A sexually transmitted disease (STD), also known as a sexually transmitted infection (STI) or venereal disease, is a type of infection or illness that is contracted via intimate contact with other individuals. Usually, STDs are transmitted through body fluids, although some blood borne diseases are classified as STDs as well, depending on how easily they can be transmitted to another party. Some STDs are also transmissible through shared drug paraphernalia such as needles. Examples of well-known STDs include gonorrhea, syphilis, Acquired Immunodeficiency Syndrome (AIDS), and herpes. With the regular and correct use of barriers such as condoms, gloves, and dental dams during sexual activity, the risk of transmission can be greatly avoided.
In many cases, an STD can cause serious harm, ranging from damage to the reproductive system to death if left untreated. Many severe STDs have no cure, although medications can be taken to treat symptoms. In other cases, an STD is merely uncomfortable or embarrassing, and can be treated with full spectrum antibiotics. Because some STDs exist in a latent state with no visible symptoms, regular STD screening is highly recommended, along with treatment, if necessary.
An STD can be caused by any one of a number of organisms, including bacteria, viruses, protozoa, and ectoparasites. Viruses such as the human papilloma virus (HPV), cytomegalovirus, and herpes are the most stubborn to treat, as they mutate rapidly and adapt to a wide variety of environments. Ectoparasites and protozoa like pubic lice, giardia, and cryptosporidium are inconvenient, but relatively easy to treat with an assortment of medications. Bacterial infections such as colonization by chlamydia and mycoplasma can also be treated with topical and oral medications.
In most cases, an STD can be passed through contact with body fluids such as mucus, semen, and blood. In some instances, such as ectoparasitic infection, genital contact with an infected individual will result in infection, even if not body fluids are exchanged. Women tend to be at a greater risk of contracting an STD than men, and receivers of anal sex are at a very high risk of transmission.
To avoid getting an STD, most sexual health advocates recommend that condoms and other barriers be used at all times. High risk vectors of disease transmission such as direct blood to blood contact, unprotected penetration, and shared intravenous needles should be avoided at all times. A number of barrier products are available to suit the needs of individuals with latex allergies and other issues, and when the product directions are followed, the risk of transmission is very low. People should also talk with new sexual partners about their disease status, and make sure to be tested regularly, even if they have no symptoms, to ensure that they are not unwittingly passing infection on to a partner.