[Comparative analysis of seroepidemiological survey results of hepatitis B among people aged 1-69 years in Tibet Autonomous Region in 2014 and 2020].

Objective: To evaluate the effectiveness of hepatitis B prevention and control in Tibet Autonomous Region by comparative analysis of the results of seroepidemiological surveys of hepatitis B in 2014 and 2020. Methods: The required sample size was calculated based on the estimated HBsAg positivity rates of permanent residents aged 1-4, 5-14, 15-29, and 30-69 years. A total of 7 163 people and 4 802 people were required in 2014 and 2020, respectively. The subjects were selected by stratified multistage cluster random sampling method, using questionnaires to obtain basic information, and 5 ml of venous blood was collected from each subject to detect HBsAg, anti-HBs, and anti-HBc, and rechecked the HBsAg positive samples. SPSS 22.0 software was used to analyze the survey results, calculate the positive rate and 95% confidence interval. Results: A total of 7 069 people were investigated in 2014 and 4 913 people in 2020. In 2020, the positive rate of HBsAg, anti-HBs, and anti-HBc was 9.20% (452/4 913), 37.11% (1 823/4 913), and 32.75% (1 609/4 913), respectively, and decreased by 22.95%, 15.54%, and 1.92% as compared with the rate in 2014. The positive rate of HBsAg of people aged 1-, 5-, 15- and 30-69 years in 2020 was 2.23% (8/358), 2.85% (20/701), 6.86% (69/1 006) and 12.46%(355/2 848), respectively, decreased by 61.82%, 62.75%, 54.81% and 24.21% as compared with the rate in 2014. The positive rate of anti-HBs of people aged 1-4 years was 52.79% (189/358), 10.30% increased compared with 2014; for people aged 5-, 15-, and 30-69 years was 32.67% (229/701), 37.67% (379/1 006) and 36.03%(1 026/2 848), respectively, decreased by 20.84%, 14.13% and 16.52% as compared with the rate in 2014. The positive rate of anti-HBc of people aged 1-, 5-, 15-, 30-69 years was 4.19% (15/358), 6.42%(45/701), 21.07% (212/1 006), and 46.95% (1 337/2 848), respectively, decreased by 59.63%, 58.93%, 50.49%, and 12.10% as compared with the rate in 2014. Conclusions: The prevention and control of hepatitis B in Tibet have made partial achievements. The prevalence of HBsAg among people aged 1-69 years in 2020 had declined compared with 2014, but it is still at a high epidemic level. People have a high risk of HBV infection for a low level of anti-HBs. It is necessary to strengthen the vaccination of hepatitis B further and effectively implement the strategy of blocking mothers and children of the hepatitis B virus.目的： 对比2014年和2020年西藏自治区（西藏）两次乙型肝炎（乙肝）血清流行病学调查结果，评价西藏乙肝防控效果。 方法： 两次调查均以1~、5~、15~、30~69岁常住人口HBsAg阳性率估计值计算所需样本量，2014年和2020年所需样本量分别为7 163和4 802人。采用多阶段分层整群随机抽样方法抽取调查对象，开展问卷调查并对每名调查对象采集5 ml静脉血，检测HBsAg、抗-HBs、抗-HBc，对HBsAg阳性标本进行复核。使用SPSS 22.0软件对调查结果进行分析，计算各指标阳性率及其95%CI。 结果： 2014年共调查7 069人，2020年共调查4 913人。2020年HBsAg、抗-HBs和抗-HBc阳性率分别为9.20%（452/4 913）、37.11%（1 823/4 913）和32.75%（1 609/4 913），较2014年分别下降22.95%、15.54%、1.92%。1~、5~、15~、30~69岁人群HBsAg阳性率分别为2.23%（8/358）、2.85%（20/701）、6.86%（69/1 006）和12.46%（355/2 848），较2014年分别下降61.82%、62.75%、54.81%和24.21%。1~4岁人群抗-HBs阳性率为52.79%（189/358），较2014年上升10.30%，5~、15~和30~69岁人群分别为32.67%（229/701）、37.67%（379/1 006）、36.03%（1 026/2 848），较2014年分别下降20.84%、14.13%和16.52%。1~、5~、15~、30~69岁人群抗-HBc阳性率分别为4.19%（15/358）、6.42%（45/701）、21.07%（212/1 006）、46.95%（1 337/2 848），较2014年分别下降59.63%、58.93%、50.49%、12.10%。 结论： 西藏乙肝防控工作取得一定成效，1~69岁人群HBsAg阳性率2020年较2014年有所下降，但现阶段仍处于高流行水平。1~69岁人群抗-HBs水平较低，HBV感染风险较大，需进一步加强乙肝疫苗接种工作，有效落实HBV母婴阻断策略。.