Incubating syphilis in patients treated for gonorrhea: a comparison of treatment regimens

Dade County sexually transmitted disease clinic records were reviewed to estimate the relative effectiveness of gonorrhea treatment regimens for eradicating incubating syphilis. Records were searched to see if persons treated for gonorrhea returned with primary syphilis 3-45 days after treatment or secondary syphilis 15-90 days after treatment. The number of persons treated was adjusted for the prevalence of syphilis in the year of treatment. Between 1985 and 1992, 98,441 persons were treated for gonorrhea. Syphilis was diagnosed in an interval that suggested it was incubating at the time of the treatment for 5.6/10(4) (adjusted number) persons treated with spectinomycin alone (a regimen not expected to eradicate syphilis); 2.9/10(4) persons treated with spectinomycin plus tetracycline, doxycycline, or erythromycin; and 2.1/10(4) persons treated with ceftriaxone plus tetracycline, doxycycline, or erythromycin (P > .1). Incubating syphilis was rare despite a syphilis epidemic. The effectiveness of a regimen for eradicating incubating syphilis should not be a major consideration when choosing gonorrhea therapy.