Biological false positive Wassermann reactions in Uganda.

In a country like Uganda where syphilis is common, yaws occurs, and many of the diseases known to cause false positive Wassermann reactions (such as malaria, leprosy, relapsing fever, smallpox vaccination, trypanosomiasis, lymphogranuloma venereum, and infectious hepatitis) exist, it seemed desirable to obtain some background information about the frequency of positive serological tests for syphilis in the general population in order that the results of tests on individual patients might be evaluated. As the Treponema pallidum immobilization (TPI) test was not available, the validity of the Wassermann reaction (WR) was assessed against the Reiter protein complement-fixation (RPCF) test. Personal experience in Great Britain had shown that the majority of sera giving a positive WR but a negative RPCF test also have a negative TPI test, and a large series of tests has shown the RPCF test to be highly specific (Sequeira 1960). For the purpose of this study a positive WR unsupported by a positive RPCF test is regarded as a biological false positive (BFP) reaction. As was anticipated, BFP reactions occurred with a considerable proportion of sera tested and this paper is mainly concerned with an investigation of the cause of these reactions.