Syphilis in blood donors from Tatarstan and Japan

We determined the frequency of donor rejection due to the detection of syphilis markers in blood donors of the Republic of Tatarstan (RT) and compared the results with the data of Japanese colleagues. We studied the results of the examination of donors of the Republican Blood Center (Kazan) in 2015–2024 and the incidence of syphilis in the RT in 2015-2024. In Japan, the quantitative indicators of donation differ from those in the RT: a) the proportion of female donors is 4.6% higher, b) the proportion of repeat donors is 7.2% higher (p<0.001). The incidence of syphilis per 100 thousand blood donations in the RT is 10.9 times higher than in Japan. At the same time, in the RT, repeat donors are rejected 24.7% less often due to laboratory markers of syphilis (p<0.001). During the observation period, the average annual incidence of syphilis in the RT was 13.8 cases per 100,000 population, which is 7 times lower than the syphilis detection rate per 100,000 donations. While the incidence rate in the population has been steadily declining since 2015, among donors this indicator increased sharply in 2018–2020 (151%, 153%, and 122%, respectively). Donors are rejected after a positive laboratory test result, which is not a clinical diagnosis of syphilis and does not exclude the possibility of a false positive result. It is concluded that the high level of positive results of laboratory markers of syphilis in donors (mainly primary) of blood in the RT encourages an active fight against syphilis in the population as a whole, an increase in the specificity of laboratory tests, and infection safety measures for blood transfusion therapy.