Sexually transmitted disease
Encyclopedia
Sexually transmitted disease (STD), also known as a sexually transmitted infection (STI) or venereal disease (VD), is an illness that has a significant probability of transmission between human
s by means of human sexual behavior
, including vaginal intercourse
, oral sex
, and anal sex
. While in the past, these illnesses have mostly been referred to as STDs or VD, in recent years the term sexually transmitted infections (STIs) has been preferred, as it has a broader range of meaning; a person may be infected, and may potentially infect others, without having a disease. Some STIs can also be transmitted via the use of IV drug
needle
s after its use by an infected person, as well as through childbirth
or breastfeeding
. Sexually transmitted infections have been well known for hundreds of years.
genitive form of the name Venus
, the Roman goddess
of love. Social disease was another euphemism.
Sexually transmitted infection is a broader term than sexually transmitted disease.
An infection is a colonization by a parasitic species, which may not cause any adverse effects. In a disease the infection leads to impaired or abnormal function. In either case the condition may not exhibit signs or symptoms. Increased understanding of infections like HPV, which infects most sexually active individuals but cause disease in only a few has led to increased use of the term STI. Public health
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.
STD may refer only to infection
s that are causing disease
s, or it may be used more loosely as a synonym for STI. Because most of the time people do not know that they are infected with an STD until they are tested or start showing symptoms of disease
, most people use the term STD, even though the term STI is also appropriate in many cases.
Moreover, the term sexually transmissible disease is sometimes used since it is less restrictive in consideration of other factors or means of transmission. For instance, meningitis
is transmissible by means of sexual contact but is not labeled as an STI because sexual contact is not the primary vector for the pathogen
s that cause meningitis. This discrepancy is addressed by the probability of infection by means other than sexual contact. In general, an STI is an infection that has a negligible probability of transmission by means other than sexual contact, but has a realistic means of transmission by sexual contact (more sophisticated means—blood transfusion
, sharing of hypodermic needle
s—are not taken into account). Thus, one may presume that, if a person is infected with an STI, e.g., chlamydia, gonorrhea
, genital herpes, it was transmitted to him/her by means of sexual contact.
The diseases on this list are most commonly transmitted solely by sexual activity. Many infectious diseases, including the common cold
, influenza
, pneumonia
, and most others that are transmitted person-to-person can also be transmitted during sexual contact, if one person is infected, due to the close contact involved. However, even though these diseases may be transmitted during sex, they are not considered STDs.
s of the penis
, vulva
, rectum
, urinary tract and (less often—depending on type of infection) the mouth
, throat
, respiratory tract
and eyes. The visible membrane covering the head of the penis
is a mucous membrane, though it produces no mucus
(similar to the lip
s of the mouth). Mucous membranes differ from skin
in that they allow certain pathogens into the body. Pathogens are also able to pass through breaks or abrasions of the skin, even minute ones. The shaft of the penis is particularly susceptible due to the friction caused during penetrative sex. The primary sources of infection in ascending order are venereal fluids, saliva, mucosal or skin (particularly the penis), infections may also be transmitted from feces, urine and sweat. 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.
This is one reason that the probability of transmitting many infections is far higher from sex than by more casual means of transmission, such as non-sexual contact—touching, hugging, shaking hands—but it is not the only reason. Although mucous membrane
s exist in the mouth as in the genitals, many STIs seem to be easier to transmit through oral sex
than through deep kissing. According to a safe sex chart, many infections that are easily transmitted from the mouth to the genitals or from the genitals to the mouth, are much harder to transmit from one mouth to another. With HIV
, genital fluids happen to contain much more of the pathogen
than saliva
. Some infections labeled as STIs can be transmitted by direct skin
contact. Herpes simplex
and HPV are both examples. KSHV
, on the other hand, may be transmitted by deep-kissing but also when saliva is used as a sexual lubricant.
Depending on the STD, a person may still be able to spread the infection if no signs of disease are present. For example, a person is much more likely to spread herpes infection when blister
s are present (STD) than when they are absent (STI). However, a person can spread HIV
infection (STI) at any time, even if he/she has not developed symptoms of AIDS
(STD).
All sexual behaviors
that involve contact with the bodily fluids of another person should be considered to contain some risk of transmission of sexually transmitted diseases. Most attention has focused on controlling HIV
, which causes AIDS
, but each STD presents a different situation.
As may be noted from the name, sexually transmitted diseases are transmitted from one person to another by certain sexual activities rather than being actually caused by those sexual activities. Bacteria, fungi, protozoa
or virus
es are still the causative agents. It is not possible to catch any sexually transmitted disease from a sexual activity with a person who is not carrying a disease; conversely, a person who has an STD got it from contact (sexual or otherwise) with someone who had it, or his/her bodily fluids. Some STDs such as HIV can be transmitted from mother to child either during pregnancy or breastfeeding.
Although the likelihood of transmitting various diseases by various sexual activities varies a great deal, in general, all sexual activities between two (or more) people should be considered as being a two-way route for the transmission of STDs, i.e., "giving" or "receiving" are both risky although receiving carries a higher risk.
Healthcare professionals suggest safer sex, such as the use of condoms, as the most reliable way of decreasing the risk of contracting sexually transmitted diseases during sexual activity, but safer sex should by no means be considered an absolute safeguard. The transfer of and exposure to bodily fluids, such as blood transfusion
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
needles, and childbirth are other avenues of transmission. These different means put certain groups, such as medical workers, and haemophilia
cs and drug users, particularly at risk.
Recent epidemiological
studies have investigated the networks that are defined by sexual relationships between individuals, and discovered that the properties of sexual network
s are crucial to the spread of sexually transmitted diseases. In particular, assortative mixing
between people with large numbers of sexual partners seems to be an important factor.
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
.
s fight to promote the use of condoms and provide outreach for at-risk communities.
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
, phonesex or masturbation
from a distance are methods of avoiding contact. Proper use of condom
s reduces contact and risk. Although a condom is effective in limiting exposure, some disease transmission may occur even with a condom.
Ideally, both partners should 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 with current medical procedures.
Many diseases that establish permanent infections can so occupy the immune system that other diseases become more easily transmitted. The innate immune system
led by defensins against HIV can prevent transmission of HIV when viral counts are very low, but if busy with other viruses or overwhelmed, HIV can establish itself. Certain viral STI's also greatly increase the risk of death for HIV infected patients.
, Hepatitis B
, and some types of HPV
. Vaccination before initiation of sexual contact is advised to assure maximal protection.
s and female condom
s only provide protection when used properly as a barrier, and only to and from the area that it covers. Uncovered areas are still susceptible to many STDs. In the case of HIV, sexual transmission routes almost always involve the penis, as HIV cannot spread through unbroken skin, thus properly shielding the insertive 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 having open bleeding wounds. Other STDs, 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 usage entails:
Not following the first five guidelines above perpetuates the common misconception that condoms are not tested or designed properly.
In order to best protect oneself and the partner from STIs, the old condom and its contents should be assumed to be infectious. Therefore the old condom must be properly disposed of. A new condom should be used for each act of intercourse, as multiple usage increases the chance of breakage, defeating the effectiveness as a barrier.
, a vaginal microbicide would help decrease STD rates. Trials, however, have found it ineffective. In fact, the use of nonoxynol-9 can put women at a higher risk of HIV infection.
may test for a single infection, or consist of a number of individual tests for any of a wide range of STIs, including tests for syphilis
, trichomonas
, gonorrhea
, chlamydia, herpes, hepatitis
and HIV test
s. No procedure tests for all infectious agents.
STI tests may be used for a number of reasons:
Not all STIs are symptom
atic, 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
or even death. 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
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 afflicted people turn to the Internet rather than to a medical professional for information on STIs to a higher degree than for other sexual problems.
for determining which screening tests, vaccinations, and evaluations are recommended, related to sexually transmitted diseases. The information included within the STD Wizard is based on the Centers for Disease Control and Prevention
"Sexually Transmitted Diseases Treatment Guidelines - 2006". The system has English and Spanish language interfaces.
The STD Wizard runs in a web browser. The program asks a series of questions, related to demographics, behaviors, and symptoms. There are potentially over 100 questions, but most users get asked about 20. The exact questions asked depend on the user's responses. Typical questions include:
Typical recommendations include:
, cefixime
, and metronidazole
.
An option for treating partners of patients (index cases) diagnosed with chlamydia 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.
(e.g., penicillin-resistant gonococci) makes some STDs harder to cure. The effect of travel is most dramatically illustrated by the rapid spread of the AIDS
virus (HIV-1) from Africa to Europe and the Americas in the late 1970s.
In 1996, the World Health Organization
estimated that more than 1 million people were being infected daily. About 60% of these infections occur in young people <25 years of age, and of these 30% are <20 years. Between the ages of 14 and 19, STDs occur more frequently in girls than boys by a ratio of nearly 2:1; this equalizes by age 20. An estimated 340 million new cases of syphilis, gonorrhea, chlamydia and trichomoniasis occurred throughout the world in 1999.
Commonly reported prevalences of STIs among sexually active adolescent girls both with and without lower genital tract symptoms include chlamydia (10–25%), gonorrhea
(3–18%), syphilis
(0–3%), Trichomonas vaginalis
(8–16%), and herpes simplex virus (2–12%). Among adolescent boys with no symptoms of urethritis, isolation rates include chlamydia (9–11%) and gonorrhea (2–3%).
At least one in four U.S. teenage girls has a sexually transmitted disease, a CDC
study found. Among girls who admitted ever having sex, the rate was 40%.
AIDS
is the single largest cause of mortality in present-day Sub-Saharan Africa
. The majority of HIV
infections are acquired through unprotected sexual relations between partners, one of whom has HIV. Approximately 1.1 million persons are living with HIV/AIDS in the United States
, and AIDS remains the leading cause of death among African American
women between ages 25 and 34. Hepatitis B is also classed as a sexually transmitted disease because it can be passed on sexually. The disease is found globally, with the highest rates in Asia and Africa and lower rates in the Americas and Europe. Worldwide, an estimated two billion people have been infected with the hepatitis B virus.
occurred in 1494 when it broke out among French troops besieging Naples
. From this centre, the disease swept across Europe
, killing more than five million people. As Jared Diamond
describes it, "[W]hen syphilis was first definitely recorded in Europe in 1495, its pustules 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
than it is today. Diamond concludes,"[B]y 1546, the disease had evolved into the disease with the symptoms so well known to us today."
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
. Treatment was not always voluntary: in the second half of the 19th century, the Contagious Diseases Act was used to arrest suspected prostitutes.
The first effective treatment for a sexually transmitted disease was salvarsan
, a treatment for syphilis. With the discovery of antibiotic
s, a large number of sexually transmitted diseases became easily curable, and this, combined with effective public health campaigns against STDs, 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 be very effective at suppressing 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 HIV
(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 in about 1969 likely through a single infected immigrant from Haiti. 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.
Human
Humans are the only living species in the Homo genus...
s by means of human sexual behavior
Human sexual behavior
Human sexual activities or human sexual practices or human sexual behavior refers to the manner in which humans experience and express their sexuality. People engage in a variety of sexual acts from time to time, and for a wide variety of reasons...
, including vaginal intercourse
Sexual intercourse
Sexual intercourse, also known as copulation or coitus, commonly refers to the act in which a male's penis enters a female's vagina for the purposes of sexual pleasure or reproduction. The entities may be of opposite sexes, or they may be hermaphroditic, as is the case with snails...
, oral sex
Oral sex
Oral sex is sexual activity involving the stimulation of the genitalia of a sex partner by the use of the mouth, tongue, teeth or throat. Cunnilingus refers to oral sex performed on females while fellatio refer to oral sex performed on males. Anilingus refers to oral stimulation of a person's anus...
, and anal sex
Anal sex
Anal sex is the sex act in which the penis is inserted into the anus of a sexual partner. The term can also include other sexual acts involving the anus, including pegging, anilingus , fingering, and object insertion.Common misconception describes anal sex as practiced almost exclusively by gay men...
. While in the past, these illnesses have mostly been referred to as STDs or VD, in recent years the term sexually transmitted infections (STIs) has been preferred, as it has a broader range of meaning; a person may be infected, and may potentially infect others, without having a disease. Some STIs can also be transmitted via the use of IV drug
Drug injection
In substance dependence and recreational drug use, drug injection is a method of introducing a drug into the body with a hollow needle and a syringe which is pierced through the skin into the body...
needle
Hypodermic needle
A hypodermic needle is a hollow needle commonly used with a syringe to inject substances into the body or extract fluids from it...
s after its use by an infected person, as well as through childbirth
Childbirth
Childbirth is the culmination of a human pregnancy or gestation period with the birth of one or more newborn infants from a woman's uterus...
or breastfeeding
Breastfeeding
Breastfeeding is the feeding of an infant or young child with breast milk directly from female human breasts rather than from a baby bottle or other container. Babies have a sucking reflex that enables them to suck and swallow milk. It is recommended that mothers breastfeed for six months or...
. Sexually transmitted infections have been well known for hundreds of years.
Classification
Until the 1990s, STDs were commonly known as venereal diseases: Veneris is the LatinLatin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...
genitive form of the name Venus
Venus (mythology)
Venus is a Roman goddess principally associated with love, beauty, sex,sexual seduction and fertility, who played a key role in many Roman religious festivals and myths...
, the Roman goddess
Roman mythology
Roman mythology is the body of traditional stories pertaining to ancient Rome's legendary origins and religious system, as represented in the literature and visual arts of the Romans...
of love. Social disease was another euphemism.
Sexually transmitted infection is a broader term than sexually transmitted disease.
An infection is a colonization by a parasitic species, which may not cause any adverse effects. In a disease the infection leads to impaired or abnormal function. In either case the condition may not exhibit signs or symptoms. Increased understanding of infections like HPV, which infects most sexually active individuals but cause disease in only a few has led to increased use of the term STI. Public health
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" . It is concerned with threats to health based on population health...
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.
STD may refer only to infection
Infection
An infection is the colonization of a host organism by parasite species. Infecting parasites seek to use the host's resources to reproduce, often resulting in disease...
s that are causing disease
Disease
A disease is an abnormal condition affecting the body of an organism. It is often construed to be a medical condition associated with specific symptoms and signs. It may be caused by external factors, such as infectious disease, or it may be caused by internal dysfunctions, such as autoimmune...
s, or it may be used more loosely as a synonym for STI. Because most of the time people do not know that they are infected with an STD until they are tested or start showing symptoms of disease
Disease
A disease is an abnormal condition affecting the body of an organism. It is often construed to be a medical condition associated with specific symptoms and signs. It may be caused by external factors, such as infectious disease, or it may be caused by internal dysfunctions, such as autoimmune...
, most people use the term STD, even though the term STI is also appropriate in many cases.
Moreover, the term sexually transmissible disease is sometimes used since it is less restrictive in consideration of other factors or means of transmission. For instance, meningitis
Meningitis
Meningitis is inflammation of the protective membranes covering the brain and spinal cord, known collectively as the meninges. The inflammation may be caused by infection with viruses, bacteria, or other microorganisms, and less commonly by certain drugs...
is transmissible by means of sexual contact but is not labeled as an STI because sexual contact is not the primary vector for the pathogen
Pathogen
A pathogen gignomai "I give birth to") or infectious agent — colloquially, a germ — is a microbe or microorganism such as a virus, bacterium, prion, or fungus that causes disease in its animal or plant host...
s that cause meningitis. This discrepancy is addressed by the probability of infection by means other than sexual contact. In general, an STI is an infection that has a negligible probability of transmission by means other than sexual contact, but has a realistic means of transmission by sexual contact (more sophisticated means—blood transfusion
Blood transfusion
Blood transfusion is the process of receiving blood products into one's circulation intravenously. Transfusions are used in a variety of medical conditions to replace lost components of the blood...
, sharing of hypodermic needle
Hypodermic needle
A hypodermic needle is a hollow needle commonly used with a syringe to inject substances into the body or extract fluids from it...
s—are not taken into account). Thus, one may presume that, if a person is infected with an STI, e.g., chlamydia, gonorrhea
Gonorrhea
Gonorrhea is a common sexually transmitted infection caused by the bacterium Neisseria gonorrhoeae. The usual symptoms in men are burning with urination and penile discharge. Women, on the other hand, are asymptomatic half the time or have vaginal discharge and pelvic pain...
, genital herpes, it was transmitted to him/her by means of sexual contact.
The diseases on this list are most commonly transmitted solely by sexual activity. Many infectious diseases, including the common cold
Common cold
The common cold is a viral infectious disease of the upper respiratory system, caused primarily by rhinoviruses and coronaviruses. Common symptoms include a cough, sore throat, runny nose, and fever...
, influenza
Influenza
Influenza, commonly referred to as the flu, is an infectious disease caused by RNA viruses of the family Orthomyxoviridae , that affects birds and mammals...
, pneumonia
Pneumonia
Pneumonia is an inflammatory condition of the lung—especially affecting the microscopic air sacs —associated with fever, chest symptoms, and a lack of air space on a chest X-ray. Pneumonia is typically caused by an infection but there are a number of other causes...
, and most others that are transmitted person-to-person can also be transmitted during sexual contact, if one person is infected, due to the close contact involved. However, even though these diseases may be transmitted during sex, they are not considered STDs.
Bacterial
- ChancroidChancroidChancroid is a sexually transmitted infection characterized by painful sores on the genitalia...
(Haemophilus ducreyiHaemophilus ducreyiHaemophilus ducreyi is a fastidious gram-negative coccobacillus causing the sexually transmitted disease chancroid, a major cause of genital ulceration in developing countries characterized by painful sores on the genitalia. Another early symptom is dark or light green shears in excrement...
) - Chlamydia (Chlamydia trachomatisChlamydia trachomatisChlamydia trachomatis, an obligate intracellular human pathogen, is one of three bacterial species in the genus Chlamydia. C. trachomatis is a Gram-negative bacteria, therefore its cell wall components retain the counter-stain safranin and appear pink under a light microscope.The inclusion bodies...
) - Granuloma inguinale or (Klebsiella granulomatisKlebsiella granulomatisKlebsiella granulomatis is Gram-negative, rod shaped bacteria of the genus Klebsiella known to cause the sexually transmitted disease Donovanosis. It used to be called Calymmatobacterium granulomatis....
) - GonorrheaGonorrheaGonorrhea is a common sexually transmitted infection caused by the bacterium Neisseria gonorrhoeae. The usual symptoms in men are burning with urination and penile discharge. Women, on the other hand, are asymptomatic half the time or have vaginal discharge and pelvic pain...
(Neisseria gonorrhoeaeNeisseria gonorrhoeaeNeisseria gonorrhoeae, also known as gonococci , or gonococcus , is a species of Gram-negative coffee bean-shaped diplococci bacteria responsible for the sexually transmitted infection gonorrhea.N...
) - SyphilisSyphilisSyphilis is a sexually transmitted infection caused by the spirochete bacterium Treponema pallidum subspecies pallidum. The primary route of transmission is through sexual contact; however, it may also be transmitted from mother to fetus during pregnancy or at birth, resulting in congenital syphilis...
(Treponema pallidumTreponema pallidumTreponema pallidum is a species of spirochaete bacterium with subspecies that cause treponemal diseases such as syphilis, bejel, pinta and yaws. The treponemes have a cytoplasmic and outer membrane...
)
Viral
- Viral hepatitisViral hepatitisViral hepatitis is liver inflammation due to a viral infection. It may present in acute or chronic forms. The most common causes of viral hepatitis are the five unrelated hepatotropic viruses Hepatitis A, Hepatitis B, Hepatitis C, Hepatitis D, and Hepatitis E...
(Hepatitis B virusHepatitis B virusHepatitis B is an infectious illness caused by hepatitis B virus which infects the liver of hominoidea, including humans, and causes an inflammation called hepatitis. Originally known as "serum hepatitis", the disease has caused epidemics in parts of Asia and Africa, and it is endemic in China...
)—saliva, venereal fluids.
(Note: Hepatitis AHepatitis AHepatitis A is an acute infectious disease of the liver caused by the hepatitis A virus , an RNA virus, usually spread the fecal-oral route; transmitted person-to-person by ingestion of contaminated food or water or through direct contact with an infectious person...
and Hepatitis EHepatitis EHepatitis E is a viral hepatitis caused by infection with a virus called hepatitis E virus . HEV is a positive-sense single-stranded RNA icosahedral virus with a 7.5 kilobase genome. HEV has a fecal-oral transmission route. It is one of five known hepatitis viruses: A, B, C, D, and E...
are transmitted via the fecal-oral routeFecal-oral routeThe fecal-oral route, or alternatively, the oral-fecal route or orofecal route is a route of transmission of diseases, in which they are passed when pathogens in fecal particles from one host are introduced into the oral cavity of another potential host.There are usually intermediate steps,...
; Hepatitis CHepatitis CHepatitis C is an infectious disease primarily affecting the liver, caused by the hepatitis C virus . The infection is often asymptomatic, but chronic infection can lead to scarring of the liver and ultimately to cirrhosis, which is generally apparent after many years...
is rarely sexually transmittable, and the route of transmission of Hepatitis DHepatitis DHepatitis D, also referred to as hepatitis D virus and classified as Hepatitis delta virus, is a disease caused by a small circular enveloped RNA virus. It is one of five known hepatitis viruses: A, B, C, D, and E. HDV is considered to be a subviral satellite because it can propagate only in the...
(only if infected with B) is uncertain, but may include sexual transmission.) - Herpes simplexHerpes simplexHerpes simplex is a viral disease caused by both Herpes simplex virus type 1 and type 2 . Infection with the herpes virus is categorized into one of several distinct disorders based on the site of infection. Oral herpes, the visible symptoms of which are colloquially called cold sores or fever...
(Herpes simplex virusHerpes simplex virusHerpes simplex virus 1 and 2 , also known as Human herpes virus 1 and 2 , are two members of the herpes virus family, Herpesviridae, that infect humans. Both HSV-1 and HSV-2 are ubiquitous and contagious...
1, 2) skin and mucosal, transmissible with or without visible blisters - HIVHIVHuman immunodeficiency virus is a lentivirus that causes acquired immunodeficiency syndrome , a condition in humans in which progressive failure of the immune system allows life-threatening opportunistic infections and cancers to thrive...
(Human Immunodeficiency Virus)—venereal fluids, semen, breast milk, blood - HPV (Human Papillomavirus)—skin and mucosal contact. 'High risk' types of HPV cause almost all cervical cancerCervical cancerCervical cancer is malignant neoplasm of the cervix uteri or cervical area. One of the most common symptoms is abnormal vaginal bleeding, but in some cases there may be no obvious symptoms until the cancer is in its advanced stages...
s, as well as some analAnal cancerAnal cancer is a type of cancer which arises from the anus, the distal orifice of the gastrointestinal tract. It is a distinct entity from the more common colorectal cancer. The etiology, risk factors, clinical progression, staging, and treatment are all different. Anal cancer is typically a...
, penile, and vulvar cancerVulvar cancerVulvar cancer, a malignant invasive growth in the vulva, accounts for about 4 % of all gynecological cancers and typically affects women in later life. It is estimated that in the United States in 2006 about 3,740 new cases will be diagnosed and about 880 women will die as a result of vulvar cancer...
. Some other types of HPV cause genital warts. - Molluscum contagiosumMolluscum contagiosumMolluscum contagiosum is a viral infection of the skin or occasionally of the mucous membranes. It is caused by a DNA poxvirus called the molluscum contagiosum virus . MCV has no animal reservoir, infecting only humans. There are four types of MCV, MCV-1 to -4; MCV-1 is the most prevalent and...
(molluscum contagiosum virusMolluscum contagiosum virusThe Molluscum contagiosum virus or MCV is a species of virus in the poxvirus family, which causes the disease Molluscum contagiosum in humans. Virions have a complex structure and is consistent with the structure of the poxvirus family: an envelope, surface membrane, core, and lateral bodies...
MCV)—close contact
Parasites
- Crab louseCrab louseCrab lice are parasitic insects notorious for infesting human pubic hair. The species may also live on other areas with hair, including the eyelashes. They feed exclusively on blood...
, colloquially known as "crabs" or "pubic lice" (Pthirus pubis) - ScabiesScabiesScabies , known colloquially as the seven-year itch, is a contagious skin infection that occurs among humans and other animals. It is caused by a tiny and usually not directly visible parasite, the mite Sarcoptes scabiei, which burrows under the host's skin, causing intense allergic itching...
(Sarcoptes scabieiSarcoptes scabieiSarcoptes scabiei or the itch mite is a parasitic arthropod that burrows into skin and causes scabies. Animals affected include not only human but also wild and domesticated dogs and cats in which it is one cause of mange...
)
Transmission probability
The risks and transmission probabilities of sexually transmitted diseases are summarized by act in the table below.| Odds of transmission per unprotected sexual act with an infected person | ||
|---|---|---|
| Known risks | Possible or unknown risks | |
| Performing oral sex on a man Fellatio Fellatio is an act of oral stimulation of a male's penis by a sexual partner. It involves the stimulation of the penis by the use of the mouth, tongue, or throat. The person who performs fellatio can be referred to as the giving partner, and the other person is the receiving partner... |
With ass to mouth Ass to mouth Ass to mouth is a colloquial term used in pornographic movies. It refers to the withdrawal of a man's penis from the receptive partner's anus followed by the immediate insertion of the penis into the receptive partner's or another partner's mouth.... practices:
|
HIV Human immunodeficiency virus is a lentivirus that causes acquired immunodeficiency syndrome , a condition in humans in which progressive failure of the immune system allows life-threatening opportunistic infections and cancers to thrive... (very low risk; 0.01%) Hepatitis C Hepatitis C is an infectious disease primarily affecting the liver, caused by the hepatitis C virus . The infection is often asymptomatic, but chronic infection can lead to scarring of the liver and ultimately to cirrhosis, which is generally apparent after many years... (unknown) |
| Performing oral sex on a woman Cunnilingus Cunnilingus is an oral sex act performed on a female. It involves the use by a sex partner of the mouth, lips and tongue to stimulate the female's clitoris, vulva, or vagina... |
Herpes simplex Herpes simplex is a viral disease caused by both Herpes simplex virus type 1 and type 2 . Infection with the herpes virus is categorized into one of several distinct disorders based on the site of infection. Oral herpes, the visible symptoms of which are colloquially called cold sores or fever... (1%) |
Human papillomavirus Human papillomavirus is a member of the papillomavirus family of viruses that is capable of infecting humans. Like all papillomaviruses, HPVs establish productive infections only in keratinocytes of the skin or mucous membranes... |
| Receiving oral sex - man Fellatio Fellatio is an act of oral stimulation of a male's penis by a sexual partner. It involves the stimulation of the penis by the use of the mouth, tongue, or throat. The person who performs fellatio can be referred to as the giving partner, and the other person is the receiving partner... |
Gonorrhea Gonorrhea is a common sexually transmitted infection caused by the bacterium Neisseria gonorrhoeae. The usual symptoms in men are burning with urination and penile discharge. Women, on the other hand, are asymptomatic half the time or have vaginal discharge and pelvic pain... Non-gonococcal urethritis Nongonococcal urethritis is an inflammation of the urethra that is not caused by gonorrheal infection.For treatment purposes, doctors usually classify infectious urethritis in two categories: gonococcal urethritis, caused by gonorrhea, and nongonococcal urethritis .-Causes:There are many causes of... Herpes simplex Herpes simplex is a viral disease caused by both Herpes simplex virus type 1 and type 2 . Infection with the herpes virus is categorized into one of several distinct disorders based on the site of infection. Oral herpes, the visible symptoms of which are colloquially called cold sores or fever... Syphilis Syphilis is a sexually transmitted infection caused by the spirochete bacterium Treponema pallidum subspecies pallidum. The primary route of transmission is through sexual contact; however, it may also be transmitted from mother to fetus during pregnancy or at birth, resulting in congenital syphilis... (1%) |
Human papillomavirus Human papillomavirus is a member of the papillomavirus family of viruses that is capable of infecting humans. Like all papillomaviruses, HPVs establish productive infections only in keratinocytes of the skin or mucous membranes... |
| Receiving oral sex - woman Cunnilingus Cunnilingus is an oral sex act performed on a female. It involves the use by a sex partner of the mouth, lips and tongue to stimulate the female's clitoris, vulva, or vagina... |
Herpes simplex Herpes simplex is a viral disease caused by both Herpes simplex virus type 1 and type 2 . Infection with the herpes virus is categorized into one of several distinct disorders based on the site of infection. Oral herpes, the visible symptoms of which are colloquially called cold sores or fever... |
Human papillomavirus Human papillomavirus is a member of the papillomavirus family of viruses that is capable of infecting humans. Like all papillomaviruses, HPVs establish productive infections only in keratinocytes of the skin or mucous membranes... |
| Vaginal sex - man Sexual intercourse Sexual intercourse, also known as copulation or coitus, commonly refers to the act in which a male's penis enters a female's vagina for the purposes of sexual pleasure or reproduction. The entities may be of opposite sexes, or they may be hermaphroditic, as is the case with snails... |
Crab louse Crab lice are parasitic insects notorious for infesting human pubic hair. The species may also live on other areas with hair, including the eyelashes. They feed exclusively on blood... Scabies Scabies , known colloquially as the seven-year itch, is a contagious skin infection that occurs among humans and other animals. It is caused by a tiny and usually not directly visible parasite, the mite Sarcoptes scabiei, which burrows under the host's skin, causing intense allergic itching... Gonorrhea Gonorrhea is a common sexually transmitted infection caused by the bacterium Neisseria gonorrhoeae. The usual symptoms in men are burning with urination and penile discharge. Women, on the other hand, are asymptomatic half the time or have vaginal discharge and pelvic pain... (20%) Herpes simplex Herpes simplex is a viral disease caused by both Herpes simplex virus type 1 and type 2 . Infection with the herpes virus is categorized into one of several distinct disorders based on the site of infection. Oral herpes, the visible symptoms of which are colloquially called cold sores or fever... HIV Human immunodeficiency virus is a lentivirus that causes acquired immunodeficiency syndrome , a condition in humans in which progressive failure of the immune system allows life-threatening opportunistic infections and cancers to thrive... (0.05%) Human papillomavirus Human papillomavirus is a member of the papillomavirus family of viruses that is capable of infecting humans. Like all papillomaviruses, HPVs establish productive infections only in keratinocytes of the skin or mucous membranes... (at least 5%) Non-gonococcal urethritis Nongonococcal urethritis is an inflammation of the urethra that is not caused by gonorrheal infection.For treatment purposes, doctors usually classify infectious urethritis in two categories: gonococcal urethritis, caused by gonorrhea, and nongonococcal urethritis .-Causes:There are many causes of... Syphilis Syphilis is a sexually transmitted infection caused by the spirochete bacterium Treponema pallidum subspecies pallidum. The primary route of transmission is through sexual contact; however, it may also be transmitted from mother to fetus during pregnancy or at birth, resulting in congenital syphilis... Trichomoniasis Trichomoniasis, sometimes referred to as "trich", is a common cause of vaginitis. It is a sexually transmitted disease, and is caused by the single-celled protozoan parasite Trichomonas vaginalis producing mechanical stress on host cells and then ingesting cell fragments after cell death... |
Hepatitis C Hepatitis C is an infectious disease primarily affecting the liver, caused by the hepatitis C virus . The infection is often asymptomatic, but chronic infection can lead to scarring of the liver and ultimately to cirrhosis, which is generally apparent after many years... |
| Vaginal sex - woman Sexual intercourse Sexual intercourse, also known as copulation or coitus, commonly refers to the act in which a male's penis enters a female's vagina for the purposes of sexual pleasure or reproduction. The entities may be of opposite sexes, or they may be hermaphroditic, as is the case with snails... |
Crab louse Crab lice are parasitic insects notorious for infesting human pubic hair. The species may also live on other areas with hair, including the eyelashes. They feed exclusively on blood... Scabies Scabies , known colloquially as the seven-year itch, is a contagious skin infection that occurs among humans and other animals. It is caused by a tiny and usually not directly visible parasite, the mite Sarcoptes scabiei, which burrows under the host's skin, causing intense allergic itching... Gonorrhea Gonorrhea is a common sexually transmitted infection caused by the bacterium Neisseria gonorrhoeae. The usual symptoms in men are burning with urination and penile discharge. Women, on the other hand, are asymptomatic half the time or have vaginal discharge and pelvic pain... (50 to 90%) Herpes simplex Herpes simplex is a viral disease caused by both Herpes simplex virus type 1 and type 2 . Infection with the herpes virus is categorized into one of several distinct disorders based on the site of infection. Oral herpes, the visible symptoms of which are colloquially called cold sores or fever... HIV Human immunodeficiency virus is a lentivirus that causes acquired immunodeficiency syndrome , a condition in humans in which progressive failure of the immune system allows life-threatening opportunistic infections and cancers to thrive... (0.1%) Human papillomavirus Human papillomavirus is a member of the papillomavirus family of viruses that is capable of infecting humans. Like all papillomaviruses, HPVs establish productive infections only in keratinocytes of the skin or mucous membranes... (high; at least 5%) Syphilis Syphilis is a sexually transmitted infection caused by the spirochete bacterium Treponema pallidum subspecies pallidum. The primary route of transmission is through sexual contact; however, it may also be transmitted from mother to fetus during pregnancy or at birth, resulting in congenital syphilis... Trichomoniasis Trichomoniasis, sometimes referred to as "trich", is a common cause of vaginitis. It is a sexually transmitted disease, and is caused by the single-celled protozoan parasite Trichomonas vaginalis producing mechanical stress on host cells and then ingesting cell fragments after cell death... |
Hepatitis C Hepatitis C is an infectious disease primarily affecting the liver, caused by the hepatitis C virus . The infection is often asymptomatic, but chronic infection can lead to scarring of the liver and ultimately to cirrhosis, which is generally apparent after many years... |
| Anal sex - insertive Anal sex Anal sex is the sex act in which the penis is inserted into the anus of a sexual partner. The term can also include other sexual acts involving the anus, including pegging, anilingus , fingering, and object insertion.Common misconception describes anal sex as practiced almost exclusively by gay men... |
Crab louse Crab lice are parasitic insects notorious for infesting human pubic hair. The species may also live on other areas with hair, including the eyelashes. They feed exclusively on blood... Scabies Scabies , known colloquially as the seven-year itch, is a contagious skin infection that occurs among humans and other animals. It is caused by a tiny and usually not directly visible parasite, the mite Sarcoptes scabiei, which burrows under the host's skin, causing intense allergic itching... (40%) Gonorrhea Gonorrhea is a common sexually transmitted infection caused by the bacterium Neisseria gonorrhoeae. The usual symptoms in men are burning with urination and penile discharge. Women, on the other hand, are asymptomatic half the time or have vaginal discharge and pelvic pain... Herpes simplex Herpes simplex is a viral disease caused by both Herpes simplex virus type 1 and type 2 . Infection with the herpes virus is categorized into one of several distinct disorders based on the site of infection. Oral herpes, the visible symptoms of which are colloquially called cold sores or fever... HIV Human immunodeficiency virus is a lentivirus that causes acquired immunodeficiency syndrome , a condition in humans in which progressive failure of the immune system allows life-threatening opportunistic infections and cancers to thrive... (0.62%) Human papillomavirus Human papillomavirus is a member of the papillomavirus family of viruses that is capable of infecting humans. Like all papillomaviruses, HPVs establish productive infections only in keratinocytes of the skin or mucous membranes... Non-gonococcal urethritis Nongonococcal urethritis is an inflammation of the urethra that is not caused by gonorrheal infection.For treatment purposes, doctors usually classify infectious urethritis in two categories: gonococcal urethritis, caused by gonorrhea, and nongonococcal urethritis .-Causes:There are many causes of... Syphilis Syphilis is a sexually transmitted infection caused by the spirochete bacterium Treponema pallidum subspecies pallidum. The primary route of transmission is through sexual contact; however, it may also be transmitted from mother to fetus during pregnancy or at birth, resulting in congenital syphilis... (14%) |
Hepatitis C Hepatitis C is an infectious disease primarily affecting the liver, caused by the hepatitis C virus . The infection is often asymptomatic, but chronic infection can lead to scarring of the liver and ultimately to cirrhosis, which is generally apparent after many years... |
| Anal sex - receptive Anal sex Anal sex is the sex act in which the penis is inserted into the anus of a sexual partner. The term can also include other sexual acts involving the anus, including pegging, anilingus , fingering, and object insertion.Common misconception describes anal sex as practiced almost exclusively by gay men... |
Crab louse Crab lice are parasitic insects notorious for infesting human pubic hair. The species may also live on other areas with hair, including the eyelashes. They feed exclusively on blood... Scabies Scabies , known colloquially as the seven-year itch, is a contagious skin infection that occurs among humans and other animals. It is caused by a tiny and usually not directly visible parasite, the mite Sarcoptes scabiei, which burrows under the host's skin, causing intense allergic itching... Gonorrhea Gonorrhea is a common sexually transmitted infection caused by the bacterium Neisseria gonorrhoeae. The usual symptoms in men are burning with urination and penile discharge. Women, on the other hand, are asymptomatic half the time or have vaginal discharge and pelvic pain... Herpes simplex Herpes simplex is a viral disease caused by both Herpes simplex virus type 1 and type 2 . Infection with the herpes virus is categorized into one of several distinct disorders based on the site of infection. Oral herpes, the visible symptoms of which are colloquially called cold sores or fever... HIV Human immunodeficiency virus is a lentivirus that causes acquired immunodeficiency syndrome , a condition in humans in which progressive failure of the immune system allows life-threatening opportunistic infections and cancers to thrive... (1.7%) Human papillomavirus Human papillomavirus is a member of the papillomavirus family of viruses that is capable of infecting humans. Like all papillomaviruses, HPVs establish productive infections only in keratinocytes of the skin or mucous membranes... Syphilis Syphilis is a sexually transmitted infection caused by the spirochete bacterium Treponema pallidum subspecies pallidum. The primary route of transmission is through sexual contact; however, it may also be transmitted from mother to fetus during pregnancy or at birth, resulting in congenital syphilis... (1.4%) |
Hepatitis C Hepatitis C is an infectious disease primarily affecting the liver, caused by the hepatitis C virus . The infection is often asymptomatic, but chronic infection can lead to scarring of the liver and ultimately to cirrhosis, which is generally apparent after many years... |
| Oral-anal sex |
Cryptosporidiosis Cryptosporidiosis, also known as crypto, is a parasitic disease caused by Cryptosporidium, a protozoan parasite in the phylum Apicomplexa. It affects the intestines of mammals and is typically an acute short-term infection... (1%) Giardiasis Giardiasis or beaver fever in humans is a diarrheal infection of the small intestine by a single-celled organism Giardia lamblia. Giardiasis occurs worldwide with a prevalence of 20–30% in developing countries. In the U.S., 20,000 cases are reported to the CDC annually, but the true annual... Hepatitis A Hepatitis A is an acute infectious disease of the liver caused by the hepatitis A virus , an RNA virus, usually spread the fecal-oral route; transmitted person-to-person by ingestion of contaminated food or water or through direct contact with an infectious person... (1%) Shigellosis Shigellosis, also known as bacillary dysentery or Marlow Syndrome, in its most severe manifestation, is a foodborne illness caused by infection by bacteria of the genus Shigella. Shigellosis rarely occurs in animals other than humans and other primates like monkeys and chimpanzees... (1%) |
Human papillomavirus Human papillomavirus is a member of the papillomavirus family of viruses that is capable of infecting humans. Like all papillomaviruses, HPVs establish productive infections only in keratinocytes of the skin or mucous membranes... (1%) |
Pathophysiology
Many STDs are (more easily) transmitted through the mucous membraneMucous membrane
The mucous membranes are linings of mostly endodermal origin, covered in epithelium, which are involved in absorption and secretion. They line cavities that are exposed to the external environment and internal organs...
s of the penis
Penis
The penis is a biological feature of male animals including both vertebrates and invertebrates...
, vulva
Vulva
The vulva consists of the external genital organs of the female mammal. This article deals with the vulva of the human being, although the structures are similar for other mammals....
, rectum
Rectum
The rectum is the final straight portion of the large intestine in some mammals, and the gut in others, terminating in the anus. The human rectum is about 12 cm long...
, urinary tract and (less often—depending on type of infection) the mouth
Mouth
The mouth is the first portion of the alimentary canal that receives food andsaliva. The oral mucosa is the mucous membrane epithelium lining the inside of the mouth....
, throat
Throat
In vertebrate anatomy, the throat is the anterior part of the neck, in front of the vertebral column. It consists of the pharynx and larynx...
, respiratory tract
Respiratory tract
In humans the respiratory tract is the part of the anatomy involved with the process of respiration.The respiratory tract is divided into 3 segments:*Upper respiratory tract: nose and nasal passages, paranasal sinuses, and throat or pharynx...
and eyes. The visible membrane covering the head of the penis
Glans penis
The glans penis is the sensitive bulbous structure at the distal end of the penis. The glans penis is anatomically homologous to the clitoral glans of the female...
is a mucous membrane, though it produces no mucus
Mucus
In vertebrates, mucus is a slippery secretion produced by, and covering, mucous membranes. Mucous fluid is typically produced from mucous cells found in mucous glands. Mucous cells secrete products that are rich in glycoproteins and water. Mucous fluid may also originate from mixed glands, which...
(similar to the lip
Lip
Lips are a visible body part at the mouth of humans and many animals. Lips are soft, movable, and serve as the opening for food intake and in the articulation of sound and speech...
s of the mouth). Mucous membranes differ from skin
Skin
-Dermis:The dermis is the layer of skin beneath the epidermis that consists of connective tissue and cushions the body from stress and strain. The dermis is tightly connected to the epidermis by a basement membrane. It also harbors many Mechanoreceptors that provide the sense of touch and heat...
in that they allow certain pathogens into the body. Pathogens are also able to pass through breaks or abrasions of the skin, even minute ones. The shaft of the penis is particularly susceptible due to the friction caused during penetrative sex. The primary sources of infection in ascending order are venereal fluids, saliva, mucosal or skin (particularly the penis), infections may also be transmitted from feces, urine and sweat. 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.
This is one reason that the probability of transmitting many infections is far higher from sex than by more casual means of transmission, such as non-sexual contact—touching, hugging, shaking hands—but it is not the only reason. Although mucous membrane
Mucous membrane
The mucous membranes are linings of mostly endodermal origin, covered in epithelium, which are involved in absorption and secretion. They line cavities that are exposed to the external environment and internal organs...
s exist in the mouth as in the genitals, many STIs seem to be easier to transmit through oral sex
Oral sex
Oral sex is sexual activity involving the stimulation of the genitalia of a sex partner by the use of the mouth, tongue, teeth or throat. Cunnilingus refers to oral sex performed on females while fellatio refer to oral sex performed on males. Anilingus refers to oral stimulation of a person's anus...
than through deep kissing. According to a safe sex chart, many infections that are easily transmitted from the mouth to the genitals or from the genitals to the mouth, are much harder to transmit from one mouth to another. With HIV
HIV
Human immunodeficiency virus is a lentivirus that causes acquired immunodeficiency syndrome , a condition in humans in which progressive failure of the immune system allows life-threatening opportunistic infections and cancers to thrive...
, genital fluids happen to contain much more of the pathogen
Pathogen
A pathogen gignomai "I give birth to") or infectious agent — colloquially, a germ — is a microbe or microorganism such as a virus, bacterium, prion, or fungus that causes disease in its animal or plant host...
than saliva
Saliva
Saliva , referred to in various contexts as spit, spittle, drivel, drool, or slobber, is the watery substance produced in the mouths of humans and most other animals. Saliva is a component of oral fluid. In mammals, saliva is produced in and secreted from the three pairs of major salivary glands,...
. Some infections labeled as STIs can be transmitted by direct skin
Skin
-Dermis:The dermis is the layer of skin beneath the epidermis that consists of connective tissue and cushions the body from stress and strain. The dermis is tightly connected to the epidermis by a basement membrane. It also harbors many Mechanoreceptors that provide the sense of touch and heat...
contact. Herpes simplex
Herpes simplex
Herpes simplex is a viral disease caused by both Herpes simplex virus type 1 and type 2 . Infection with the herpes virus is categorized into one of several distinct disorders based on the site of infection. Oral herpes, the visible symptoms of which are colloquially called cold sores or fever...
and HPV are both examples. KSHV
Kaposi's sarcoma-associated herpesvirus
Kaposi's sarcoma-associated herpesvirus is one of seven currently known human cancer viruses, or oncoviruses. It is also the eighth human herpesvirus; its formal name according to the International Committee on Taxonomy of Viruses is HHV-8. Like other herpesviruses, its informal name is used...
, on the other hand, may be transmitted by deep-kissing but also when saliva is used as a sexual lubricant.
Depending on the STD, a person may still be able to spread the infection if no signs of disease are present. For example, a person is much more likely to spread herpes infection when blister
Blister
A blister is a small pocket of fluid within the upper layers of the skin, typically caused by forceful rubbing , burning, freezing, chemical exposure or infection. Most blisters are filled with a clear fluid called serum or plasma...
s are present (STD) than when they are absent (STI). However, a person can spread HIV
HIV
Human immunodeficiency virus is a lentivirus that causes acquired immunodeficiency syndrome , a condition in humans in which progressive failure of the immune system allows life-threatening opportunistic infections and cancers to thrive...
infection (STI) at any time, even if he/she has not developed symptoms of AIDS
AIDS
Acquired immune deficiency syndrome or acquired immunodeficiency syndrome is a disease of the human immune system caused by the human immunodeficiency virus...
(STD).
All sexual behaviors
Human sexual behavior
Human sexual activities or human sexual practices or human sexual behavior refers to the manner in which humans experience and express their sexuality. People engage in a variety of sexual acts from time to time, and for a wide variety of reasons...
that involve contact with the bodily fluids of another person should be considered to contain some risk of transmission of sexually transmitted diseases. Most attention has focused on controlling HIV
HIV
Human immunodeficiency virus is a lentivirus that causes acquired immunodeficiency syndrome , a condition in humans in which progressive failure of the immune system allows life-threatening opportunistic infections and cancers to thrive...
, which causes AIDS
AIDS
Acquired immune deficiency syndrome or acquired immunodeficiency syndrome is a disease of the human immune system caused by the human immunodeficiency virus...
, but each STD presents a different situation.
As may be noted from the name, sexually transmitted diseases are transmitted from one person to another by certain sexual activities rather than being actually caused by those sexual activities. Bacteria, fungi, protozoa
Protozoa
Protozoa are a diverse group of single-cells eukaryotic organisms, many of which are motile. Throughout history, protozoa have been defined as single-cell protists with animal-like behavior, e.g., movement...
or virus
Virus
A virus is a small infectious agent that can replicate only inside the living cells of organisms. Viruses infect all types of organisms, from animals and plants to bacteria and archaea...
es are still the causative agents. It is not possible to catch any sexually transmitted disease from a sexual activity with a person who is not carrying a disease; conversely, a person who has an STD got it from contact (sexual or otherwise) with someone who had it, or his/her bodily fluids. Some STDs such as HIV can be transmitted from mother to child either during pregnancy or breastfeeding.
Although the likelihood of transmitting various diseases by various sexual activities varies a great deal, in general, all sexual activities between two (or more) people should be considered as being a two-way route for the transmission of STDs, i.e., "giving" or "receiving" are both risky although receiving carries a higher risk.
Healthcare professionals suggest safer sex, such as the use of condoms, as the most reliable way of decreasing the risk of contracting sexually transmitted diseases during sexual activity, but safer sex should by no means be considered an absolute safeguard. The transfer of and exposure to bodily fluids, such as blood transfusion
Blood transfusion
Blood transfusion is the process of receiving blood products into one's circulation intravenously. Transfusions are used in a variety of medical conditions to replace lost components of the blood...
s and other blood products, sharing injection needles
Intravenous therapy
Intravenous therapy or IV therapy is the infusion of liquid substances directly into a vein. The word intravenous simply means "within a vein". Therapies administered intravenously are often called specialty pharmaceuticals...
, needle-stick injuries (when medical staff are inadvertently jabbed or pricked with needles during medical procedures), sharing tattoo
Tattoo
A tattoo is made by inserting indelible ink into the dermis layer of the skin to change the pigment. Tattoos on humans are a type of body modification, and tattoos on other animals are most commonly used for identification purposes...
needles, and childbirth are other avenues of transmission. These different means put certain groups, such as medical workers, and haemophilia
Haemophilia
Haemophilia is a group of hereditary genetic disorders that impair the body's ability to control blood clotting or coagulation, which is used to stop bleeding when a blood vessel is broken. Haemophilia A is the most common form of the disorder, present in about 1 in 5,000–10,000 male births...
cs and drug users, particularly at risk.
Recent epidemiological
Epidemiology
Epidemiology is the study of health-event, health-characteristic, or health-determinant patterns in a population. It is the cornerstone method of public health research, and helps inform policy decisions and evidence-based medicine by identifying risk factors for disease and targets for preventive...
studies have investigated the networks that are defined by sexual relationships between individuals, and discovered that the properties of sexual network
Sexual network
A sexual network is a social network that is defined by the sexual relationships within a set of individuals.-Studies and discoveries:Like other forms of social networks, sexual networks can be formally studied using the mathematics of graph theory and network theory.Recent epidemiological studies ...
s are crucial to the spread of sexually transmitted diseases. In particular, assortative mixing
Assortative mixing
In the study of complex networks, assortative mixing, or assortativity, is a bias in favor of connections between network nodes with similar characteristics. In the specific case of social networks, assortative mixing is also known as homophily...
between people with large numbers of sexual partners seems to be an important factor.
It is possible to be an asymptomatic
Symptom
A symptom is a departure from normal function or feeling which is noticed by a patient, indicating the presence of disease or abnormality...
carrier of sexually transmitted diseases. In particular, sexually transmitted diseases in women often cause the serious condition of pelvic inflammatory disease
Pelvic inflammatory disease
Pelvic inflammatory disease is a generic term for inflammation of the uterus, fallopian tubes, and/or ovaries as it progresses to scar formation with adhesions to nearby tissues and organs. This may lead to infections. PID is a vague term and can refer to viral, fungal, parasitic, though most...
.
Prevention
Prevention is key in addressing incurable STIs, such as HIV & herpes. Sexual health clinicSexual health clinic
Sexual health clinics specialize in the prevention and treatment of sexually transmitted infections.Sexual health clinics provide only some reproductive health services...
s fight to promote the use of condoms and provide outreach for at-risk communities.
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
Cybersex, also called computer sex, Internet sex, netsex, mudsex, TinySex and, colloquially, cybering, is a virtual sex encounter in which two or more persons connected remotely via computer network send each other sexually explicit messages describing a sexual experience...
, phonesex or masturbation
Masturbation
Masturbation refers to sexual stimulation of a person's own genitals, usually to the point of orgasm. The stimulation can be performed manually, by use of objects or tools, or by some combination of these methods. Masturbation is a common form of autoeroticism...
from a distance are methods of avoiding contact. Proper use of condom
Condom
A condom is a barrier device most commonly used during sexual intercourse to reduce the probability of pregnancy and spreading sexually transmitted diseases . It is put on a man's erect penis and physically blocks ejaculated semen from entering the body of a sexual partner...
s reduces contact and risk. Although a condom is effective in limiting exposure, some disease transmission may occur even with a condom.
Ideally, both partners should 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 with current medical procedures.
Many diseases that establish permanent infections can so occupy the immune system that other diseases become more easily transmitted. The innate immune system
Innate immune system
The innate immune system, also known as non-specific immune system and secondary line of defence, comprises the cells and mechanisms that defend the host from infection by other organisms in a non-specific manner...
led by defensins against HIV can prevent transmission of HIV when viral counts are very low, but if busy with other viruses or overwhelmed, HIV can establish itself. Certain viral STI's also greatly increase the risk of death for HIV infected patients.
Vaccines
Vaccines are available that protect against some viral STIs, such as Hepatitis AHepatitis A vaccine
Hepatitis A vaccine is a vaccine against the hepatitis A virus. The first successful vaccine against it was invented by Maurice Hilleman at Merck. The vaccine protects against the virus in more than 95% of cases and provides protection from the virus for at least ten years...
, Hepatitis B
Hepatitis B vaccine
Hepatitis B vaccine is a vaccine developed for the prevention of hepatitis B virus infection. The vaccine contains one of the viral envelope proteins, hepatitis B surface antigen . It is produced by yeast cells, into which the genetic code for HBsAg has been inserted...
, and some types of HPV
HPV vaccine
The human papilloma virus vaccine prevents infection with certain species of human papillomavirus associated with the development of cervical cancer, genital warts, and some less common cancers...
. Vaccination before initiation of sexual contact is advised to assure maximal protection.
Condoms
CondomCondom
A condom is a barrier device most commonly used during sexual intercourse to reduce the probability of pregnancy and spreading sexually transmitted diseases . It is put on a man's erect penis and physically blocks ejaculated semen from entering the body of a sexual partner...
s and female condom
Female condom
A female condom is a device that is used during sexual intercourse as a barrier contraceptive and to reduce the risk of sexually transmitted infections and unintended pregnancy...
s only provide protection when used properly as a barrier, and only to and from the area that it covers. Uncovered areas are still susceptible to many STDs. In the case of HIV, sexual transmission routes almost always involve the penis, as HIV cannot spread through unbroken skin, thus properly shielding the insertive 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 having open bleeding wounds. Other STDs, 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 usage entails:
- Not putting the condom on too tight at the end, and leaving 1.5 cm (3/4 inch) room at the tip for ejaculationEjaculationEjaculation is the ejecting of semen from the male reproductory tract, and is usually accompanied by orgasm. It is usually the final stage and natural objective of male sexual stimulation, and an essential component of natural conception. In rare cases ejaculation occurs because of prostatic disease...
. Putting the condom on snug can and often does lead to failure. - Wearing a condom too loose can defeat the barrier.
- Avoiding inverting, spilling a condom once worn, whether it has ejaculate in it or not.
- Avoiding condoms made of substances other than latex, polyisoprene or polyurethane that do not protect against HIV.
- 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.
Not following the first five guidelines above perpetuates the common misconception that condoms are not tested or designed properly.
In order to best protect oneself and the partner from STIs, the old condom and its contents should be assumed to be infectious. Therefore the old condom must be properly disposed of. A new condom should be used for each act of intercourse, as multiple usage increases the chance of breakage, defeating the effectiveness as a barrier.
Nonoxynol-9
Researchers had hoped that nonoxynol-9Nonoxynol-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. It is widely used in contraceptives for its...
, a vaginal microbicide would help decrease STD rates. Trials, however, have found it ineffective. In fact, the use of nonoxynol-9 can put women at a higher risk of HIV infection.
Diagnosis
STI testsMedical test
A diagnostic test is any kind of medical test performed to aid in the diagnosis or detection of disease. For example:* to diagnose diseases, and preferably sub-classify it regarding, for example, severity and treatability...
may test for a single infection, or consist of a number of individual tests for any of a wide range of STIs, including tests for syphilis
Syphilis
Syphilis is a sexually transmitted infection caused by the spirochete bacterium Treponema pallidum subspecies pallidum. The primary route of transmission is through sexual contact; however, it may also be transmitted from mother to fetus during pregnancy or at birth, resulting in congenital syphilis...
, trichomonas
Trichomonas
Trichomonas is a genus of anaerobic protists that are parasites of vertebrates. They are included with the parabasalids.Species of Trichomonas include:*Trichomonas vaginalis, an organism generally living inside the vagina of humans...
, gonorrhea
Gonorrhea
Gonorrhea is a common sexually transmitted infection caused by the bacterium Neisseria gonorrhoeae. The usual symptoms in men are burning with urination and penile discharge. Women, on the other hand, are asymptomatic half the time or have vaginal discharge and pelvic pain...
, chlamydia, herpes, hepatitis
Hepatitis
Hepatitis is a medical condition defined by the inflammation of the liver and characterized by the presence of inflammatory cells in the tissue of the organ. The name is from the Greek hepar , the root being hepat- , meaning liver, and suffix -itis, meaning "inflammation"...
and HIV test
HIV test
HIV tests are used to detect the presence of the human immunodeficiency virus , the virus that causes acquired immunodeficiency syndrome , in serum, saliva, or urine. Such tests may detect antibodies, antigens, or RNA.- Terminology :...
s. No procedure tests for all infectious agents.
STI tests may be used for a number of reasons:
- as a diagnostic test to determine the cause of symptoms or illness
- as a screening test to detect asymptomatic or presymptomatic infectionInfectionAn infection is the colonization of a host organism by parasite species. Infecting parasites seek to use the host's resources to reproduce, often resulting in disease...
s - as a check that prospective sexual partners are free of disease before they engage in sex without safer sex 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 bloodBlood donationA blood donation occurs when a person voluntarily has blood drawn and used for transfusions or made into medications by a process called fractionation....
or organOrgan donationOrgan donation is the donation of biological tissue or an organ of the human body, from a living or dead person to a living recipient in need of a transplantation. Transplantable organs and tissues are removed in a surgical procedure following a determination, based on the donor's medical and...
s - as part of the process of contact tracingContact tracingIn epidemiology, contact tracing is the identification and diagnosis of persons who may have come into contact with an infected person. For sexually transmitted diseases, this is generally limited to sexual partners but for highly virulent diseases such as Ebola and tuberculosis, a thorough contact...
from a known infected individual - as part of mass epidemiological surveillance
Not all STIs are symptom
Symptom
A symptom is a departure from normal function or feeling which is noticed by a patient, indicating the presence of disease or abnormality...
atic, 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
Infertility
Infertility primarily refers to the biological inability of a person to contribute to conception. Infertility may also refer to the state of a woman who is unable to carry a pregnancy to full term...
, chronic pain
Chronic pain
Chronic pain has several different meanings in medicine. Traditionally, the distinction between acute and chronic pain has relied upon an arbitrary interval of time from onset; the two most commonly used markers being 3 months and 6 months since the initiation of pain, though some theorists and...
or even death. 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
Window period
In medicine, the window period for a test designed to detect a specific disease is the time between first infection and when the test can reliably detect that infection...
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 afflicted people turn to the Internet rather than to a medical professional for information on STIs to a higher degree than for other sexual problems.
STD Wizard
The STD Wizard is a publicly available expert systemExpert system
In artificial intelligence, an expert system is a computer system that emulates the decision-making ability of a human expert. Expert systems are designed to solve complex problems by reasoning about knowledge, like an expert, and not by following the procedure of a developer as is the case in...
for determining which screening tests, vaccinations, and evaluations are recommended, related to sexually transmitted diseases. The information included within the STD Wizard is based on the Centers for Disease Control and Prevention
Centers for Disease Control and Prevention
The Centers for Disease Control and Prevention are a United States federal agency under the Department of Health and Human Services headquartered in Druid Hills, unincorporated DeKalb County, Georgia, in Greater Atlanta...
"Sexually Transmitted Diseases Treatment Guidelines - 2006". The system has English and Spanish language interfaces.
The STD Wizard runs in a web browser. The program asks a series of questions, related to demographics, behaviors, and symptoms. There are potentially over 100 questions, but most users get asked about 20. The exact questions asked depend on the user's responses. Typical questions include:
- Demographics - How old are you, in years?
- Behaviors - Have you had more than one sex partner within the past six months?
- Symptoms - Are you having a discharge from your penis or burning during urination?
Typical recommendations include:
- Screening tests - e.g., HIV screening testHIV testHIV tests are used to detect the presence of the human immunodeficiency virus , the virus that causes acquired immunodeficiency syndrome , in serum, saliva, or urine. Such tests may detect antibodies, antigens, or RNA.- Terminology :...
- Vaccinations - e.g., Hepatitis B vaccinationHepatitis B vaccineHepatitis B vaccine is a vaccine developed for the prevention of hepatitis B virus infection. The vaccine contains one of the viral envelope proteins, hepatitis B surface antigen . It is produced by yeast cells, into which the genetic code for HBsAg has been inserted...
- Evaluations - e.g., Seek medical attention in the next week for rash
Management
High risk exposure such as that which occurs in rape cases may be treated prophylacticly using antibiotic combinations such as azithromycinAzithromycin
Azithromycin is an azalide, a subclass of macrolide antibiotics. Azithromycin is one of the world's best-selling antibiotics...
, cefixime
Cefixime
Cefixime is an oral third generation cephalosporin antibiotic. Cefixime is a cephalosporin antibiotic used to treat infections caused by bacteria such as pneumonia; bronchitis; gonorrhea; and ear, lung, throat, and urinary tract infections...
, and metronidazole
Metronidazole
Metronidazole is a nitroimidazole antibiotic medication used particularly for anaerobic bacteria and protozoa. Metronidazole is an antibiotic, amebicide, and antiprotozoal....
.
An option for treating partners of patients (index cases) diagnosed with chlamydia or gonorrhea
Gonorrhea
Gonorrhea is a common sexually transmitted infection caused by the bacterium Neisseria gonorrhoeae. The usual symptoms in men are burning with urination and penile discharge. Women, on the other hand, are asymptomatic half the time or have vaginal discharge and pelvic pain...
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.
Epidemiology
STD incidence rates remain high in most of the world, despite diagnostic and therapeutic advances that can rapidly render patients with many STDs noninfectious and cure most. In many cultures, changing sexual morals and oral contraceptive use have eliminated traditional sexual restraints, especially for women, and both physicians and patients have difficulty dealing openly and candidly with sexual issues. Additionally, development and spread of drug-resistant bacteriaDrug resistance
Drug resistance is the reduction in effectiveness of a drug such as an antimicrobial or an antineoplastic in curing a disease or condition. When the drug is not intended to kill or inhibit a pathogen, then the term is equivalent to dosage failure or drug tolerance. More commonly, the term is used...
(e.g., penicillin-resistant gonococci) makes some STDs harder to cure. The effect of travel is most dramatically illustrated by the rapid spread of the AIDS
AIDS
Acquired immune deficiency syndrome or acquired immunodeficiency syndrome is a disease of the human immune system caused by the human immunodeficiency virus...
virus (HIV-1) from Africa to Europe and the Americas in the late 1970s.
In 1996, the World Health Organization
World Health Organization
The World Health Organization is a specialized agency of the United Nations that acts as a coordinating authority on international public health. Established on 7 April 1948, with headquarters in Geneva, Switzerland, the agency inherited the mandate and resources of its predecessor, the Health...
estimated that more than 1 million people were being infected daily. About 60% of these infections occur in young people <25 years of age, and of these 30% are <20 years. Between the ages of 14 and 19, STDs occur more frequently in girls than boys by a ratio of nearly 2:1; this equalizes by age 20. An estimated 340 million new cases of syphilis, gonorrhea, chlamydia and trichomoniasis occurred throughout the world in 1999.
Commonly reported prevalences of STIs among sexually active adolescent girls both with and without lower genital tract symptoms include chlamydia (10–25%), gonorrhea
Gonorrhea
Gonorrhea is a common sexually transmitted infection caused by the bacterium Neisseria gonorrhoeae. The usual symptoms in men are burning with urination and penile discharge. Women, on the other hand, are asymptomatic half the time or have vaginal discharge and pelvic pain...
(3–18%), syphilis
Syphilis
Syphilis is a sexually transmitted infection caused by the spirochete bacterium Treponema pallidum subspecies pallidum. The primary route of transmission is through sexual contact; however, it may also be transmitted from mother to fetus during pregnancy or at birth, resulting in congenital syphilis...
(0–3%), Trichomonas vaginalis
Trichomonas vaginalis
Trichomonas vaginalis is an anaerobic, flagellated protozoan, a form of microorganism. The parasitic microorganism is the causative agent of trichomoniasis, and is the most common pathogenic protozoan infection of humans in industrialized countries. Infection rates between men and women are the...
(8–16%), and herpes simplex virus (2–12%). Among adolescent boys with no symptoms of urethritis, isolation rates include chlamydia (9–11%) and gonorrhea (2–3%).
At least one in four U.S. teenage girls has a sexually transmitted disease, a CDC
Centers for Disease Control and Prevention
The Centers for Disease Control and Prevention are a United States federal agency under the Department of Health and Human Services headquartered in Druid Hills, unincorporated DeKalb County, Georgia, in Greater Atlanta...
study found. Among girls who admitted ever having sex, the rate was 40%.
AIDS
AIDS
Acquired immune deficiency syndrome or acquired immunodeficiency syndrome is a disease of the human immune system caused by the human immunodeficiency virus...
is the single largest cause of mortality in present-day Sub-Saharan Africa
Sub-Saharan Africa
Sub-Saharan Africa as a geographical term refers to the area of the African continent which lies south of the Sahara. A political definition of Sub-Saharan Africa, instead, covers all African countries which are fully or partially located south of the Sahara...
. The majority of HIV
HIV
Human immunodeficiency virus is a lentivirus that causes acquired immunodeficiency syndrome , a condition in humans in which progressive failure of the immune system allows life-threatening opportunistic infections and cancers to thrive...
infections are acquired through unprotected sexual relations between partners, one of whom has HIV. Approximately 1.1 million persons are living with HIV/AIDS in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
, and AIDS remains the leading cause of death among African American
African American
African Americans are citizens or residents of the United States who have at least partial ancestry from any of the native populations of Sub-Saharan Africa and are the direct descendants of enslaved Africans within the boundaries of the present United States...
women between ages 25 and 34. Hepatitis B is also classed as a sexually transmitted disease because it can be passed on sexually. The disease is found globally, with the highest rates in Asia and Africa and lower rates in the Americas and Europe. Worldwide, an estimated two billion people have been infected with the hepatitis B virus.
History
The first well-recorded European outbreak of what is now known as syphilisSyphilis
Syphilis is a sexually transmitted infection caused by the spirochete bacterium Treponema pallidum subspecies pallidum. The primary route of transmission is through sexual contact; however, it may also be transmitted from mother to fetus during pregnancy or at birth, resulting in congenital syphilis...
occurred in 1494 when it broke out among French troops besieging Naples
Naples
Naples is a city in Southern Italy, situated on the country's west coast by the Gulf of Naples. Lying between two notable volcanic regions, Mount Vesuvius and the Phlegraean Fields, it is the capital of the region of Campania and of the province of Naples...
. From this centre, the disease swept across Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
, killing more than five million people. As Jared Diamond
Jared Diamond
Jared Mason Diamond is an American scientist and author whose work draws from a variety of fields. He is currently Professor of Geography and Physiology at UCLA...
describes it, "[W]hen syphilis was first definitely recorded in Europe in 1495, its pustules 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
Fatal may refer to:* Causing death* Fatal , an album by Hussein Fatal* Fatal Recordings, a feminist record label* Fatal, a rapper who collaborated with the band Therapy? on the song "Come and Die" from the Judgment Night film soundtrack...
than it is today. Diamond concludes,"[B]y 1546, the disease had evolved into the disease with the symptoms so well known to us today."
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
London Lock Hospital
The London Lock Hospital was the first venereal disease clinic, being the most famous and first of the Lock Hospitals, which opened on 31 January 1747....
. Treatment was not always voluntary: in the second half of the 19th century, the Contagious Diseases Act was used to arrest suspected prostitutes.
The first effective treatment for a sexually transmitted disease was salvarsan
Arsphenamine
Arsphenamine, also known as Salvarsan and 606, is a drug that was used beginning in the 1910s to treat syphilis and trypanosomiasis...
, a treatment for syphilis. With the discovery of antibiotic
Antibiotic
An antibacterial is a compound or substance that kills or slows down the growth of bacteria.The term is often used synonymously with the term antibiotic; today, however, with increased knowledge of the causative agents of various infectious diseases, antibiotic has come to denote a broader range of...
s, a large number of sexually transmitted diseases became easily curable, and this, combined with effective public health campaigns against STDs, 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
Contact tracing
In epidemiology, contact tracing is the identification and diagnosis of persons who may have come into contact with an infected person. For sexually transmitted diseases, this is generally limited to sexual partners but for highly virulent diseases such as Ebola and tuberculosis, a thorough contact...
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 be very effective at suppressing infections in the general population.
In the 1980s, first genital herpes and then AIDS
AIDS
Acquired immune deficiency syndrome or acquired immunodeficiency syndrome is a disease of the human immune system caused by the human immunodeficiency virus...
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 HIV
HIV
Human immunodeficiency virus is a lentivirus that causes acquired immunodeficiency syndrome , a condition in humans in which progressive failure of the immune system allows life-threatening opportunistic infections and cancers to thrive...
(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 in about 1969 likely through a single infected immigrant from Haiti. Recognition that AIDS threatened a global pandemic
Pandemic
A pandemic is an epidemic of infectious disease that is spreading through human populations across a large region; for instance multiple continents, or even worldwide. A widespread endemic disease that is stable in terms of how many people are getting sick from it is not a 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.
External links
- CDC Sexually Transmitted Diseases Treatment Guidelines, 2010
- Sexually Transmitted Diseases Treatment Guidelines - 2006
- STD photo library at DermnetNew Zealand Dermatological SocietyThe New Zealand Dermatological Society is a medical organization best known outside New Zealand for its "DermNet" website, which provides photographs and descriptions of many skin conditions. The website was started in 1996....
- UNFPA: Breaking the Cycle of Sexually Transmitted Infections at UNFPAUnited Nations Population FundThe United Nations Population Fund is a UN organization. The work of the UNFPA involves promotion of the right of every woman, man and child to enjoy a life of health and equal opportunity. This is done through major national and demographic surveys and with population censuses...
- Sexually Transmitted Infections from the National Institute of Allergy and Infectious DiseasesNational Institute of Allergy and Infectious DiseasesThe National Institute of Allergy and Infectious Diseases is one of the 27 institutes and centers that make up the National Institutes of Health , an agency of the United States Department of Health and Human Services...
- STDs In Color: Sexually Transmitted Disease Facts and Photos
- http://wonder.cdc.gov/std.html: Sexually Transmitted Diseases in the U.S.