Biologic False-Positive Reactions for Syphilis Among Narcotic Addicts

PRIOR to 1949, the occurrence of a reactive serologic test for syphilis (STS) in the absence of a history of lesions of the disease had been considered to be of equivocal significance by many investigators. In that year, the specificTreponema pallidumimmobilization (TPI) test was developed by Nelson and Mayer1thus making available an accurate procedure for the differentiation of biologic false-positive (BFP) reactions from those due to infection withT. pallidum. Subsequently, numerous diseases and conditions have been observed to show BFP reactions, including collagen diseases,2pregnancy,3Brucellainfection, and many others. During the past few years, increasing attention has been focused on the problem of narcotic addiction. Concomitant with this interest, it was observed that sera from many patients addicted to narcotics showed reactive STS. This report presents the incidence of BFP reactions among such individuals as measured by the TPI test. Methods