Seropositivity for syphilis among Brazilian blood donors. A retrospective study 2015-2020

Syphilis is a transfusion-transmitted infection and the disease re-emerged in many countries, including Brazil, as a public health risk.

Evaluate the prevalence of positive serology in blood donations rejected by Hemobanco (Curitiba- PR) from January 2015 to December 2020, with special focus in syphilis.

In the studied period, we analyzed the number of blood donations discarded annually for each serological test performed on blood donors' samples, according to gender and donors age.

Within the studied period, 134,741 blood donation were analyzed. 54.5 % of sample were male. Otherwise, it was observed a significant increase in the number of donations by females (P < 0.0001). There was an increase of 437 % in the prevalence of syphilis positive serology made by donors with ≥ 60 years. Besides that, it was noticed a significant increase in donations by aged people throughout these six years (P < 0.0001). The percentage of total blood donation deferred had a significant reduction, although it was observed an increase in the rate of discarded blood bags due to positive serology in the first 4 studied years. It was observed an increase of 20 % in positive syphilis serology.

The greatest cause of discard of blood donations changed during the analyzed 5-years; there was an increase in seropositivity donations from donors with ≥ 60 years old. In 2015, Hepatitis B (0.8 %) was the most prevalent and in 2020, syphilis became more prevalent (0.82 %). The medical community should be aware of the rising number of cases of syphilis infection. There is an urgent need to implement actions against the dissemination of this disease.