One hundred and twenty-seven (0·3%) reactive serological tests for syphilis were obtained by routine examination of sera from 35,912 antenatal patients.
Forty-eight (38%) of these reactive sera were associated with reactive fluorescent treponemal antibody and Treponema pallidum immobilization results and these patients were therefore considered to show serological evidence of treponemal infection. Sera from 13 of these 48 patients (27%) gave reactive Reiter protein complement-fixation tests in the absence of detected `reagin' antibody. Seventy-nine patients showed non-specific biological false positive reactions to the routine tests.
Following clinical assessment of these serologically reactive patients, approximately one in 100 immigrant and one in 2,500 non-immigrant pregnant women examined in this series were treated with penicillin; this represented just over half the number of patients with serological evidence of a treponemal infection, a ratio which was similar for immigrant and native born women. Yaws was the likely treponemal infection in the majority of infected immigrants. The significance of the serological results and the advantages of the Reiter protein complement-fixation test are discussed.