Background: In 2007, previous syphilis infection was diagnosed in a blood donor who had given blood regularly for 15 years. This was discovered when the donor was tested for syphilis, as a new donor in another blood bank. The time of infection is unknown. An expert group, set up by The Norwegian Directorate of Health, was commissioned to evaluate the risk of syphilis transmission through blood products in Norway.
Material and methods: The expert group based its evaluation on the epidemiology of syphilis, risk of infection and properties of the syphilis bacterium, especially in relation to blood donation. Specific information about the actual incident, made available by the Norwegian Directorate of Health, was also evaluated.
Results: Of 54 blood recipients 21 were alive and 18 (86 %) were tested for syphilis, all with a negative result. For 11 deceased the hospital records were studied without discovering signs of syphilis infection.
Interpretation: The risk of transfusion-transmitted syphilis is low for several reasons: The prevalence of syphilis in the population is low, a compulsory interview and completion of a questionnaire before donation in Norway excludes patients who are ill or at risk of being infected; the proportion of fresh blood donations is very low and syphilis bacteria die quickly during normal storage conditions for blood. An incidental infection is symptomatic and easily treated by antibiotics. The expert group recommends to not start syphilis testing of each blood donor but to continue the present routine testing of new donors.