I: Certain infectious and parasitic diseases

A50-A64: Infections with a predominantly sexual mode of transmission

Infections with a predominantly sexual mode of transmission, also known as sexually transmitted infections (STIs), are a group of conditions passed from person to person through sexual contact. These conditions are caused by a variety of microorganisms, including bacteria, viruses, and parasites. Common STIs include conditions like syphilis, gonorrhea, chlamydia, or human immunodeficiency virus (HIV). The symptoms of these diseases can vary greatly but often include discomfort in the pelvic area, unusual discharge, sores or blisters in the genital area, and sometimes even flu-like symptoms. Without treatment, STIs can progress and potentially lead to severe health issues, including infertility, certain types of cancer, and systemic complications affecting multiple organs in the body. Transmission can occur through vaginal, anal, or oral sex, and sometimes from mother to baby during childbirth.