Sexually transmitted infections (STIs) are diseases passed on from one person to another through unprotected sex (sex without a condom) or sometimes through genital contact. Infections that can be transmitted by sexual contact are a large group of diseases caused by different organisms: bacteria, viruses, parasites, fungi and protozoa. According to current legislation the relevant institutions should be reported in case of following venereal diseases: gonorrhea, syphilis, chlamydia, herpes simplex infection of primary anogenital region, hepatitis and HIV infection.