摘要目的 了解2011年上海地区不同年龄儿童血清肠道病毒71型(EV71)中和抗体水平.方法 收集2011年7月至8月不同年龄健康儿童血清,采用微量中和试验方法检测儿童血清EV71中和抗体水平.正态分布的计量资料比较采用t检验,计数资料比较采用卡方检验.结果 93份0～8周岁健康儿童血清中,EV71中和抗体阳性率为58.1％(54/93),中和抗体几何平均效价(GMT)为1∶14.48.0～6个月婴儿血清EV71中和抗体阳性率为87.5％(21/24),GMT为1∶29.56;2～3周岁儿童血清EV71中和抗体阳性率为3.7％(1/27),GMT为1∶4.21,均低于0～6个月组婴儿(x2 =36.37,t=7.58;均P＜0.01);5～6周岁儿童血清EV71中和抗体阳性率为83.3％(20/24),GMT为1∶21.74,均高于2～3周岁组(x2=23.90,t=-6.004;均P＜0.01);7～8周岁儿童血清EV71中和抗体阳性率为66.7％(12/18),GMT为1∶20.76,与5～6周岁组间差异均无统计学意义(x2 =1.58,t=0.597;均P＞0.05).男童血清EV71中和抗体阳性率为62.7％(32/51),GMT为1∶16.23;女童血清EV71中和抗体阳性率为52.4％(22/42),GMT为1∶12.61;不同性别儿童血清EV71中和抗体阳性率和GMT比较,差异均无统计学意义(x2=1.02,t=0.881;均P＞0.05).结论 2～3周岁儿童EV71中和抗体水平显著低于0～6个月婴儿和5～8周岁儿童,是EV71感染的高危儿童群体.

abstractsObjective To test the levels of enterovirus 71 (EV71) antibody among children of different ages in Shanghai in 2011,and to investigate the relationship between antibody levels and virus infection.Methods EV71 antibody was detected by microneutralization assay from the serum specimens of healthy children of different ages collected during July to August,2011.The results were analyzed by t test for quantitative data with normal distribution,and by x2 test for count data.Results The positive rate of EV71 antibody among the 93 serum specimens was 58.1％ (54/93).The geometric mean titer (GMT) of EV71-specific neutralizing antibody was 1 ∶ 14.48.The positive rate of EV71 antibody in infants less than 6 months old was 87.5％ (21/24),and the GMT was 1∶29.56.In children aged 2 to 3 years,the positive rate of EV71 antibody decreased to 3.7％ (1/27),and GMT decreased to 1∶4.21,which were both statistically significantly lower than those less than 6 months old (x2 =36.37,t=7.58; both P＜0.01).The positive rate of EV71 antibody increased to 83.3％ (20/24) in children aged 5 to 6 years,with GMT reaching 1∶21.74.Whereas in children aged 7 to 8 years,the positive rate was 66.7％ (12/18) and GMT was 1∶20.76,without statistically significant difference compared with those aged 5 to 6 years (x2 =1.58,t=0.597; both P＞0.05).No statistically significant difference was found between boys and girls in positive rate of EV71 antibody [62.7 ％ (32/51) vs 52.4 ％ (22/42),x2 =1.02,P＞0.05] or GMT (1 ∶ 16.23 vs 1 ∶ 12.61,t=0.881,P＞0.05).Conclusions Children aged 2 to 3 years were at higher risk for EV71 infection,with EV71 antibody level significantly lower than other age groups.