四川省绵阳市1～12岁儿童乙肝表面抗原和乙肝表面抗体的分布现况

目的了解四川省绵阳市1～12岁儿童乙肝表面抗原（HBsAg）和乙肝表面抗体（抗-HBs）的分布现况，为制定和完善儿童乙肝疫苗免疫规划策略提供依据。方法2015年1～12月，采用多阶段分层随机整群抽样方法，抽取绵阳市乙肝计划免疫实施后出生的1～12岁儿童72 623名，对其进行个人信息采集和血标本采集，用ELISA法检测血清HBsAg和抗-HBs，对HBsAg阳性者进行复检。结果绵阳市1～12岁儿童的HBsAg阳性率为0.24%，抗-HBs阳性率为64.50%，HBsAg与抗-HBs双阴性率为35.26%，根据2010年全国第六次人口普查标准化率分别为0.24%、64.05%和35.71%。1～12岁各年龄组儿童的HBsAg阳性率为0%~0.65%，随着年龄增大呈升高趋势（P<0.001），农村儿童HBsAg阳性率（0.32%）高于城市儿童（0.16%，P<0.001），有乙肝家族史儿童HBsAg阳性率（1.53%）高于无家族史儿童（0.22%，P<0.001）；1～12岁各年龄组儿童的抗-HBs阳性率为47.85%~71.43%，随着年龄增大呈降低趋势（P<0.001），农村儿童抗-HBs阳性率（62.06%）低于城市儿童（66.81%，P<0.001）；1～12岁各年龄组儿童HBsAg与抗-HBs双阴性率为28.57%~51.98%，随着年龄增大呈升高趋势（P<0.001）,农村儿童HBsAg与抗-HBs双阴性率（37.62%）高于城市儿童（33.03%，P<0.001），无乙肝免疫史儿童HBsAg与抗-HBs双阴性率为35.37%。结论绵阳市乙肝计划免疫工作取得显著成效，但不同特征儿童抗-HBs阳性率存在差异，乙型肝炎病毒易感儿童仍占一定比例，应重视新生儿乙肝疫苗的接种，积极开展儿童抗-HBs水平监测，对缺乏抗体保护的儿童实施加强免疫。

Prevalence of Hepatitis B Surface Antigens and Hepatitis B Surface Antibodies in 1-12 Years-old Children in Mianyang, Sichuan

Objective To determine the prevalence of hepatitis B surface antigens (HBsAg) and hepatitis B surface antibodies (anti-HBs) in 1-12 years-old children in Mianyang city, Sichuan Province. Methods Children born after the implementation of Hepatitis B immunization policy were selected using a stratified random cluster sampling strategy from January to December 2015. A total of 72 623 eligible children participated in the study, which included a questionnaire survey and blood tests (0.3 mL vein blood) for HBsAg and anti-HBs with ELISA method. Repeated tests were performed on the blood samples with a HBsAg positive result. Results About 0.24% of the children were HBsAg positive; 64.50% were anti-HBs positive; 35.26% were both HBsAg and anti-HBs negative. The standardized rates based on the 2010 population census were: 0.24% HBsAg positive, 64.05% anti-HBs positive, and 35.71% both HBsAg and anti-HBs negative. HBsAg positive rates increased with age, ranging from 0% to 0.65% (P<0.001). Rural children had a higher HBsAg positive rate (0.32%) than their urban counterparts (0.16%, P<0.001). Those with a family history of Hepatitis B had a higher HBsAg positive rate (1.53%) than those without a family history (0.22%, P<0.001). Anti-HBs positive rates decreased withage, ranging from 47.85% to 71.43% (P<0.001). Rural children had a lower anti-HBs positive rate (62.06%)than their urban counterparts (66.81%, P<0.001). The prevalence of both HBsAg and anti-HBs negative cases increased with age, ranging from 28.57% to 51.98% (P<0.001). Rural children had a higher rate of both HBsAg and anti-HBs negative (37.62%) than their urban counterparts (33.03%, P<0.001). About 35.37% of the children who had negative HBsAg and anti-HBs had not received Hepatitis B immunization. Conclusions Hepatitis B vaccinations are highly effective in Mianyang. However, there are disparities in anti-HBs positive rates between the children with different characteristics. A certain proportion of children are still susceptible to hepatitis B infection. It is necessary to attach importance to neonatal hepatitis B vaccination, surveillance on anti-HBs, and strengthened immunization for the children who are lack of antibody protection.