Objective: Evaluate GII.4 norovirus infection and blocking effects of serum antibodies against HBGAs binding to GII.4 norovirus of population in oyster culture area, provide references for screening of fully human monoclonal antibody. Methods: Using a random survey method to collect blood and saliva samples in oyster culture area, select serum samples from the inland region of Guangdong as control group. Identification of salivary HBGA receptor phenotype and detection of serum antibody levels between two areas by ELISA. A vitro neutralization model was to determine the efficiency of serum antibodies blocking GII.4 norovirus and HBGA receptors binding. Results: The age were (50.68 ± 15.17), (52.52 ± 15.90) and (51.37 ± 13.32) years old of 2015, 2016 in experimental group, and in control group, respectively. Males accounted for 5.9% (70/195), 36.6%(60/164), 40.8% (69/169) (χ(2)=0.93, P=0.334). The mean value of serum antibodies Absorbance value was 2.521±0.05 of 2015 and was 2.583±0.045 of 2016 in oyster culture area, the mean value was 2.249±0.05 in control group, there was a statistical difference among three group (F=13.28, P<0.001). The antibody prevalence in the three groups was 100%. BT50 geometric mean titer (GMT) of oyster culture area in 2015 was 423.1±40.11, culture group was 248.2±25.63, there was a statistical difference (t=3.73, P<0.001). Conclusion: The population in oyster culture area does have more chance of exposure and infection GII.4 norovirus, Serum antibody of blocking ability in oyster culture areas is better than the general population in inland city. Suggesting that the population is more immunity resistant infected GII.4 norovirus.
目的： 研究广东省某牡蛎养殖区人群血清抗体阻断诺如病毒GII.4与HBGA受体结合的作用。 方法： 分别于2015年1月和2016年12月，采用随机数字表法，以广东省长沙湾牡蛎养殖区为调查点，抽取18岁及以上常住人口为实验组对象，排除具有任何已知的免疫抑制状态或免疫缺陷疾病或正在接受免疫抑制治疗者，以及调查时处于妊娠状态者，2015年1月共抽取调查对象195名，2016年12月共抽取调查对象164名，两次问卷有效回收率均为100%。于2015年11—12月，在匹配年龄、性别条件下，从广东省4个不同内陆地区抽取普通人群为对照组，共169名，问卷有效回收率为100%。采集实验组和对照组对象唾液标本，运用ELISA法对实验组和对照组对象HBGA受体型别进行鉴定，检测调查对象血清抗体水平及其吸光度值，利用诺如病毒体外中和替代模型测定血清抗体阻断诺如病毒GII.4与HBGA受体结合的效率。 结果： 2015年实验组、2016年实验组和对照组对象的年龄分别为（50.68±15.17）、（52.52±15.90）和（51.37±13.32）岁（F=0.21，P=0.650）；男性分别占35.9%（70名）、36.6%（60名）、40.8%（69名）（χ(2)=0.93，P=0.334）。2015年实验组、2016年实验组以及对照组对象血清抗体吸光度值分别为4.202±0.083、4.305±0.075和3.748±0.083（F=13.28，P<0.001）；3组血清抗体阳性率均为100%。2015年实验组对象血清抗体阻断率为50%时，抗体几何平均滴度（GMT）为423.1±40.11，对照组对象血清抗体阻断率为50%时，抗体GMT为248.2±25.63（t=3.73，P<0.001）。 结论： 牡蛎养殖区人群较普通人群有更多的诺如病毒暴露与感染机会，血清抗体阻断能力强，该人群较普通人群对GII.4感染具有更高抵抗能力。.
Keywords: Block; Epidemiology; Norovirus; Serum antibodies.