天津市武清区健康人群EV71和Cox A16中和抗体阳性状况及影响因素分析

目的 调查天津市武清区健康人群肠道病毒71型（EV71）和柯萨奇病毒A组16 型（Cox A16）中和抗体阳性状况及其影响因素，为手足口病的预防与控制提供依据。方法 采集230名天津市武清区健康人群静脉血标本进行 EV71 和 Cox A16 中和抗体测定，用问卷进行影响因素调查，采用2检验对两种中和抗体阳性影响因素进行分析。结果 以抗体滴度1∶8作为临界值，调查对象EV71中和抗体阳性率为73.91%（170/230），Cox A16中和抗体阳性率为76.52%（176/230），差异无统计学意义（2=0.420，P=0.517）。EV71 与Cox A16中和抗体阳性率最高的年龄组分别为0~岁组、15~岁组（均为76.09%）与0～岁组（84.78%），较低年龄组为5~岁组（71.74%）与15～岁组（69.57%）。不同年份间的EV71中和抗体阳性率差异有统计学意义（2=29.971，P=0.001）。EV71与 Cox A16 中和抗体滴度均以1∶4~ 1∶256居多，分别占82.61%（190/230）和 88.26%（203/230）。经分析发现，EV71 与Cox A16中和抗体阳性的重要影响因素分别为年份、是否外出后洗手与是否为学龄前儿童。结论 人群对EV71和 Cox A16普遍易感，70.00%以上的健康人群感染后均可产生EV71 或 Cox A16的特异性中和抗体，隐匿感染者作为手足口病传染源的意义可能较大。

Survey of neutralizing antibodies against EV71 and Cox A16 in healthy population in Wuqing district,Tianjin

Objective To investigate the latent infection status of enterovirus 71 (EV71) and coxasckievirus A16 (Cox A16) and related factors in healthy population in Wuqing district of Tianjin,and provide evidence for the prevention and control of hand,foot and mouth disease (HFMD).Methods Venous blood samples were collected from 230 healthy people in Wuqing for the detection of neutralizing antibodies against EV71 and Cox A16.The related factors were surveyed by using questionnaire and analyzed withx2 test.Results The antibody titer of 1:8 was used as the critical value,the positive rates of neutralizing antibodies against EV71 and Cox A16 were 73.91％ (170/230) and 76.52％ (176/230) respectively,the difference was not significant (x2 =0.420,P =0.517).The positive rate of neutralizing antibody against EV71 was highest in age groups 0-and 15-years (all 76.09％),while the positive rate of neutralizing antibody against Cox A16 was highest in age group 0-years (84.78％).The lowest positive rates were found in age groups 5-and 15-years respectively (71.74％ and 69.57％).The differences in annual positive rate of neutralizing antibody against EV71 were significant (x2 =29.971,P =0.001).The titers of neutralizing antibodies against EV71 and Cox A16 ranged from 1:4 to 1:256,accounting for 82.61％ (190/230) and 88.26％ (203/230) respectively.The results of x2 test showed that the important influencing factors for the positive detection of neutralizing antibody against EV71 were particular year and habit of washing hands after return from outside;the important influencing factor for the positive detection of neutralizing antibody against Cox A16 was being preschool children.Conclusion People are generally susceptible to EV71 and Cox A16.The infections can produce specific immunity in ＞70.00％ of healthy population.Latent infections might play an important role in the transmission of HFMD.