Song-Xing Wang,1,2,* Li-Yan Sun,3,* Qiong Yu,2 Ran Li,4 Yun-Ping Xu,3 Jin-Feng Zeng4 

1Clinical Laboratory, The Third People’s Hospital of Longgang District, Shenzhen, People’s Republic of China; 2Quality Control Department, Shenzhen Blood Center, Shenzhen, People’s Republic of China; 3Institution of Transfusion Medicine, Shenzhen Blood Center, Shenzhen, People’s Republic of China; 4Clinical Laboratory, Shenzhen Blood Center, Shenzhen, People’s Republic of China

*These authors contributed equally to this work

Correspondence: Yun-Ping Xu; Jin-Feng Zeng, Email yunpingxu1982@hotmail.com; zzengjf@163.com

Background: In Shenzhen of China, the continuous increase of syphilis infections threatens the safety of blood transfusion. In 2020, COVID-19 was discovered and spread rapidly around the world, and affected the prevalence of syphilis among blood donors.
Methods: From 2013 to 2020, there were 839,161 blood samples collected in the Shenzhen Blood Center. Blood samples were screened by ELISA tests and confirmed by the TPPA (Treponema pallidum particle agglutination) tests and the TRUST (toluidine red unheated serum tests). All data was analyzed by the chi-square test.
Results: From 2013 to 2020, the positive rate of syphilis among blood donors varied significantly among individuals in different ages, educational backgrounds, regions, and blood donation histories (P< 0.001). In 2020, It was the first time that there were more repeat blood donors than first-time blood donors and more blood donors with a higher education level than those with a lower education level, and the lowest reactive and positive rate of syphilis among blood donors was observed. Compared to 2019, the prevalence of syphilis among female and repeat blood donors decreased significantly in 2020 (P< 0.01).
Conclusion: The prevalence of syphilis in blood donors is related to the characteristics of blood donors (in addition to gender) and the COVID-19 epidemic. COVID-19 can affect the prevalence of syphilis among blood donors by influencing the composition of blood donors and the number of syphile-positive donors in certain blood donors, including female and repeat blood donors.

Keywords: syphilis, COVID-19, blood donors