Sexually Transmitted Infections

Sexually transmitted infections (STIs), formerly known as sexually transmitted diseases, are among the most common infectious diseases reported worldwide. A variety of bacterial, viral, fungal, and parasitic pathogens can be transmitted through infectious bodily fluids or skin-to-skin contact during sexual contact, including genital, oral, or anal sex. Syphilis, gonorrhea, chlamydia, trichomoniasis, genital herpes, and genital warts are the most common STIs. Less common STIs include chancroid, granuloma inguinale, and lymphogranuloma venereum, designated as tropical STIs because of their restriction mainly to tropical areas. Prevention and control of STIs are based on primary counseling, appropriate diagnostic testing, and effective treatment. This chapter discusses the most common STIs with special reference to clinical manifestations, diagnosis, and treatment.