Sexually Transmitted Diseases (STDs)

STDs, also known as sexually transmitted infections (STIs), are typically caused by bacteria or viruses and are passed from person to person during sexual contact with the penis, vagina, anus, or mouth. The symptoms of STDs/STIs vary between individuals, depending on the cause, and many people may not experience symptoms at all.

Many STDs/STIs have significant health consequences. For instance, certain STIs can also increase the risk of getting and transmitting HIV/AIDS and alter the way the disease progresses. STIs can also cause long-term health problems, particularly in women and infants. Some of the health problems that arise from STIs include pelvic inflammatory disease, infertility, tubal or ectopic pregnancy, cervical cancer, and perinatal or congenital infections in infants.

NICHD's research also focuses on understanding sexual risk-taking behaviors that increase the likelihood of individuals contracting STIs, on developing more effective educational interventions to prevent STIs, and on defining the consequences and optimal treatments for STIs, especially in pregnant women.

About Sexually Transmitted Diseases (STDs)

STDs/STIs are a group of illnesses that are passed from person to person during sexual intercourse, oral sex, or certain types of sex play. These diseases can be caused by bacteria, viruses, or parasites and are spread through intimate sexual contact involving the penis, vagina, mouth, or anus or contact with any of the membranes that line the urinary and/or genital tracts. STDs/STIs are also called venereal diseases.

Health care providers often use the term "infection" rather than "disease" because it is possible for a person to have no symptoms but still have the infection and require treatment. Scientists have identified more than 20 different STIs.1

Learn more about STDs from the Centers for Disease Control and Prevention website.


  1. MedlinePlus. (2014). Sexually transmitted diseases. Retrieved December 22, 2015, from 

What are the symptoms of sexually transmitted diseases (STDs) or sexually transmitted infections (STIs)?

People with STDs/STIs may feel ill and notice some of the following signs and symptoms:1,2

  • Unusual discharge from the penis or vagina
  • Sores or warts on the genital area
  • Painful or frequent urination
  • Itching and redness in the genital area
  • Blisters or sores in or around the mouth
  • Abnormal vaginal odor
  • Anal itching, soreness, or bleeding
  • Abdominal pain
  • Fever

In some cases, people with STIs have no symptoms. Over time, any symptoms that are present may improve on their own. It is also possible for a person to have an STI with no symptoms and then pass it on to others without knowing it.

If you are concerned that you or your sexual partner may have an STI, talk to your health care provider. Even if you do not have symptoms, it is possible you may have an STI that needs treatment to ensure your and your partners’ sexual health.


  1. NIH (2008). Understanding, treating, and preventing STDs/Questions to ask your health care professional. NIH Medline Plus, 3(4), 18–19. Retrieved December 22, 2015, from
  2. (2009). Sexually transmitted infections (STI). Retrieved December 22, 2015, from 

What causes sexually transmitted diseases (STDs) or sexually transmitted infections (STIs)?

There are three major causes of STDs/STIs:

  • Bacteria, including chlamydia, gonorrhea, and syphilis
  • Viruses, including HIV/AIDS, herpes simplex virus, human papillomavirus, hepatitis B virus, cytomegalovirus (CMV), and Zika
  • Parasites, such as trichomonas vaginalis, or insects such as crab lice or scabies mites1

Any STI can be spread through sexual activity including sexual intercourse, and some STIs also are spread through oral sex and other sexual activity. Ejaculation does not have to occur for an STI to pass from person to person.

In addition, sharing contaminated needles, such as those used to inject drugs, or using contaminated body piercing or tattooing equipment also can transmit some infections, such as HIV, hepatitis B, and hepatitis C. A few infections can be sexually transmitted but are also spread through nonsexual, close contact. Some of these infections, like CMV, are not considered STIs even though they can be transmitted through sexual contact.

Regardless of how a person is exposed, once a person is infected by an STI, he or she can spread the infection to other people through oral, vaginal, or anal sex, even if he or she has no symptoms.


  1. Medline Plus. Sexually transmitted diseases. Retrieved December 23, 2015, from

What are some types of and treatments for sexually transmitted diseases (STDs) or sexually transmitted infections (STIs)?

Approximately 20 different infections are known to be transmitted through sexual contact. Although NICHD does study STIs, their prevention, and their effects on pregnancy and long-term health, the Institute is not the lead agency aiming to understand STIs. For more complete information about STIs, you may want to visit or

Here are descriptions of some common STIs.

  • Caused by the bacterium Chlamydia trachomatis
  • Can be transmitted during vaginal, oral, or anal sexual contact with an infected partner
  • Many infected individuals will not experience symptoms, but chlamydia can cause fever, abdominal pain, and unusual discharge from the penis or vagina.
  • Can be treated with antibiotics
  • If untreated, can cause pelvic inflammatory disease, which can lead to chronic pelvic pain and permanent damage to a woman's reproductive organs. This damage may lead to ectopic pregnancy (in which the fetus develops outside of the womb, a condition that can be life-threatening) and infertility.
  • Can be transmitted to fetus during pregnancy or to infant during delivery, causing eye infections or pneumonia. Antibiotic ointment is usually applied to a baby's eyes after birth to treat undetected chlamydia.
  • Because chlamydia and gonorrhea often occur together, people who have one infection are typically treated for both by their health care provider.
  • To prevent health complications and sexual transmission, treatment should be provided promptly for all persons testing positive for infection, and recent sexual partners should be treated at the same time to prevent reinfection.
  • Infected individuals should follow their health care provider's recommendations about how long to abstain from sex after the treatment is completed to avoid passing the infection back and forth.1 

  • Caused by the bacterium Neisseria gonorrhoeae, which can grow and multiply rapidly in the warm, moist areas of the reproductive tract
  • Most common symptoms include discharge from the vagina or penis and painful or difficult urination.2
  • Can be treated with antibiotics
  • Like chlamydia, if left untreated, gonorrhea can cause pelvic inflammatory disease, which can lead to chronic pelvic pain and permanent damage to a woman's reproductive organs. This damage may lead to ectopic pregnancy (in which the fetus develops outside of the womb, a condition that can be life-threatening) and infertility.2
  • In both men and women, gonorrhea can also infect the mouth, throat, eyes, and rectum and can spread to the blood and joints, where it can become a life-threatening illness.
  • Can be transmitted to the fetus during pregnancy2
  • Because chlamydia and gonorrhea often occur together, people who have one infection are typically treated for both by their health care provider.
  • To prevent health complications and sexual transmission, treatment should be provided promptly for all persons testing positive for infection, and recent sexual partners should be treated at the same time to prevent reinfection.
  • People with gonorrhea can more easily contract HIV, the virus that causes AIDS. HIV-infected people with gonorrhea are also more likely to transmit the virus to someone else.3

  • Caused by the herpes simplex virus (HSV)4
  • There are two different strains, or types: HSV type 1 (HSV-1) and type 2 (HSV-2). Both can cause genital herpes, although most cases of genital herpes are caused by HSV-2.5
  • Symptoms of HSV-1 usually appear as fever blisters or cold sores on the lips, but it can also infect the genital region through oral-genital or genital-genital contact. Symptoms of HSV-2 are typically painful, watery skin blisters on or around the genitals or anus. However, substantial numbers of people who carry these viruses have no or only minimal signs or symptoms.
  • Cannot be cured, but can be controlled with medication
  • One medication can be taken daily to make it less likely that the infection will pass on to sex partner(s) or to infants during childbirth.4
  • Periodically, some people will experience outbreaks of symptoms in which new blisters form on the skin in the genital area; at those times, the virus is more likely to be passed on to other people.
  • If a pregnant woman has an outbreak when she goes into labor, she may need to have a cesarean section (C-section) to prevent the infant from getting the virus during birth.4
  • Pregnant women, especially those who acquire genital herpes for the first time during pregnancy, may pass the infection to their newborns, causing life-threatening neonatal HSV, an infection affecting the infant's skin, brain, and other organs.6

  • HIV, human immunodeficiency virus,7 is the virus that causes AIDS.
  • Destroys the body's immune system by killing the blood cells that fight infection. Once HIV destroys a substantial proportion of these cells, the body's ability to fight off and recover from infections is compromised. This advanced stage of HIV infection is known as AIDS.
  • People whose HIV infection has progressed to AIDS have a weakened immune system and are very susceptible to opportunistic infections that do not normally make people sick and to certain forms of cancer.
  • In people who do not have HIV, the infection can be prevented by many tools, including abstaining from sex, limiting the number of sexual partners, never sharing needles, and using condoms appropriately. Persons who may be at very high risk of HIV infection may be able to obtain HIV Pre-Exposure Prophylaxis or PrEP, which consists of the HIV medication called Truvada, from their doctor to take every day so they can prevent HIV infection. PrEP will not work if it is not taken consistently.
  • AIDS can be prevented in those with HIV infection by early initiation of antiretroviral therapy.
  • Transmission of the virus primarily occurs during unprotected sexual activity and by sharing needles used to inject intravenous drugs.
  • HIV can also spread from mother to fetus during pregnancy and from mother to infant during delivery and breastfeeding. However, treatments are available that can virtually eliminate these types of transmission.

  • HPV8 is the most common STI. More than 40 HPV types exist, and all of them can infect both men and women.
  • The types of HPVs vary in their ability to cause genital warts; infect other regions of the body, including the mouth and throat; and cause cancers of the cervix, vulva, penis, anus, and mouth.8
  • Cannot be cured but can be prevented with vaccines and controlled with medications
  • Genital warts caused by the virus8 can also be treated.
  • Regular screening with a Pap smear test can prevent or detect at an early stage most cases of HPV-caused cervical cancer. (A Pap smear test involves a health care provider taking samples of cells from the cervix during a standard gynecologic exam; these cells are examined under a microscope for signs of developing cancer).
  • Two available vaccines protect against most (but not all) HPV types that cause cervical cancer. A group advising the Centers for Disease Control and Prevention recommends this vaccine for boys and girls starting at 11 or 12 years old.9

  • Caused by the bacterium Treponema pallidum
  • Passes from person to person during vaginal, anal, or oral sex through direct contact with syphilis sores
  • Syphilis can also be spread from an infected mother to her fetus.10 In 2001, the number of cases of syphilis was at its lowest in 60 years. But the syphilis rate has increased nearly every year up to 2016, the most recent year for which data are available. Rates have increased among both men and women, but men account for a vast majority of syphilis cases.11 
  • The first sign of syphilis is a chancre, a painless genital sore that most often appears on the penis or in and around the vagina. Chancres typically resolve on their own, but the body does not clear the infection on its own.
  • Chancres make a person two to five times more likely to contract an HIV infection.10 If the person is already infected with HIV, chancres also increase the likelihood that the HIV virus will be passed on to a sexual partner.3 
  • Can be treated with antibiotics:
    • If recognized during the early stages, usually within the first year of infection, syphilis can be treated with a single injection of antibiotic.
    • If not recognized early, or not treated immediately, syphilis may need longer treatment with antibiotics.
  • Without treatment:
    • Usually spreads to other organs, including the skin, heart, blood vessels, liver, bones, and joints in secondary syphilis.
    • Other sores, such as a syphilis rash, can break out in later stages.
    • Tertiary syphilis can develop over a period of years and involve the nerves, eyes, and brain and can potentially cause death.
  • Can pass to the fetus during pregnancy and to the infant during delivery
  • Infants who get syphilis infection in the womb may have misshapen bones, very low red blood cell count (called severe anemia), enlarged liver and spleen, jaundice (yellowing of the skin or eyes), nerve problems, blindness or deafness, meningitis, and skin rashes.12
  • Those being treated for syphilis must avoid sexual contact until the syphilis sores are completely healed to avoid infecting other people.
  • Persons with syphilis must notify their sex partners so that they also can be tested and receive treatment if necessary.
  • Pregnant women with syphilis, especially untreated syphilis, are at an increased risk of miscarriage and stillbirth.

  • Occurs when problematic bacteria that are normally present only in small amounts in the body increase in number. Their levels get so high that they replace normal vaginal bacteria and upset the usual balance.
  • More likely if a woman douches frequently or has new or multiple sexual partners
  • Most common symptom is a thin, milky discharge that is often described as having a "fishy" odor. However, some women will have no symptoms at all.
  • Can be treated with antibiotics, typically metronidazole or clindamycin
  • Generally, sexual partners of women with bacterial vaginosis do not need to be treated because treatment of partners has not been shown to reduce the risk of recurrence.
  • Treatment is recommended for all pregnant women who show symptoms.13
  • Increases the risk of getting other STIs even if the woman doesn't have any symptoms
  • Associated with preterm labor and birth and having a low birth weight baby
  • Also associated with pelvic inflammatory disease, an infection of the female reproductive organs, including the uterus and the fallopian tubes (which carry eggs to the uterus), and with infections that commonly occur after surgery13

  • Caused14 by the single-celled parasite Trichomonas vaginalis
  • Common in young, sexually active women but also infects men, though less frequently
  • The parasite can be transmitted between men and women as well as between women whenever physical contact occurs between the genital areas.
  • Can cause frequent, painful, or "burning" urination in men and women as well as vaginal discharge, genital soreness, redness, or itching in women. However, it may not cause any symptoms.
  • Because the infection can occur without symptoms, a person may be unaware that he or she is infected and continue to re-infect a sexual partner who is having recurrent signs of infection.
  • Can be treated with a single dose of an antibiotic, usually either metronidazole or tinidazole, taken by mouth
  • Because of re-infection, it is important to make sure that the diagnosed individual and all sexual partners are treated at the same time.
  • Retesting is recommended for all sexually active women within 3 months after initial treatment even if they believe their partners were treated.15
  • Infection during pregnancy is associated with an increased risk of preterm labor or birth and infants with low birth weight.
  • Stillbirth and newborn death are more than twice as likely among pregnant women with Trichomonas infection than among uninfected pregnant women.16

  • Caused by several different viral strains
  • More information about hepatitis A, B, and C can be found on the Centers for Disease Control and Prevention website.
  • Hepatitis A virus (HAV):
    • Causes a short-term or self-limited liver infection that can be quite serious.
    • Does not result in chronic infection.
    • Can be transmitted during sexual activity and through oral-anal contact.
    • Vaccination can prevent HAV infection.17
    • May cause abdominal pain, nausea, and vomiting.
    • Usually the infection gets better on its own without requiring treatment. In some cases, however, individuals may have such severe nausea and vomiting that they must be admitted to the hospital or may have lasting damage to their livers.18
  • Hepatitis B virus (HBV):
    • Causes a serious liver infection that can result in both immediate illness and lifelong infection and disease, leading to permanent liver scarring (cirrhosis), cancer, liver failure, and death.
    • Can be treated with antiviral medications.
    • Vaccination can prevent HBV infection.
    • Spreads through sexual contact, as well as through contact with other bodily fluids, such as blood; through shared contaminated needles used for injecting intravenous drugs; and through tattooing and piercing.
    • Pregnant women with HBV can transmit the virus to their infants during delivery, but a series of vaccinations and a shot of hepatitis B immune globulin for the baby beginning at birth can prevent this transmission. Without vaccination, babies born to women with HBV infection can develop chronic infection, which can lead to serious health problems.19
    • People with chronic HBV infection will need to see a liver specialist with experience treating individuals with chronic liver disease. These individuals need to take special care not to pass on the virus to their sexual partners, and sexual partners should receive hepatitis B vaccine if they are not already immune.18
  • Hepatitis C virus (HCV):
    • Serious infection of the liver that can cause an immediate illness but that, in most people, becomes a silent, chronic infection that leads to liver scarring (cirrhosis), cancer, liver failure, and death
    • Most infected people may not be aware of their infection because they do not develop symptoms.
    • Most commonly transmitted through sharing needles or exposure to infected blood. Less commonly, it can spread through sexual contact or from mother to fetus during pregnancy and delivery.
    • Can be treated. New medications seem to be more effective and have fewer side effects than previous options. The Food and Drug Administration maintains a complete list of approved treatments for Hepatitis C.20

  • An infection caused by a virus. In most cases, it is spread by mosquitoes, but Zika virus also can be transmitted sexually.
  • Zika is usually mild, with symptoms lasting for several days to a week after being infected.
    • Research shows that getting Zika during pregnancy can cause birth defects in the developing fetus. In 2015, Zika virus infection was linked to microcephaly—a condition in which the brain and skull are smaller than normal—in newborns, as well as other birth defects.
    • Zika also was linked to problems with the adult nervous system, including Guillain-Barré Syndrome.
  • Pregnant women should not travel to areas with Zika. If you must travel to one of these areas, talk to your health care provider first and strictly follow steps to prevent mosquito bites during your trip.
  • Learn how to protect yourself and your partner from Zika during sex at
  • There is currently no specific medication or treatment for Zika infection.
  • The Centers for Disease Control and Prevention maintains a website with the latest information about Zika.


  1. Centers for Disease Control and Prevention. (2014). Chlamydia – CDC fact sheet. Retrieved May 27, 2016, from
  2. Centers for Disease Control and Prevention. (2014). Gonorrhea – CDC fact sheet. Retrieved May 27, 2016, from
  3. Centers for Disease Control and Prevention. (2015). HIV transmission. Retrieved May 27, 2016, from
  4. Centers for Disease Control and Prevention. (2014). Genital herpes – CDC fact sheet. Retrieved May 27, 2016, from
  5. Xu, F., Sternberg, M. R., Kottiri, B. J., McQuillan, G. M., Lee, F. K., Nahmias, A. J., et al. (2006). Trends in herpes simplex virus type 1 and type 2 seroprevalence in the United States. Journal of the American Medical Association, 296(8), 964–973.
  6. Marquez, L., Levy, M. L., Munoz, F. M., & Palazzi, D. L. (2011). A report of three cases and review of intrauterine herpes simplex virus infection. Pediatric Infectious Disease Journal, 30, 153–157.
  7. Centers for Disease Control and Prevention. (2016). About HIV/AIDS. Retrieved May 27, 2016, from
  8. Centers for Disease Control and Prevention. (2016). Genital HPV infection – CDC fact sheet. Retrieved May 27, 2016, from
  9. Petrosky, E., Bocchini, J. A. Jr., Hariri, S., Chesson, H., Curtis, C. R., Saraiya, M., et al. (2015). Use of 9-valent human papillomavirus (HPV) vaccine: Updated HPV vaccination recommendations of the Advisory Committee on Immunization Practices. Morbidity and Mortality Weekly Report, 64(11), 300–304. Retrieved May 27, 2016, from
  10. Centers for Disease Control and Prevention. (2015). Syphilis – CDC fact sheet (detailed). Retrieved December 24, 2015, from
  11. Centers for Disease Control and Prevention. (2018). 2016 Sexually transmitted disease surveillance. Retrieved May 4, 2018, from (PDF 2.53 MB)
  12. Centers for Disease Control and Prevention. (2015). Congenital syphilis – CDC fact sheet. Retrieved December 24, 2015, from
  13. Centers for Disease Control and Prevention. (2015). Bacterial vaginosis – CDC fact sheet. Retrieved December 24, 2015, from
  14. Centers for Disease Control and Prevention. (2015). Trichomoniasis – CDC fact sheet. Retrieved December 24, 2015, from
  15. Centers for Disease Control and Prevention. (2015). 2015 sexually transmitted diseases treatment guidelines: Trichomoniasis. Retrieved December 30, 2015, from
  16. Klebanoff, M. A., Carey, J. C., Hauth, J. C., Hillier, S. L., Nugent, R. P., Thom, E. A., et al.; National Institute of Child Health and Human Development Network of Maternal-Fetal Medicine Units. (2001). Failure of metronidazole to prevent preterm delivery among pregnant women with asymptomatic Trichomonas vaginalis infection. New England Journal of Medicine, 345, 487–493.
  17. Centers for Disease Control and Prevention. (2015). Hepatitis A questions and answers for the public. Retrieved December 24, 2015, from
  18. Centers for Disease Control and Prevention. (2015). 2015sexually transmitted diseases treatment guidelines: Viral hepatitis. Retrieved December 30, 2015, from
  19. Centers for Disease Control and Prevention. (2015). Hepatitis B FAQs for the public. Retrieved December 24, 2015, from
  20. Centers for Disease Control and Prevention. (2015). Hepatitis C FAQs for the public. Retrieved December 24, 2015, from

Why are sexually transmitted diseases (STDs) and sexually transmitted infections (STIs) of particular concern for pregnant women?

Some infections—such as Zika, gonorrhea, chlamydia, HIV, and syphilis—can pass to the fetus during pregnancy or to the infant during delivery, causing short- and long-term health problems. However, the risk of transmission can be lowered or even eliminated with appropriate treatments.

For this reason, it is important for a pregnant woman to be tested for STDs/STIs as a part of her prenatal care. Prenatal STI testing can determine whether a pregnant woman has an infection that can be cured or controlled with drug treatment, which decreases the chances that the infant will contract the disease.1 The pregnant woman and her health care provider can take other steps to protect her health and her infant's health if the STI is one that cannot be cured or treated.

Some examples of ways to reduce or eliminate risk of transmission include the following:

  • HIV can be passed from mother to infant during pregnancy before birth, at the time of delivery, or after birth during breastfeeding.2 Treatment during pregnancy near delivery prevents this transmission.
  • Recent research also shows that, for HIV-infected mothers whose immune system is in good health, treatment during breastfeeding virtually eliminates transmission of HIV through breastmilk.3 Women who have HIV but whose immune systems are not in good health should not breastfeed their infants if safe alternatives, such as infant formula, are available.1
  • If a woman has active herpes lesions, untreated HIV, or an HIV viral load that is not suppressed, the infant can be delivered by cesarean section (also referred to as C section) to prevent transmission of the infection.
  • For infections, such as gonorrhea, a pregnant woman and her sexual partner can be treated before the birth, and the infant can be treated at birth to prevent infection.1
  • In most hospitals, infants' eyes are routinely treated with an antibiotic ointment shortly after birth. The ointment can prevent blindness from exposure to gonorrhea or chlamydia bacteria during delivery, in case the pregnant woman had an undetected infection.
  • Women who are pregnant or are thinking about getting pregnant are advised not to travel to areas where Zika infection has been reported. Preventing mosquito bites can also reduce the risk for infection and transmission.

STIs during pregnancy can also cause:2

  • Miscarriage (fetal loss before 20 weeks)
  • Ectopic pregnancy (when the embryo implants outside of the uterus, usually in a fallopian tube)
  • Preterm labor and delivery (before 37 completed weeks of pregnancy)
  • Low birth weight
  • Birth defects, including blindness, microcephaly, deafness, bone deformities, and intellectual disability
  • Stillbirth (fetal loss at or after 20 weeks)
  • Illness in the newborn period (first month of life)
  • Newborn death
  • Health complications in the mother

Visit the What infections can affect pregnancy? section of this website for more information.


  1. Medline Plus. (2014). Genital herpes. Retrieved January 4, 2016, from
  2. American College of Obstetricians and Gynecologists. (2011). Frequently asked questions: HIV and pregnancy. Retrieved June 27, 2012, from  (PDF 328 KB)
  3. NIH. (2016). HIV therapy for breastfeeding mothers can virtually eliminate transmission to babies. Retrieved November 29, 2016, from

How do health care providers diagnose a sexually transmitted disease (STD) or sexually transmitted infection (STI)?

Any person who is sexually active should discuss his or her risk factors for STDs/STIs with a health care provider and ask about getting tested. If you are sexually active, it is important to remember that you may have an STD/STI and not know it because many STDs/STIs do not cause symptoms. You should get tested and have regular checkups with a health care provider who can help assess and manage your risk, answer your questions, and diagnose and treat an STD/STI if needed.

Starting treatment quickly is important to prevent transmission of infections to other people and to minimize the long-term complications of STDs/STIs. Recent sexual partners should also be treated to prevent re-infection and further transmission.

Some STDs/STIs may be diagnosed during a physical exam or through microscopic examination of a sore or fluid swabbed from the vagina, penis, or anus. This fluid can also be cultured over a few days to see whether infectious bacteria or yeast can be detected. The effects of human papilloma virus (HPV), which causes genital warts and cervical cancer, can be detected in a woman when her health care provider performs a pap smear test and takes samples of cells from the cervix to be checked microscopically for abnormal changes.1 Blood tests are used to detect infections such as hepatitis A, B, and C or HIV/AIDS.

Because sexually transmitted diseases are passed from person to person and can have serious health consequences, the health department notifies people if they have been exposed to certain STDs/STIs. Not all STDs/STIs are reported, though. If you receive a notice, it is important to see a health care provider, be tested, and start treatment right away.

Screening is especially important for pregnant women, because many STDs/STIs can be passed on to the fetus during pregnancy or delivery. During an early prenatal visit, with the help of her health care provider, an expectant mother should be screened for these infections, including HIV  and syphilis. Some of these STDs/STIs can be cured with drug treatment, but not all of them. However, even if the infection is not curable, a pregnant woman can usually take measures to protect her infant from infection.2


  1. Saslow, D., Solomon, D., Lawson, H. W., Killackey, M., Kulasingam, S. L., Cain, J., et al. ACS-ASCCP-ASCP Cervical Cancer Guideline Committee. (2012). American Cancer Society, American Society for Colposcopy and Cervical Pathology, and American Society for Clinical Pathology screening guidelines for the prevention and early detection of cervical cancer. CA: A Cancer Journal for Clinicians, 62, 147–172.
  2. Centers for Disease Control and Prevention. (2012, February 27). STDs & Pregnancy-CDC Fact Sheet. Retrieved July 11, 2012, from

Is there a cure for sexually transmitted diseases (STDs) and sexually transmitted infections (STIs)?

Viruses such as HIV, genital herpes, human papillomavirus, hepatitis, and cytomegalovirus cause STDs/STIs that cannot be cured. People with an STI caused by a virus will be infected for life and will always be at risk of infecting their sexual partners. However, treatments for these viruses can significantly reduce the risk of passing on the infection and can reduce or eliminate symptoms. STIs caused by bacteria, yeast, or parasites can be cured using appropriate medication.

What are the treatments for sexually transmitted diseases and sexually transmitted infections (STDs/STIs)?

STDs/STIs caused by bacteria or parasites can be treated with antibiotics. These antibiotics are most often given by mouth (orally). However, sometimes they are injected or applied directly to the affected area.

The treatments, complications, and outcomes for viral STIs depend on the particular virus (HIV, genital herpes, human papillomavirus, hepatitis, or cytomegalovirus). Treatments can reduce the symptoms and the progression of most of these infections. For example, medications are available to limit the frequency and severity of genital herpes outbreaks while reducing the risk that the virus will be passed on to other people.

Individuals with HIV need to take special antiretroviral drugs that control the amount of virus they carry. These drugs, called highly active antiretroviral therapy, or HAART,1 can help people live longer, healthier lives and can prevent onward transmission of HIV to others. If a woman with HIV becomes pregnant, these medicines also can reduce the chance that her fetus or infant will get the infection.

The Types and Treatments page of this website provides some general information about treatments for certain STIs. The Centers for Disease Control and Prevention website also provides more specific information about treatments for STIs.

Getting tested and treated for STIs is especially important for pregnant women because some STIs may be passed on during pregnancy or delivery. Testing women for these STIs early in their pregnancy is important so that steps can be taken to help ensure delivery of a healthy infant. The necessary treatment will depend on the type of STI involved.

Whatever the infection, and regardless of how quickly the symptoms resolve after beginning treatment, the infected person and their partner(s) must take all of the medicine prescribed by the health care provider to ensure that the STI is completely treated. Likewise, they should follow health care provider recommendations about how long to abstain from sex after the treatment is completed to avoid passing the infection back and forth.


  1. Panel on Antiretroviral Guidelines for Adults and Adolescents. (2015). Guidelines for the use of antiretroviral agents in HIV-1–infected adults and adolescents. Washington, DC: Department of Health and Human Services. Retrieved December 24, 2015, from

NICHD Sexually Transmitted Diseases (STDs) Research Goals

NICHD research on STDs/STIs ranges from identifying factors and behaviors that affect the risk of contracting or spreading STDs/STIs to understanding how STDs/STIs affect pregnancy and long-term health to developing and testing new interventions to prevent the spread of STDs/STIs in different populations. Also, since 1987, NICHD has supported research and training activities that have helped to establish and define the field of contraceptive microbicides, products that both prevent pregnancy and reduce the transmission of STIs, including HIV.

NICHD-supported researchers are also trying to understand the best ways to communicate with people about STIs and effective preventive measures. Some of this research includes studying attitudes, perception, and knowledge of STIs and their prevention; understanding the use and misuse of contraception to prevent STIs; and understanding the misinformation surrounding the topic while aiming to identify the best settings for providing education about sexual health.

Because preventing and treating STIs is a major goal for NIH and its Institutes, NICHD conducts and supports a variety of clinical trials on STIs, including HIV.

Sexually Transmitted Diseases (STDs) Research Activities and Advances

Research on STDs/sexually transmitted infections (STIs) falls into the portfolios of several NICHD organizational units. Some of their activities are explained below.

The Population Dynamics Branch (PDB) funds studies of sexual behaviors related to disease prevention in a variety of populations and intervention studies to modify risky sexual behaviors. This includes basic and intervention research on the demographic, social, and behavioral aspects of the sexual transmission of HIV and other STIs and the behaviors of individuals and couples in the prevention of unwanted pregnancy and disease. The Branch also promotes a population perspective on the HIV epidemic by examining the causes and consequences of the epidemic in and across populations.

Much of the Maternal and Pediatric Infectious Disease Branch's (MPIDB's) research focuses on HIV/AIDS and ways to prevent mother-to-child transmission and new infections. But the Branch also studies other STIs. For example, through MPIDB, NICHD co-funds the Microbicide Trials Network (MTN) to study the use of topical vaginal and rectal agents called microbicides, to prevent HIV and other STIs. The Network is also studying the use of these microbicides during pregnancy and breastfeeding to evaluate the safety of their use in women and infants. The Institute has also created several intervention programs that strive to understand factors that influence teen decision making regarding sexual behaviors that increase the risk of STIs.

Collaboration between the MTN and the Adolescent Medicine Trials Network for HIV/AIDS Interventions (ATN), which is co-funded by NICHD, continues to evaluate the safety of microbicides in adolescents, such as in the recent collaborative study (MTN 023) of a vaginal ring impregnated with the antiretroviral drug dapivirine that was recently shown to be effective in preventing HIV infection in adult women. The ATN's research also includes the development, adaptation, implementation, and evaluation of culturally appropriate, theory-driven behavioral preventive interventions for HIV and other STIs in at-risk youth.

The MPIDB is also leading NICHD research related to Zika virus. The Branch is collaborating on the Zika in Infants and Pregnancy study and is working to support additional research projects related to Zika. In addition, NICHD hosted a workshop on Zika exposure in the womb and long-term health outcomes. A meeting summary is currently in press.

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