Abstract: Objective To evaluate the change of HBsAg positive rate in Gamba County in 5 years after the implementation of Health Poverty Alleviation project for hepatitis B.Methods The positive rates of HBsAg were analyzed among the Tibetan farmers that were outpatients received physical examination and were inpatients in Gamba within 2015 and 2020.Results The positive rate of HBsAg among people who underwent physical examination in 2020 was significantly lower than that in 2015 (15.7% vs 20.0%, P=0.007), so was in the population aged less than 20 (1.6% vs 14.3%, P<0.001). The positive rate of HBsAg was 1.1% in children aged 5-14, while children aged 1-4 all showed negative for HBsAg. In addition, the HBsAg positive rates of Tibetan farmers in both outpatient and inpatient in 2020 were significantly lower than those in 2015 (15.0% vs 24.7%, P=0.001; 14.9% vs 26.4%,P=0.001).Conclusion After targeted prevention and treatment of hepatitis B infection under Health Poverty Alleviation project, the HBsAg positive rates of total Tibetan farmers and children population in Gamba County have been significantly decreasing in five years.

Key words: Hepatitis B virus, Hepatitis B surface antigen, HBsAg, Tibetan farmer