*infections that are commonly transmitted by sexual activity
**oral sex
==Pathogenand disease=====syphilis===*''Treponema pallidum''**one of 3 major spirochaetes - leptospirosis and borrelia*6 mil. new cases/2018*higher in female sex worker and MSM*diagnosis**non-treponemal - positive during active stage; sensitive, not specific***VDRL***RPR**treponemal - positive for lifelong; specific, not sensitive***TPHA***TPPA***FTA {|class="wikitable"!!non-treponemal positive!non-treponemal negative|-!treponemal positive|active syphilis|past syphilis|-!treponemal negative|other active disease|nothing|} *difficulty of microscopy - endemic treponematoses**''T. pallidum'' - Syphilis**''T. ssp pertenue'' - Yaws**''T. pallidum'' spp. ''endemicum'' - Bejel**''T. carateum'' - Pinta*morphologically identical and serologically indistinguishable *maternal syphilis**congenital syphilis***neonatal presentation - poor prognosis***postnatal presentation - fair prognosis*importance of syphilis screening during pregnancy ===genital herpes===*Herpes simplex ===chancroid===*''Haemophilus ducreyi''*Azithromycin ===lymphogranuloma venerum (LGV)===*''Chlamydia trachomatis'' L1,2,3**different serovars from genital chlamydiasis*rare; increasing among MSM in Europe and US ===donovanosis (granuloma inguinale)===*''Krebsiella granulomatis''*India, Papua New Guinea, Brazil, Caribbean*microscopy shows Donovan bodies similar to lieschmania ===''Chlamydia trachomatis'' serovars A, B, Ba, C===*cervicitis and urethritis in females*urethritis in males*neonatal conjunctivitis*classical ocular trachoma*worldwide resistance against azithromycin ===gonorrhea===*''Neisseria gonorrhoea''*microscopic investigation tends to be false-negative in female gonorrhea ===ophthalmia neonatorum===*etiology**gonorrhea**chlamydia**herpes simplex**and more ===human papilloma virus===