Sexually transmitted infections (STIs), also referred to as sexually transmitted diseases (STDs) and the older term venereal diseases, are

infection An infection is the invasion of tissues by pathogens, their multiplication, and the reaction of host tissues to the infectious agent and the toxins they produce. An infectious disease, also known as a transmissible disease or communicable dis ...

s that are

spread Spread may refer to: Places * Spread, West Virginia Arts, entertainment, and media * ''Spread'' (film), a 2009 film. * ''$pread'', a quarterly magazine by and for sex workers * "Spread", a song by OutKast from their 2003 album ''Speakerboxxx/T ...

sexual activity Human sexual activity, human sexual practice or human sexual behaviour is the manner in which humans experience and express their sexuality. People engage in a variety of sexual acts, ranging from activities done alone (e.g., masturbation) ...

, especially

vaginal intercourse Sexual intercourse (or coitus or copulation) is a sexual activity typically involving the insertion and thrusting of the penis into the vagina for sexual pleasure or reproduction.Sexual intercourse most commonly means penile–vaginal penetr ...

, anal sex, and

oral sex Oral sex, sometimes referred to as oral intercourse, is sexual activity involving the stimulation of the genitalia of a person by another person using the mouth (including the lips, tongue, or teeth) and the throat. Cunnilingus is oral sex p ...

. STIs often do not initially cause symptoms, which results in a risk of passing the infection on to others. Symptoms and signs of STIs may include

vaginal discharge Vaginal discharge is a mixture of liquid, cells, and bacteria that lubricate and protect the vagina. This mixture is constantly produced by the cells of the vagina and cervix, and it exits the body through the vaginal opening. The composition, amou ...

, penile discharge, ulcers on or around the genitals, and

pelvic pain Pelvic pain is pain in the area of the pelvis. Acute pain is more common than chronic pain. If the pain lasts for more than six months, it is deemed to be chronic pelvic pain. It can affect both the male and female pelvis. Common causes in include ...

. Some STIs can cause infertility. Bacterial STIs include

chlamydia Chlamydia, or more specifically a chlamydia infection, is a sexually transmitted infection caused by the bacterium '' Chlamydia trachomatis''. Most people who are infected have no symptoms. When symptoms do appear they may occur only several we ...

gonorrhea Gonorrhea, colloquially known as the clap, is a sexually transmitted infection (STI) caused by the bacterium ''Neisseria gonorrhoeae''. Infection may involve the genitals, mouth, or rectum. Infected men may experience pain or burning with u ...

, and syphilis. Viral STIs include

genital herpes Genital herpes is an infection by the herpes simplex virus (HSV) of the genitals. Most people either have no or mild symptoms and thus do not know they are infected. When symptoms do occur, they typically include small blisters that break open ...

HIV/AIDS Human immunodeficiency virus infection and acquired immunodeficiency syndrome (HIV/AIDS) is a spectrum of conditions caused by infection with the human immunodeficiency virus (HIV), a retrovirus. Following initial infection an individual ...

, and

genital warts Genital warts are a sexually transmitted infection caused by certain types of human papillomavirus (HPV). They are generally pink in color and project out from the surface of the skin. Usually they cause few symptoms, but can occasionally be pai ...

. Parasitic STIs include

trichomoniasis Trichomoniasis (trich) is an infectious disease caused by the parasite ''Trichomonas vaginalis''. About 70% of affected people do not have symptoms when infected. When symptoms occur, they typically begin 5 to 28 days after exposure. Symptoms ca ...

. STI diagnostic tests are usually easily available in the

developed world A developed country (or industrialized country, high-income country, more economically developed country (MEDC), advanced country) is a sovereign state that has a high quality of life, developed economy and advanced technological infrastruct ...

, but they are often unavailable in the developing world. Some

vaccinations Vaccination is the administration of a vaccine to help the immune system develop immunity from a disease. Vaccines contain a microorganism or virus in a weakened, live or killed state, or proteins or toxins from the organism. In stimulating ...

may also decrease the risk of certain infections including

hepatitis B Hepatitis B is an infectious disease caused by the '' Hepatitis B virus'' (HBV) that affects the liver; it is a type of viral hepatitis. It can cause both acute and chronic infection. Many people have no symptoms during an initial infection. ...

and some types of

HPV Human papillomavirus infection (HPV infection) is caused by a DNA virus from the '' Papillomaviridae'' family. Many HPV infections cause no symptoms and 90% resolve spontaneously within two years. In some cases, an HPV infection persists and re ...

. 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.

Comprehensive sex education Comprehensive sexuality education (CSE) is a sex education instruction method based on-curriculum that aims to give students the knowledge, attitudes, skills, and values to make appropriate and healthy choices in their sexual lives. The intention i ...

may also be useful. Most STIs are treatable and curable; of the most common infections, syphilis, gonorrhea, chlamydia, and trichomoniasis are curable, while HIV/AIDS and genital herpes are not curable. In 2015, about 1.1 billion people had STIs other than HIV/AIDS. About 500 million were infected with either syphilis, gonorrhea, chlamydia or trichomoniasis. At least an additional 530 million people have genital herpes, and 290 million women have

human papillomavirus Human papillomavirus infection (HPV infection) is caused by a DNA virus from the ''Papillomaviridae'' family. Many HPV infections cause no symptoms and 90% resolve spontaneously within two years. In some cases, an HPV infection persists and res ...

. STIs other than HIV resulted in 108,000 deaths in 2015. In the United States, there were 19 million new cases of STIs in 2010. Historical documentation of STIs in antiquity dates back to at least the Ebers Papyrus () and the

Hebrew Bible The Hebrew Bible or Tanakh (;"Tanach"
'' Old Testament (8th/7th centuries BCE). There is often shame and stigma associated with STIs. 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 A disease is a particular abnormal condition that negatively affects the structure or function of all or part of an organism, and that is not immediately due to any external injury. Diseases are often known to be medical conditions that a ...

Signs and symptoms

Not all STIs are symptomatic, and symptoms may not appear immediately after infection. In some instances a disease can be carried with no symptoms, which leaves a greater risk of passing the disease on to others. Depending on the disease, some untreated STIs can lead to infertility,

chronic pain Chronic pain is classified as pain that lasts longer than three to six months. In medicine, the distinction between acute and chronic pain is sometimes determined by the amount of time since onset. Two commonly used markers are pain that continue ...

or death. The presence of an STI in

prepubescent Preadolescence is a stage of human development following middle childhood and preceding adolescence.New Oxford American Dictionary. 2nd Edition. 2005. Oxford University Press. It commonly ends with the beginning of puberty. Preadolescence is ...

children may indicate

sexual abuse Sexual abuse or sex abuse, also referred to as molestation, is abusive sexual behavior by one person upon another. It is often perpetrated using force or by taking advantage of another. Molestation often refers to an instance of sexual assa ...

Cause

Transmission

A sexually transmitted infection present in a pregnant woman may be passed on to the infant before or after birth.

Bacterial

* Chancroid (''

Haemophilus ducreyi ''Haemophilus ducreyi'' is a fastidious gram-negative coccobacillus bacteria. It causes the sexually transmitted disease chancroid, a major cause of genital ulceration in developing countries characterized by painful sores on the genitalia. Ch ...

'') *

Chlamydia Chlamydia, or more specifically a chlamydia infection, is a sexually transmitted infection caused by the bacterium '' Chlamydia trachomatis''. Most people who are infected have no symptoms. When symptoms do appear they may occur only several we ...

(''

Chlamydia trachomatis ''Chlamydia trachomatis'' (), commonly known as chlamydia, is a bacterium that causes chlamydia, which can manifest in various ways, including: trachoma, lymphogranuloma venereum, nongonococcal urethritis, cervicitis, salpingitis, pelvic infla ...

'') *

Gonorrhea Gonorrhea, colloquially known as the clap, is a sexually transmitted infection (STI) caused by the bacterium ''Neisseria gonorrhoeae''. Infection may involve the genitals, mouth, or rectum. Infected men may experience pain or burning with u ...

('' Neisseria gonorrhoeae'') *

Granuloma inguinale Granuloma inguinale is a bacterial disease caused by ''Klebsiella granulomatis'' (formerly known as ''Calymmatobacterium granulomatis'') characterized by genital ulcers. It is endemic in many less-developed regions. It is also known as donovano ...

or (''

Klebsiella granulomatis ''Klebsiella granulomatis'' is Gram-negative, rod-shaped bacterium of the genus ''Klebsiella'' known to cause the sexually transmitted disease granuloma inguinale (or donovanosis). It was formerly called ''Calymmatobacterium granulomatis''. It ...

'') * ''

Mycoplasma genitalium ''Mycoplasma genitalium'' (''MG'', commonly known as Mgen) is a sexually transmitted, small and pathogenic bacterium that lives on the mucous epithelial cells of the urinary and genital tracts in humans. Medical reports published in 2007 and 2 ...

'' * ''

Mycoplasma hominis ''Mycoplasma hominis'' is a species of bacteria in the genus ''Mycoplasma''. ''M.hominis'' has the ability to penetrate the interior of human cells. Along with ureaplasmas, mycoplasmas are the smallest free-living organisms known. They have no ...

'' * Syphilis (''

Treponema pallidum ''Treponema pallidum'', formerly known as ''Spirochaeta pallida'', is a spirochaete bacterium with various subspecies that cause the diseases syphilis, bejel (also known as endemic syphilis), and yaws. It is transmitted only among humans. It is ...

'') * Ureaplasma infection

Viral

Viral hepatitis Viral hepatitis is liver inflammation due to a viral infection. It may present in acute form as a recent infection with relatively rapid onset, or in chronic form. The most common causes of viral hepatitis are the five unrelated hepatotropic vi ...

(

hepatitis B virus ''Hepatitis B virus'' (HBV) is a partially double-stranded DNA virus, a species of the genus '' Orthohepadnavirus'' and a member of the '' Hepadnaviridae'' family of viruses. This virus causes the disease hepatitis B. Disease Despite there b ...

)—saliva, venereal fluids.
(Note:

hepatitis A Hepatitis A is an infectious disease of the liver caused by ''Hepatovirus A'' (HAV); it is a type of viral hepatitis. Many cases have few or no symptoms, especially in the young. The time between infection and symptoms, in those who develop them ...

and

hepatitis E Hepatitis E is inflammation of the liver caused by infection with the hepatitis E virus (HEV); it is a type of viral hepatitis. Hepatitis E has mainly a fecal-oral transmission route that is similar to hepatitis A, although the viruses are unrel ...

are transmitted via the fecal-oral route; hepatitis C is rarely sexually transmittable, and the route of transmission of

hepatitis D Hepatitis D is a type of viral hepatitis caused by the hepatitis delta virus (HDV). HDV is one of five known hepatitis viruses: A, B, C, D, and E. HDV is considered to be a satellite (a type of subviral agent) because it can propagate only in ...

(only if infected with B) is uncertain, but may include sexual transmission.) *

Herpes simplex Herpes simplex is a viral infection caused by the herpes simplex virus. Infections are categorized based on the part of the body infected. Oral herpes involves the face or mouth. It may result in small blisters in groups often called col ...

( Herpes simplex virus 1, 2) skin and mucosal, transmissible with or without visible blisters *

HIV The human immunodeficiency viruses (HIV) are two species of ''Lentivirus'' (a subgroup of retrovirus) that infect humans. Over time, they cause acquired immunodeficiency syndrome (AIDS), a condition in which progressive failure of the immune ...

(''Human Immunodeficiency Virus'')—venereal fluids, semen, breast milk, blood *

(''Human Papillomavirus'')—skin and mucosal contact. 'High risk' types of HPV cause almost all cervical cancers, as well as some

anal Anal may refer to: Related to the anus *Related to the anus of animals: ** Anal fin, in fish anatomy ** Anal vein, in insect anatomy ** Anal scale, in reptile anatomy *Related to the human anus: ** Anal sex, a type of sexual activity involving s ...

, penile, and

vulvar cancer Vulvar cancer is a cancer of the vulva, the outer portion of the female genitals. It most commonly affects the labia majora. Less often, the labia minora, clitoris, or vaginal glands are affected. Symptoms include a lump, itchiness, changes in ...

. Some other types of HPV cause

. *

Molluscum contagiosum Molluscum contagiosum (MC), sometimes called water warts, is a viral infection of the skin that results in small raised pink lesions with a dimple in the center. They may become itchy or sore, and occur singularly or in groups. Any area of the sk ...

( molluscum contagiosum virus MCV)—close contact *

Zika virus ''Zika virus'' (ZIKV; pronounced or ) is a member of the virus family ''Flaviviridae''. It is spread by daytime-active '' Aedes'' mosquitoes, such as '' A. aegypti'' and '' A. albopictus''. Its name comes from the Ziika Forest of Uganda, w ...

Parasites

Crab louse The crab louse or pubic louse (''Pthirus pubis'') is an insect that is an obligate ectoparasite of humans, feeding exclusively on blood. The crab louse usually is found in the person's pubic hair. Although the louse cannot jump, it can also liv ...

, colloquially known as "crabs" or "pubic lice" ('' Pthirus pubis''). The infestation and accompanying inflammation is

Pediculosis pubis Pediculosis pubis (also known as "crabs" and "pubic lice") is an infestation by the pubic louse, ''Pthirus pubis'', a wingless insect which feeds on blood and lays its eggs (nits) on mainly pubic hair. Less commonly, hair near the anus, armpi ...

* Scabies (''

Sarcoptes scabiei ''Sarcoptes scabiei'' or the itch mite is a parasitic mite that burrows into skin and causes scabies. The mite is found in all parts of the world. Humans are not the only mammals that can become infected. Other mammals, such as wild and domesti ...

'') *

Trichomoniasis Trichomoniasis (trich) is an infectious disease caused by the parasite ''Trichomonas vaginalis''. About 70% of affected people do not have symptoms when infected. When symptoms occur, they typically begin 5 to 28 days after exposure. Symptoms ca ...

(''

Trichomonas vaginalis ''Trichomonas vaginalis'' is an anaerobic, flagellated protozoan parasite and the causative agent of a sexually transmitted disease called trichomoniasis. It is the most common pathogenic protozoan that infects humans in industrialized countri ...

''), colloquially known as "trich"

Main types

Sexually transmitted infections include: *

is a sexually transmitted infection caused by the bacterium ''

''. In women, symptoms may include abnormal vaginal discharge, burning during urination, and bleeding in between periods, although most women do not experience any symptoms.King, B. (2009). Human Sexuality Today (Sixth ed.). Upper Saddle River: Pearson Education, Inc. Symptoms in men include pain when urinating, and abnormal discharge from their penis. If left untreated in both men and women, chlamydia can infect the urinary tract and potentially lead to pelvic inflammatory disease (PID). PID can cause serious problems during pregnancy and even has the potential to cause infertility. It can cause a woman to have a potentially deadly ectopic pregnancy, in which the egg implants outside of the uterus. However, chlamydia can be cured with antibiotics. * The two most common forms of

herpes Herpes simplex is a viral infection caused by the herpes simplex virus. Infections are categorized based on the part of the body infected. Oral herpes involves the face or mouth. It may result in small blisters in groups often called cold ...

are caused by infection with herpes simplex virus (HSV). HSV-1 is typically acquired orally and causes cold sores, HSV-2 is usually acquired during sexual contact and affects the genitals, however, either strain may affect either site. Some people are asymptomatic or have very mild symptoms. Those that do experience symptoms usually notice them 2 to 20 days after exposure which lasts 2 to 4 weeks. Symptoms can include small fluid-filled blisters, headaches, backaches, itching or tingling sensations in the genital or anal area, pain during urination, flu like symptoms, swollen glands, or fever. Herpes is spread through skin contact with a person infected with the virus. The virus affects the areas where it entered the body. This can occur through kissing, vaginal intercourse, oral sex or anal sex. The virus is most infectious during times when there are visible symptoms, however, those who are asymptomatic can still spread the virus through skin contact. The initial infection and symptoms are usually the most severe because the body does not have any antibodies built up. After the primary attack, one might have recurring attacks that are milder or might not even have future attacks. There is no cure for the disease but there are antiviral medications that treat its symptoms and lower the risk of transmission ( Valtrex). Although HSV-1 is typically the "oral" version of the virus, and HSV-2 is typically the "genital" version of the virus, a person with HSV-1 orally CAN transmit that virus to their partner genitally. The virus, either type, will settle into a nerve bundle either at the top of the spine, producing the "oral" outbreak, or a second nerve bundle at the base of the spine, producing the genital outbreak. * The

(HPV) is the most common STI in the United States. There are more than 40 different strands of HPV and many do not cause any health problems. In 90% of cases, the body's immune system clears the infection naturally within two years. Some cases may not be cleared and can lead to genital warts (bumps around the genitals that can be small or large, raised or flat, or shaped like cauliflower) or cervical cancer and other HPV related cancers. Symptoms might not show up until advanced stages. It is important for women to get pap smears in order to check for and treat cancers. There are also two vaccines available for women (

Cervarix Cervarix is a vaccine against certain types of cancer-causing human papillomavirus (HPV). Cervarix is designed to prevent infection from HPV types 16 and 18, that cause about 70% of cervical cancer cases. These types also cause most HPV-induced ...

and

Gardasil Gardasil is an HPV vaccine for use in the prevention of certain strains of human papillomavirus (HPV). Text was copied from this source which is copyright European Medicines Agency. Reproduction is authorized provided the source is acknowledge ...

) that protect against the types of HPV that cause cervical cancer. HPV can be passed through genital-to-genital contact as well as during oral sex. The infected partner might not have any symptoms. *

is caused by bacterium that lives on moist mucous membranes in the urethra, vagina, rectum, mouth, throat, and eyes. The infection can spread through contact with the penis, vagina, mouth, or anus. Symptoms of gonorrhea usually appear two to five days after contact with an infected partner however, some men might not notice symptoms for up to a month. Symptoms in men include burning and pain while urinating, increased urinary frequency, discharge from the penis (white, green, or yellow in color), red or swollen urethra, swollen or tender testicles, or sore throat. Symptoms in women may include vaginal discharge, burning or itching while urinating, painful sexual intercourse, severe pain in lower abdomen (if infection spreads to fallopian tubes), or fever (if infection spreads to fallopian tubes); however, many women do not show any symptoms. Antibiotic resistant strains of Gonorrhea are a significant concern, but most cases can be cured with existing antibiotics. SyphilistischeZiekten

* Syphilis is an STI caused by a bacterium. Untreated, it can lead to complications and death. Clinical manifestations of syphilis include the ulceration of the uro-genital tract, mouth or rectum; if left untreated the symptoms worsen. In recent years, the prevalence of syphilis has declined in Western Europe, but it has increased in Eastern Europe (former Soviet states). A high incidence of syphilis can be found in places such as

Cameroon Cameroon (; french: Cameroun, ff, Kamerun), officially the Republic of Cameroon (french: République du Cameroun, links=no), is a country in west-central Africa. It is bordered by Nigeria to the west and north; Chad to the northeast; the C ...

Cambodia Cambodia (; also Kampuchea ; km, កម្ពុជា, UNGEGN: ), officially the Kingdom of Cambodia, is a country located in the southern portion of the Indochinese Peninsula in Southeast Asia, spanning an area of , bordered by Thailan ...

, Papua New Guinea. Syphilis infections are increasing in the United States. *

is a common STI that is caused by infection with a protozoan parasite called ''Trichomonas vaginalis''. Trichomoniasis affects both women and men, but symptoms are more common in women. Most patients are treated with an antibiotic called metronidazole, which is very effective. *

(human immunodeficiency virus) damages the body's immune system, which interferes with its ability to fight off disease-causing agents. The virus kills CD4 cells, which are white blood cells that help fight off various infections. HIV is carried in body fluids and is spread by sexual activity. It can also be spread by contact with infected blood, breastfeeding, childbirth, and from mother to child during pregnancy. When HIV is at its most advanced stage, an individual is said to have AIDS (acquired immunodeficiency syndrome). There are different stages of the progression of and HIV infection. The stages include primary infection, asymptomatic infection, symptomatic infection, and AIDS. In the primary infection stage, an individual will have flu-like symptoms (headache, fatigue, fever, muscle aches) for about two weeks. In the asymptomatic stage, symptoms usually disappear, and the patient can remain asymptomatic for years. When HIV progresses to the symptomatic stage, the immune system is weakened and has a low cell count of CD4+

T cells A T cell is a type of lymphocyte. T cells are one of the important white blood cells of the immune system and play a central role in the adaptive immune response. T cells can be distinguished from other lymphocytes by the presence of a T-cell re ...

. When the HIV infection becomes life-threatening, it is called AIDS. People with AIDS fall prey to opportunistic infections and die as a result. When the disease was first discovered in the 1980s, those who had AIDS were not likely to live longer than a few years. There are now antiretroviral drugs (ARVs) available to treat HIV infections. There is no known cure for HIV or AIDS but the drugs help suppress the virus. By suppressing the amount of virus in the body, people can lead longer and healthier lives. Even though their virus levels may be low they can still spread the virus to others.

Viruses in semen

Twenty-seven different viruses have been identified in semen. Information on whether or not transmission occurs or whether the viruses cause disease is uncertain. Some of these microbes are known to be sexually transmitted.

Pathophysiology

Many STIs are (more easily) transmitted through the

mucous membrane A mucous membrane or mucosa is a membrane that lines various cavities in the body of an organism and covers the surface of internal organs. It consists of one or more layers of epithelial cells overlying a layer of loose connective tissue. It i ...

s of the

penis A penis (plural ''penises'' or ''penes'' () is the primary sexual organ that male animals use to inseminate females (or hermaphrodites) during copulation. Such organs occur in many animals, both vertebrate and invertebrate, but males d ...

vulva The vulva (plural: vulvas or vulvae; derived from Latin for wrapper or covering) consists of the external female sex organs. The vulva includes the mons pubis (or mons veneris), labia majora, labia minora, clitoris, vestibular bulbs, vulv ...

, rectum,

urinary tract The urinary system, also known as the urinary tract or renal system, consists of the kidneys, ureters, bladder, and the urethra. The purpose of the urinary system is to eliminate waste from the body, regulate blood volume and blood pressure, c ...

and (less often—depending on type of infection) the mouth,

throat In vertebrate anatomy, the throat is the front part of the neck, internally positioned in front of the vertebrae. It contains the pharynx and larynx. An important section of it is the epiglottis, separating the esophagus from the trachea (windpip ...

, respiratory tract and

eyes Eyes are organs of the visual system. They provide living organisms with vision, the ability to receive and process visual detail, as well as enabling several photo response functions that are independent of vision. Eyes detect light and con ...

. The visible membrane covering the head of the penis is a mucous membrane, though it produces no

mucus Mucus ( ) is a slippery aqueous secretion produced by, and covering, mucous membranes. It is typically produced from cells found in mucous glands, although it may also originate from mixed glands, which contain both serous and mucous cells. It ...

(similar to the

lip The lips are the visible body part at the mouth of many animals, including humans. Lips are soft, movable, and serve as the opening for food intake and in the articulation of sound and speech. Human lips are a tactile sensory organ, and can be ...

s of the mouth). Mucous membranes differ from

skin Skin is the layer of usually soft, flexible outer tissue covering the body of a vertebrate animal, with three main functions: protection, regulation, and sensation. Other animal coverings, such as the arthropod exoskeleton, have different de ...

in that they allow certain pathogens into the body. The amount of contact with infective sources which causes infection varies with each pathogen but in all cases, a disease may result from even light contact from fluid carriers like venereal fluids onto a mucous membrane. Some STIs such as HIV can be transmitted from mother to child either during pregnancy or breastfeeding. Healthcare professionals suggest

safer sex In cryptography, SAFER (Secure And Fast Encryption Routine) is the name of a family of block ciphers designed primarily by James Massey (one of the designers of IDEA) on behalf of Cylink Corporation. The early SAFER K and SAFER SK designs share t ...

, such as the use of condoms, as a reliable way of decreasing the risk of contracting sexually transmitted diseases during sexual activity, but safer sex cannot be considered to provide complete protection from an STI. The transfer of and exposure to bodily fluids, such as

blood transfusion Blood transfusion is the process of transferring blood products into a person's circulation intravenously. Transfusions are used for various medical conditions to replace lost components of the blood. Early transfusions used whole blood, but mo ...

s and other blood products, sharing injection needles, needle-stick injuries (when medical staff are inadvertently jabbed or pricked with needles during medical procedures), sharing

tattoo A tattoo is a form of body modification made by inserting tattoo ink, dyes, and/or pigments, either indelible or temporary, into the dermis layer of the skin to form a design. Tattoo artists create these designs using several tattooing ...

needles, and childbirth are other avenues of transmission. These different means put certain groups, such as medical workers, and

haemophilia Haemophilia, or hemophilia (), is a mostly inherited genetic disorder that impairs the body's ability to make blood clots, a process needed to stop bleeding. This results in people bleeding for a longer time after an injury, easy bruising, ...

cs and drug users, particularly at risk. It is possible to be an asymptomatic carrier of sexually transmitted diseases. In particular, sexually transmitted diseases in women often cause the serious condition of pelvic inflammatory disease.

Diagnosis

Testing may be for a single infection, or consist of a number of tests for a range of STIs, including tests for syphilis,

trichomonas ''Trichomonas'' is a genus of anaerobic excavate parasites of vertebrates. It was first discovered by Alfred François Donné in 1836 when he found these parasites in the pus of a patient suffering from vaginitis, an inflammation of the vagina. ...

, gonorrhea,

hepatitis Hepatitis is inflammation of the liver tissue. Some people or animals with hepatitis have no symptoms, whereas others develop yellow discoloration of the skin and whites of the eyes ( jaundice), poor appetite, vomiting, tiredness, abdominal ...

, and

. No procedure tests for all infectious agents. STI tests may be used for a number of reasons: * as a

diagnostic test A medical test is a medical procedure performed to detect, diagnose, or monitor diseases, disease processes, susceptibility, or to determine a course of treatment. Medical tests such as, physical and visual exams, diagnostic imaging, genetic ...

to determine the cause of symptoms or illness * as a

screening test Screening, in medicine, is a strategy used to look for as-yet-unrecognised conditions or risk markers. This testing can be applied to individuals or to a whole population. The people tested may not exhibit any signs or symptoms of a disease, or t ...

to detect asymptomatic or presymptomatic

s * as a check that prospective sexual partners are free of disease before they engage in sex without

precautions (for example, when starting a long term mutually monogamous sexual relationship, in fluid bonding, or for procreation). * as a check prior to or during pregnancy, to prevent harm to the baby * as a check after birth, to check that the baby has not caught an STI from the mother * to prevent the use of infected donated blood or

organs In biology, an organ is a collection of tissues joined in a structural unit to serve a common function. In the hierarchy of life, an organ lies between tissue and an organ system. Tissues are formed from same type cells to act together in a f ...

* as part of the process of

contact tracing In public health, contact tracing is the process of identifying persons who may have been exposed to an infected person ("contacts") and subsequent collection of further data to assess transmission. By tracing the contacts of infected individua ...

from a known infected individual * as part of mass

epidemiological Epidemiology is the study and analysis of the distribution (who, when, and where), patterns and determinants of health and disease conditions in a defined population. It is a cornerstone of public health, and shapes policy decisions and evidenc ...

surveillance Early identification and treatment results in less chance to spread disease, and for some conditions may improve the outcomes of treatment. There is often a

window period In medicine, the window period for a test designed to detect a specific disease (particularly infectious disease) is the time between first infection and when the test can reliably detect that infection. In antibody-based testing, the window period ...

after initial infection during which an STI test will be negative. During this period, the infection may be transmissible. The duration of this period varies depending on the infection and the test. Diagnosis may also be delayed by reluctance of the infected person to seek a medical professional. One report indicated that people turn to the Internet rather than to a medical professional for information on STIs to a higher degree than for other sexual problems.

Classification

Until the 1990s, STIs were commonly known as ''venereal diseases'', an antiquated euphemism derived from the Latin , being the adjectival form of

Venus Venus is the second planet from the Sun. It is sometimes called Earth's "sister" or "twin" planet as it is almost as large and has a similar composition. As an interior planet to Earth, Venus (like Mercury) appears in Earth's sky never f ...

, the

Roman goddess Roman mythology is the body of myths of ancient Rome as represented in the literature and visual arts of the Romans. One of a wide variety of genres of Roman folklore, ''Roman mythology'' may also refer to the modern study of these representa ...

of love. However, in the post-classical education era the euphemistic effect was entirely lost, and the common abbreviation "VD" held only negative connotations. Other former euphemisms for STIs include "blood diseases" and "social diseases". The present euphemism is in the use of the initials "STI" rather than in the words they represent. The

World Health Organization The World Health Organization (WHO) is a specialized agency of the United Nations responsible for international public health. The WHO Constitution states its main objective as "the attainment by all peoples of the highest possible level of ...

(WHO) has recommended the more inclusive term ''sexually transmitted infection'' since 1999.

Public health Public health is "the science and art of preventing disease, prolonging life and promoting health through the organized efforts and informed choices of society, organizations, public and private, communities and individuals". Analyzing the det ...

officials originally introduced the term ''sexually transmitted infection'', which clinicians are increasingly using alongside the term ''sexually transmitted disease'' in order to distinguish it from the former.

Prevention

Strategies for reducing STI risk include: vaccination, mutual monogamy, reducing the number of sexual partners, and abstinence. Behavioral counseling for all sexually active adolescents and for adults who are at increased risk. Such interactive counseling, which can be resource-intensive, is directed at a person's risk, the situations in which risk occurs, and the use of personalized goal-setting strategies. The most effective way to prevent sexual transmission of STIs is to avoid contact of body parts or fluids which can lead to transfer with an infected partner. Not all sexual activities involve contact:

cybersex Cybersex, also called computer sex, Internet sex, netsex and, colloquially, cyber or cybering, is a virtual sex encounter in which two or more people have long distance sex via electronic video communication (webcams, VR headsets, etc) and other e ...

, phone sex or masturbation from a distance are methods of avoiding contact. Proper use of condoms reduces contact and risk. Although a condom is effective in limiting exposure, some disease transmission may occur even with a condom. Syphilis is a dangerous disease

Both partners can get tested for STIs before initiating sexual contact, or before resuming contact if a partner engaged in contact with someone else. Many infections are not detectable immediately after exposure, so enough time must be allowed between possible exposures and testing for the tests to be accurate. Certain STIs, particularly certain persistent viruses like HPV, may be impossible to detect. Some treatment facilities use in-home test kits and have the person return the test for follow-up. Other facilities strongly encourage that those previously infected return to ensure that the infection has been eliminated. Novel strategies to foster re-testing have been the use of text messaging and email as reminders. These types of reminders are now used in addition to phone calls and letters. After obtaining a sexual history, a healthcare provider can encourage risk reduction by providing prevention counseling. Prevention counseling is most effective if provided in a nonjudgmental and empathetic manner appropriate to the person's culture, language, gender, sexual orientation, age, and developmental level. Prevention counseling for STIs is usually offered to all sexually active adolescents and to all adults who have received a diagnosis, have had an STI in the past year, or have

multiple sex partners Multiple sex partners is the measure and incidence of engaging in sexual activities with two or more people within a specific time period. Sexual activity with MSP can happen simultaneously or serially. MSP includes sexual activity between people o ...

Vaccines

Vaccines are available that protect against some viral STIs, such as

, and some types of

. Vaccination before initiation of sexual contact is advised to assure maximal protection. The development of vaccines to protect against gonorrhea is ongoing.

Condoms

Condoms and

female condom An internal condom (also known as a femidom or female condom) is a barrier device that is used during sexual intercourse as a barrier contraceptive to reduce the probability of pregnancy or a sexually transmitted infection (STI). Meant as an al ...

s only provide protection when used properly as a barrier, and only to and from the area that they cover. Uncovered areas are still susceptible to many STIs. In the case of HIV, sexual transmission routes almost always involve the penis, as HIV cannot spread through unbroken skin; therefore, properly shielding the penis with a properly worn condom from the vagina or anus effectively stops HIV transmission. An infected fluid to broken skin borne direct transmission of HIV would not be considered "sexually transmitted", but can still theoretically occur during sexual contact. This can be avoided simply by not engaging in sexual contact when presenting open, bleeding wounds. Other STIs, even viral infections, can be prevented with the use of latex, polyurethane or polyisoprene condoms as a barrier. Some microorganisms and viruses are small enough to pass through the pores in natural skin condoms but are still too large to pass through latex or synthetic condoms. Proper male condom usage entails: * Not putting the condom on too tight at the tip by leaving room for

ejaculation Ejaculation is the discharge of semen (the ''ejaculate''; normally containing sperm) from the male reproductory tract as a result of an orgasm. It is the final stage and natural objective of male sexual stimulation, and an essential compone ...

. Putting the condom on too tightly can and often does lead to failure. * Wearing a condom too loose can defeat the barrier * Avoiding inverting or spilling a condom once worn, whether it has ejaculate in it or not * If a user attempts to unroll the condom, but realizes they have it on the wrong side, then this condom may not be effective * Being careful with the condom if handling it with long nails * Avoiding the use of oil-based lubricants (or anything with oil in it) with latex condoms, as oil can eat holes into them * Using flavored condoms for oral sex only, as the sugar in the flavoring can lead to yeast infections if used to penetrate In order to best protect oneself and the partner from STIs, the old condom and its contents are to be treated as infectious and properly disposed of. A new condom is used for each act of intercourse, as multiple usages increase the chance of breakage, defeating the effectiveness as a barrier. In the case of female condoms, the device consists of two rings, one in each terminal portion. The larger ring should fit snugly over the cervix and the smaller ring remains outside the vagina, covering the vulva. This system provides some protection of the external genitalia.

Other

The

cap A cap is a flat headgear, usually with a visor. Caps have crowns that fit very close to the head. They made their first appearance as early as 3200 BC. Caps typically have a visor, or no brim at all. They are popular in casual and informal se ...

was developed after the cervical diaphragm. Both cover the cervix and the main difference between the diaphragm and the cap is that the latter must be used only once, using a new one in each sexual act. The diaphragm, however, can be used more than once. These two devices partially protect against STIs (they do not protect against HIV). Researchers had hoped that

nonoxynol-9 Nonoxynol-9, sometimes abbreviated as N-9, is an organic compound that is used as a surfactant. It is a member of the nonoxynol family of nonionic surfactants. N-9 and related compounds are ingredients in various cleaning and cosmetic products ...

, a vaginal microbicide would help decrease STI risk. Trials, however, have found it ineffective and it may put women at a higher risk of HIV infection. There is evidence that vaginal dapivirine probably reduces HIV in women who have sex with men, other types of vaginal microbicides have not demonstrated effectiveness for HIV or STI's. There is little evidence that school-based interventions such as sexual and reproductive health education programmes on contraceptive choices and condoms are effective on improving the sexual and reproductive health of adolescents. Incentive-based programmes may reduce adolescent pregnancy but more data is needed to confirm this.

Screening

Specific age groups, persons who participate in risky sexual behavior, or those have certain health conditions may require screening. The CDC recommends that sexually active women under the age of 25 and those over 25 at risk should be screened for chlamydia and gonorrhea yearly. Appropriate times for screening are during regular pelvic examinations and preconception evaluations. Nucleic acid amplification tests are the recommended method of diagnosis for gonorrhea and chlamydia. This can be done on either urine in both men and women, vaginal or cervical swabs in women, or urethral swabs in men. Screening can be performed: * to assess the presence of infection and prevent tubal infertility in women * during the initial evaluation before infertility treatment * to identify HIV infection * for men who have sex with men * for those who may have been exposed to hepatitis C * for HCV

Management

In the case of rape, the person can be treated prophylacticly with antibiotics. &nbs
STAT!Ref Online Electronic Medical Library
sup> ubscription required/sup> An option for treating partners of patients (

index case The index case or patient zero is the first documented patient in a disease epidemic within a population, or the first documented patient included in an epidemiological study. It can also refer to the first case of a condition or syndrome (not n ...

s) diagnosed with

or gonorrhea is patient-delivered partner therapy, which is the clinical practice of treating the sex partners of index cases by providing prescriptions or medications to the patient to take to his/her partner without the health care provider first examining the partner.Expedited Partner Therapy in the Management of Sexually Transmitted Diseases (2 February 2006)
U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES PUBLIC HEALTH SERVICE. Centers for Disease Control and Prevention National Center for HIV, STD, and TB Prevention

Epidemiology

STDs excluding HIV world map - DALY - WHO2004

STDs excluding HIV world map-Deaths per million persons-WHO2012

In 2008, it was estimated that 500 million people were infected with either syphilis, gonorrhea, chlamydia or trichomoniasis. At least an additional 530 million people have genital herpes and 290 million women have

. STIs other than HIV resulted in 142,000 deaths in 2013. In the United States there were 19 million new cases of sexually transmitted infections in 2010. In 2010, 19 million new cases of sexually transmitted infections occurred in women in the United States. A 2008

CDC The Centers for Disease Control and Prevention (CDC) is the national public health agency of the United States. It is a United States federal agency, under the Department of Health and Human Services, and is headquartered in Atlanta, Georgi ...

study found that 25–40% of U.S. teenage girls has a sexually transmitted disease. Out of a population of almost 295,270,000 people there were 110 million new and existing cases of eight sexually transmitted infections. Over 400,000 sexually transmitted infections were reported in England in 2017, about the same as in 2016, but there were more than 20% increases in confirmed cases of gonorrhoea and syphilis. Since 2008 syphilis cases have risen by 148%, from 2,874 to 7,137, mostly among men who have sex with men. The number of first cases of genital warts in 2017 among girls aged 15–17 years was just 441, 90% less than in 2009 – attributed to the national human papilloma virus immunisation programme. AIDS is among the leading causes of death in present-day Sub-Saharan Africa. HIV/AIDS is transmitted primarily via unprotected sexual intercourse. More than 1.1 million persons are living with HIV/AIDS in the United States, and it disproportionately impacts

African American African Americans (also referred to as Black Americans and Afro-Americans) are an ethnic group consisting of Americans with partial or total ancestry from sub-Saharan Africa. The term "African American" generally denotes descendants of ens ...

Hepatitis B Hepatitis B is an infectious disease caused by the '' Hepatitis B virus'' (HBV) that affects the liver; it is a type of viral hepatitis. It can cause both acute and chronic infection. Many people have no symptoms during an initial infection. ...

is also considered a sexually transmitted disease because it can be spread through sexual contact. The highest rates are found in Asia and Africa and lower rates are in the Americas and Europe. Approximately two billion people worldwide have been infected with the hepatitis B virus.

History

The first well-recorded European outbreak of what is now known as syphilis occurred in 1494 when it broke out among French troops besieging

Naples Naples (; it, Napoli ; nap, Napule ), from grc, Νεάπολις, Neápolis, lit=new city. is the regional capital of Campania and the third-largest city of Italy, after Rome and Milan, with a population of 909,048 within the city's adminis ...

in the

Italian War of 1494–98 Italian(s) may refer to: * Anything of, from, or related to the people of Italy over the centuries ** Italians, an ethnic group or simply a citizen of the Italian Republic or Italian Kingdom ** Italian language, a Romance language *** Regional Ita ...

. The disease may have originated from the Columbian Exchange. From Naples, the disease swept across

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a subcontinent of Eurasia and it is located entirel ...

, killing more than five million people. As

Jared Diamond Jared Mason Diamond (born September 10, 1937) is an American geographer, historian, ornithologist, and author best known for his popular science books '' The Third Chimpanzee'' (1991); ''Guns, Germs, and Steel'' (1997, awarded a Pulitzer Priz ...

describes it, " en syphilis was first definitely recorded in Europe in 1495, its

pustule A skin condition, also known as cutaneous condition, is any medical condition that affects the integumentary system—the organ system that encloses the body and includes skin, nails, and related muscle and glands. The major function of this s ...

s often covered the body from the head to the knees, caused flesh to fall from people's faces, and led to death within a few months," rendering it far more

fatal Fatal may refer to: * ''Fatal'' (album), by Hussein Fatal, 2002 * ''Fatal'' (film), a 2010 French film starring Michaël Youn and Stéphane Rousseau * '' F.A.T.A.L.'', a tabletop role-playing game released in 2003 * Fatal Recordings, a record ...

than it is today. Diamond concludes," 1546, the disease had evolved into the disease with the symptoms so well known to us today." Gonorrhea is recorded at least up to 700 years ago and associated with a district in Paris formerly known as "Le Clapiers". This is where the prostitutes were to be found at that time. Prior to the invention of modern medicines, sexually transmitted diseases were generally incurable, and treatment was limited to treating the symptoms of the disease. The first voluntary hospital for venereal diseases was founded in 1746 at

London Lock Hospital The London Lock Hospital was the first voluntary hospital for venereal disease. It was also the most famous and first of the Lock Hospitals which were developed for the treatment of syphilis following the end of the use of lazar hospitals, as l ...

.Archives in London and the M25 area
AIM25

London Lock Hospital records
/ref> Treatment was not always voluntary: in the second half of the 19th century, the

Contagious Diseases Acts The Contagious Diseases Acts (CD Acts) were originally passed by the Parliament of the United Kingdom in 1864 (27 & 28 Vict. c. 85), with alterations and additions made in 1866 (29 & 30 Vict. c. 35) and 1869 (32 & 33 Vict. c. 96). In 1862, a com ...

were used to arrest suspected prostitutes. In 1924, a number of states concluded the Brussels Agreement, whereby states agreed to provide free or low-cost medical treatment at ports for merchant seamen with venereal diseases. A proponent of these approaches was Dr.

Nora Wattie Nora Wattie (1900–1994) MBChB (Aberdeen), DPH (Cambridge) was a pioneer of social medicine, setting up Glasgow’s internationally renowned ante-natal care service (both before and after the creation of the National Health Service). Throughou ...

, OBE, Venereal Diseases Officer in Glasgow from 1929, encouraged

and volunteering for treatment, rather than the prevailing more judgemental view and published her own research on improving sex education and maternity care. The first effective treatment for a sexually transmitted disease was

salvarsan Arsphenamine, also known as Salvarsan or compound 606, is a drug that was introduced at the beginning of the 1910s as the first effective treatment for syphilis, relapsing fever, and African trypanosomiasis. This organoarsenic compound was the fi ...

, a treatment for syphilis. With the discovery of antibiotics, a large number of sexually transmitted diseases became easily curable, and this, combined with effective public health campaigns against STIs, led to a public perception during the 1960s and 1970s that they have ceased to be a serious medical threat. During this period, the importance of contact tracing in treating STIs was recognized. By tracing the sexual partners of infected individuals, testing them for infection, treating the infected and tracing their contacts, in turn, STI clinics could effectively suppress infections in the general population. In the 1980s, first genital herpes and then AIDS emerged into the public consciousness as sexually transmitted diseases that could not be cured by modern medicine. AIDS, in particular, has a long asymptomatic period—during which time

(the human immunodeficiency virus, which causes AIDS) can replicate and the disease can be transmitted to others—followed by a symptomatic period, which leads rapidly to death unless treated. HIV/AIDS entered the United States from Haiti in about 1969. Recognition that AIDS threatened a global pandemic led to public information campaigns and the development of treatments that allow AIDS to be managed by suppressing the replication of HIV for as long as possible. Contact tracing continues to be an important measure, even when diseases are incurable, as it helps to contain infection.

References

External links

* *
CDC Sexually Transmitted Diseases Treatment Guidelines, 2010

STD photo library
at Dermnet
UNFPA: Breaking the Cycle of Sexually Transmitted Infections
at

UNFPA The United Nations Population Fund (UNFPA), formerly the United Nations Fund for Population Activities, is a UN agency aimed at improving reproductive and maternal health worldwide. Its work includes developing national healthcare strategies ...

STDs In Color: Sexually Transmitted Disease Facts and Photos

Sexually transmitted diseases in the U.S.
STI Watch: World Health Organization
{{authority control Wikipedia medicine articles ready to translate Wikipedia emergency medicine articles ready to translate Mycoplasma Disease transmission

Signs and symptoms

Cause

Transmission

Bacterial

Viral

Parasites

Main types

Viruses in semen

Pathophysiology

Diagnosis

Classification

Prevention

Vaccines

Condoms

Other

Screening

Management

Epidemiology

History

See also

References

Further reading

External links