SyphilisSex WorkersPrevalenceSyphilis, CongenitalGonorrheaSyphilis SerodiagnosisHomosexuality, MaleHIV InfectionsChinaSyphilis, CutaneousTreponema pallidumSyphilis, LatentPharyngeal DiseasesPenicillin G ProcaineUrethral DiseasesSexually Transmitted DiseasesNeurosyphilisUrethritisChlamydia InfectionsReaginsSyphilis, CardiovascularRectal DiseasesSpectinomycinProbenecidParaphiliasPregnancy Complications, InfectiousVenereologyHomosexualityProstitutionSexual BehaviorRisk FactorsCross-Sectional StudiesYawsUrethraPenicillinaseSexually Transmitted Diseases, BacterialSexual PartnersAntitreponemal AgentsContact TracingMass ScreeningHeterosexualityChancreCefiximeGenital Diseases, MaleGenital Diseases, FemaleIncidenceTrichomonas VaginitisVaginal DischargeLondonPenicillin GAmpicillinAntibodies, BacterialPelvic Inflammatory DiseasePenicillinsScabiesHemagglutination TestsPregnancyAnus DiseasesUterine CervicitisAge FactorsCeftriaxone