The Clinical Value of the combined Khan and Wassermann Tests in the Tropics, with Special Reference to Yaws and Syphilis

Abstract

1. Sera from 500 patients, mostly natives of East Africa, were tested by the Kahn and Wassermann tests, under conditions described.2. Clinical data were available in the case of 448 specimens. The results of tests upon 230 sera from cases believed to be yaws and syphilis and 218 cases believed not to be yaws and syphilis are discussed. In 46 of the 230 cases, treatment had previously been given.3. In interpreting results, the resolutions of the League of Nations' Conference on the Serodiagnosis of Syphilis were strictly followed.4. In the performance of the tests recognised standard methods were used.5. The two tests correlated exactly in 96·4 per cent. of all cases.6. The Kahn test was the more sensitive to yaws and syphilis.7. The Wassermann test alone gave one non-specific reaction.8. The reagents used in the Kahn test did not deteriorate when kept for two months at room temperature.9. It is suggested that although the use of both tests is preferable when practicable, the Kahn test alone is a reliable diagnostic measure in the tropics.