Sexually transmitted infections (STIs) are transmitted through sexual contact with an infected partner. Firstly, these are classic venereal diseases - syphilis, gonorrhea, chancroid (soft chancre), venereal lymphogranuloma, donovanosis. Secondly, this is a large group of infections accompanied by lesions of the urethra, such as trichomoniasis, urogenital chlamydia, ureamicoplasmosis, urogenital candidiasis, gardnerellosis, genital herpes, urethritis caused by cytomegaloviruses. Also, the group of STIs includes diseases with a primary lesion of other organs and systems, such as HIV infection and viral hepatitis "B" and "C". Sexually transmitted infections are also some skin diseases of infectious and parasitic origin (pubic pediculosis, scabies, genital warts, molluscum contagiosum).