Sexually transmitted infection

Sexually transmitted infections (STIs), also referred to as sexually transmitted diseases (STDs) and the older term venereal disease, are infections that are spread by sexual activity, especially vaginal intercourse, anal sex and oral sex.[1][5] STIs often do not initially cause symptoms,[1] which results in a risk of passing the infection on to others.[6][7] Symptoms and signs of STIs may include vaginal discharge, penile discharge, ulcers on or around the genitals, and pelvic pain.[1] Some STIs can cause infertility.[1]

Sexually transmitted infection
Other namesSexually transmitted disease (STD);
Venereal disease (VD)
"Syphilis is a dangerous disease, but it can be cured." Poster encouraging treatment. Published between 1936 and 1938.
SpecialtyInfectious disease
SymptomsNone, vaginal discharge, penile discharge, ulcers on or around the genitals, pelvic pain[1]
CausesInfections commonly spread by sex[1]
PreventionNot having sex, vaccinations, condoms[2]
Frequency1.1 billion (STIs other than HIV/AIDS, 2015)[3]
Deaths108,000 (STIs other than HIV/AIDS, 2015)[4]

Bacterial STIs include chlamydia, gonorrhea, and syphilis.[1] Viral STIs include genital herpes, HIV/AIDS, and genital warts.[1] Parasitic STIs include trichomoniasis.[1] STI diagnostic tests are usually easily available in the developed world, but they are often unavailable in the developing world.[1]

Some vaccinations may also decrease the risk of certain infections including hepatitis B and some types of HPV.[2] Safe sex practices, such as use of condoms, having a smaller number of sexual partners, and being in a relationship in which each person only has sex with the other also decreases the risk of STIs.[1][2] Comprehensive sex education may also be useful.[8] Most STIs are treatable and curable; of the most common infections, syphilis, gonorrhea, chlamydia, and trichomoniasis are curable, while HIV/AIDS is not curable.[1]

In 2015, about 1.1 billion people had STIs other than HIV/AIDS.[3] About 500 million were infected with either syphilis, gonorrhea, chlamydia or trichomoniasis.[1] At least an additional 530 million people have genital herpes, and 290 million women have human papillomavirus.[1] STIs other than HIV resulted in 108,000 deaths in 2015.[4] In the United States, there were 19 million new cases of STIs in 2010.[9] Historical documentation of STIs dates back to at least the Ebers papyrus around 1550 BC and the Old Testament.[10] There is often shame and stigma associated with STIs.[1] The term sexually transmitted infection is generally preferred over sexually transmitted disease or venereal disease, as it includes those who do not have symptomatic disease.[11]