Hi and thanks for reaching out to us.
Although syphilis is primarily transmitted through person-to-person sexual contact, it may be transmitted by the transfusion of blood and blood components donated by asymptomatic donors who could be having the infection.
The Canadian Blood Services advises donors with a sexually transmitted infection to defer their donations. Deferral periods vary for different sexually transmitted infections. You may be eligible if it has been more than 12 months since you completed treatment for syphilis. You can reach out to the Canadian Blood Services for more information about your eligibility by calling 1-888-236-6283.