Sexually transmitted disease

Sexually transmitted diseases (STDs) are infectious diseases transmitted by sexual contact. The agents that cause these diseases include viruses, bacteria, protozoa, and arthropods. Historically, illnesses passed by solely sexual contact were called venereal disease, after Venus, the Roman goddess of love. Venereal diseases generally are infections that require such close contact for transmission that sexual intercourse is one of the only natural ways to catch them. In the pre-antibiotic era, when toxic heavy metal containing compounds were the only effective remedies for the dread venereal disease, syphylis, the standing joke among medical students was " one night on Venus and the rest of your life on Mercury".

More recently, the term sexually transmitted diseases has become popular, and its acronym, the letters STD, is not only an abreviation but the spoken term used most commonly. STDs are the set of infectious diseases that are seen most frequently in promiscuous populations, and although some are transmitted exclusively by sexual contact, others, like Hepatitis B infection and HIV infection, are at least as often spread by other means. Sometimes, the acronym STI, for sexually transmitted infections is used in place of STD. Further adding to the heterogeneity of the conditions described, some clinicians include anything "catching" that can be caught from close physical contact, inlcluding parasites like lice, that are generally thought of as neither an infection or a disease; but as an infestation. Again, this terminology originally arose among health care workers caring for populations of patients that shared these diseases from a combination of sexual contact. intravenous drug abuse, and close physical contact in conditions that were often unsanitary. One problem with the use of this term is that it bears a social stigma, and technically applies to common medical conditions that may occur in virgins who have never abused drugs, and live in the most sanitary of human environments.