those in large-scale farms were obviously higher than those in free-range households（P＜0.05）；the immune effects were better in Wangyu and Hengshui townships，all individual qualification rates were above 90%，but poorer in Dabaotou，Nianzhang and Setou townships，where the individual rates ranged from 70% to 80% with significant difference（P＜0.05）. In conclusion，the immune effects were generally good in Zhangzi County，which were up to 70% as required；however，the level of antibodies was unstable and different subject to different regions，farms or populations，which was lower in free-range households and some townships，posing a risk of disease occurrence. In conclusion，specific immune measures should be developed in accordance with unbalanced distribution of antibody level to guide to promote the prevention，control and purification of the disease in a gradient way.