"Approximately 20 different infections are known to be transmitted through sexual contact. Some of the most common and well-known STDs/STIs include chlamydia, gonorrhea, genital herpes, HIV/AIDS, human papillomavirus (HPV), syphilis, bacterial vaginosis, trichomoniasis, and viral hepatitis. Chlamydia is a common STD/STI caused by the bacterium Chlamydia trachomatis. Chlamydia can be transmitted during vaginal, oral, or anal sexual contact with an infected partner. While many individuals will not experience symptoms, chlamydia can cause fever, abdominal pain, and unusual discharge of the penis or vagina. In women, whether or not they are having symptoms and know about their infection, chlamydia can cause pelvic inflammatory disease (PID). In PID, the untreated STD/STI progresses and involves other parts of the woman’s reproductive system, including the uterus and fallopian tubes. This progression can lead to permanent damage to the woman’s reproductive organs, ectopic pregnancy, and infertility. If a woman is pregnant, chlamydia can be passed on during pregnancy or delivery and could lead to eye infections or pneumonia in the infant. If chlamydia is detected early, it can be treated easily with an antibiotic taken by mouth. Gonorrhea is caused by the bacterium Neisseria gonorrhoeae, which can grow rapidly and multiply easily in the warm, moist areas of the reproductive tract. The most common symptoms of gonorrheal infection are a discharge from the vagina or penis and painful or difficult urination. The most common and serious complications of gonorrhea in women include pelvic inflammatory disease (PID), ectopic pregnancy, infertility, and the potential spread to the developing fetus if acquired during pregnancy. Gonorrhea also can infect the mouth, throat, eyes, and rectum and can spread to the blood and joints, where it can become a life-threatening illness. People with gonorrhea can more easily contract HIV, and HIV-infected people with gonorrhea are also more likely to transmit the virus to someone else."