Abstract: Objective Conducting a Brucella screening test on some unpaid blood donors in the Zhangjiakou area,statistical analysis of test data, confirmatory testing of suspected cases and follow-up visits, to study the risk of suspected Brucella infected individuals participating in blood donation for blood safety and improve blood safety. Methods For the part of the agricultural and pastoral counties in the Zhangjiakou area and non-agricultural and pastoral areas, the Rose Bengal Plate Test was used for the initial screening of Brucella; The positive screening samples are confirmed by tube agglutination test and sent to the local infectious disease hospital laboratory for review; A PCR confirmation test was performed on a specimen of a patient who had been infected with previous disease. Research and analysis were conduct based on all test data and follow-up visit records. Results The survey screened 3 134 blood donors in farming and pastoral areas, and compared with 2 667 blood donors in non-agricultural and pastoral areas, the positive screening rate of agricultural and pastoral areas was 0.35%, and the positive rate was 0.06%, the positive screening rate of non-agricultural and pastoral areas was 0.11%, and the positive rate was 0.04%. A PCR-fluorescent probe test was performed on blood samples from a patient with previous disease who participated in blood donation to confirm positive. Infectious factors were analyzed from data including occupational, exposure and contact history and follow-up treatment of Brucella positive blood donors. Conclusion Brucella-positive people were found in unpaid blood donors in Zhangjiakou area, and there was no statistically significant difference in Brucella infection between unpaid blood donors in pastoral and non-pastoral areas. It is suggested that Brucella infection is no longer unique to pastoral areas but gradually invades the lives of urban residents, and the blood donated by those donors has safety risk. It is important to increase the Brucella consultation and preliminary screening test in the unpaid blood donors in the high-risk area of brucellosis.

Key words: Farming and pastoral areas, Unpaid blood donor, Brucella, Screening analysis