A Sexually Transmitted Infection (STI) is an infection which has been transmitted through sexual activity. Some well known examples of STIs are syphilis, AIDS, herpes, and gonorrhea. Doctors prefer the use of the term “STI” rather than Sexually Transmitted Disease (STD), because it is possible for someone to be infected without showing signs of disease, which means that the infection can be passed along by people who are asymptomatic. STIs are a serious issue in many parts of the world since they can be difficult to prevent and treat without access to the proper materials.
Humans have been aware that some diseases appear to be transmitted through sexual activity for hundreds of years. One of the earliest identified STIs was syphilis, a disease which once ravaged European society. They were also known as venereal diseases, after Venus, the Roman goddess of love, or “social diseases.” By the mid 20th century, humans were aware of a laundry list of these diseases, many of which became curable with the advent of penicillin. Towards the end of the 20th century, however, diseases like AIDS emerged, along with drug resistant forms of older Sexually Transmitted Infections, challenging doctors to come up with new treatments for these pernicious infections.
An STI may be fungal, viral, bacterial, or parasitic. Many infections can also be passed through non-sexual contact, leading some medical professionals to call them Sexually Transmissible Infections, to remind people there are numerous vectors for disease transmission, such as needlestick injuries and improper hygiene, among others. Generally, an STI is passed through direct body fluid contact, which means that the risk of contracting one of these diseases can be greatly reduced with the use of barriers during sexual contact. For this reason, many health educators encourage the use of condoms and dental dams.
Once infected, there are varying treatment options, depending on the type of infection. In some cases, antibiotics or antivirals can be used to treat it, knocking it out of the patient's body with the assistance of the immune system. In other cases, as with AIDS or herpes, there is no cure, although drugs may be used to treat the symptoms or to reduce the patient's viral load.
In the developing world, sexually transmitted infections are a major issue, because preventative tools like condoms are either unavailable or socially unacceptable. Treatment can be difficult once someone has been infected because the right drugs may not be available, or the patient may be unable to comply with a drug regimen which requires multiple treatments. Some scientists have raised concerns that partially completed treatments and widespread infection rates may be creating new versions of STIs which could prove difficult to treat in the future.