Does it Make Sense for Blood Transfusion Services to Continue the Time‐Honored Syphilis Screening with Cardiolipin Antigen?

J.R. Bow. The ultimate result oftestingdonor units should be some clear-cut benefit to either the donor or the recipient. Since all testing will, of necessity, add to the cost of transfusion it is only reasonable that the benefit derived be great enough to justify the cost. In the case of serologic testing for syphilis neither the cost nor the benefit is completely defined, but I believe that existing evidence would not be convincing enough to warrant the de novo addition of such testing. Unfortunately, that is not the issue since testing is already routine, and it is more dificult to eliminate an established pattern than to not start a new one. It seems clear that the original goal of testing to prevent transfusion-transmitted syphilis is no longer important. Spirochetes lose virulence after 4 days of storage at 4'C [I] so that only recipients of fresh blood products are at risk, and in these cases the screening tests are usually negative [2]. Furthermore, most positive tests in donors do not represent syphilis, but are from biologic false-positive reactions which do not represent infected donors. Whether the transfusion of blood from donors with such biologic false-positive reactions is dangerous is unknown but seems highly unlikely. It is quite clear that no one would set about today to institute a test for BFP and eliminate donors with positive results. I, for one, can see no recipient hazard if syphilis testing were to be discontinued. The public health value of syphilis testing is less easy to evaluate. The incidence ofpositive tests is about 2-4/1,000, but fewer than 1/1,000 of these are confirmed as syphilis when tested by more specific tests [3]. Information presented to the BOB Panel on Blood and Blood Products indicated that in 1975 only 154 cases of syphilis (0.6% of the total) were detected by screening some 6-8 million blood donors in the USA. While there are no data on the cost-benefit ratio of such testing, it seems almost axiomatic that it would not be sufficient to institute de novo testing. Thus, I believe that neither public health screening nor recipient protection would be important enough to justify instituting serologic testing were it not already an established procedure. To decide to discontinue such a procedure is less easy. One can argue that blood with a positive test, no matter what the cause, comes from donors who are not completely healthy and, as such, might better be discarded. I prefer to think that the risk, if any, is minimal and that the public interest will be better served by allowing such donations to be used.