14 Sexually Transmitted Diseases/Infections (STDs/STIs)

Objectives:

• Define STDs, explain how they are transmitted, and identify the most common STDs/STIs
• Identify the incidence, prevalence, and cost of STIs in the United States
• Learn prevention techniques and treatment options
• Develop a personal plan for STI prevention

What are STDs?

The following information about STDs is published by the Office of Disease Prevention and Health Promotion on the website Healthy People.gov., and is found on the page “Sexually Transmitted Diseases”:

STDs refer to more than 25 infectious organisms that are transmitted primarily through sexual activity. STD prevention is an essential primary care strategy for improving reproductive health.¹

Despite their burdens, costs, and complications, and the fact that they are largely preventable, STDs remain a significant public health problem in the United States. This problem is largely unrecognized by the public, policymakers, and health care professionals. STDs cause many harmful, often irreversible, and costly clinical complications, such as:

• Reproductive health problems
• Fetal and perinatal health problems
• Cancer
• Facilitation of the sexual transmission of HIV infection²

How are STDs Transmitted?

Ejaculation does not have to occur for an STD/STI to be passed from person to person. Sharing contaminated needles used to inject drugs or using contaminated body piercing and tattooing equipment also can transmit some infections, such as HIV or hepatitis B and C.

Below you will find additional information about the transmission of STDs. This information is published by the US Department of Health and Human Services and found on the website of the National Institutes of Health (NIH) on the page “How many people are affected by or at risk for a sexually transmitted disease or sexually transmitted infection (STD/STI)?”:

Anyone who has had or is having sexual intercourse or oral sex, or who has participated or is participating in sex play, is at risk for acquiring an STD/STI

Fortunately, it is possible for a person to decrease his or her risk by having protected sex and knowing his or her STD/STI status and that of his or her partner.

Still, the Centers for Disease Control and Prevention (CDC) estimates nearly 20 million new cases of these reportable STDs/STIs (gonorrhea, chlamydia, syphilis) occur each year in the United States— almost half of them among young people 15 to 24 years of age.¹

While not the most common STD/STI, HIV/AIDS is one of the most devastating and most well known. Recent data from the CDC indicate that 1.1 million Americans have HIV^2:

• One in five is unaware that they have the virus.
• Approximately 50,000 Americans become infected with HIV each year.
• 15,529 people with AIDS died in 2010.

Click on the following link to learn more about reported STDs in the United States:

CDC Fact Sheet

What are the Most Common Types of STIs?

The following information about the most common STIs is published by the US Department of Health and Human Services and found on the NIH’s website on the page “What are some types of sexually transmitted diseases or sexually transmitted infections (STDs/STIs)?”:

Approximately 20 different infections are known to be transmitted through sexual contact. Here are descriptions of some of the most common and well known:

Chlamydia

Chlamydia¹ (pronounced kla-MID-ee-uh) is a common STD/STI caused by the bacterium Chlamydia trachomatis. Chlamydia can be transmitted during vaginal, oral, or anal sexual contact with an infected partner.

While many individuals will not experience symptoms, chlamydia can cause fever, abdominal pain, and unusual discharge of the penis or vagina.

In women, whether or not they are having symptoms and know about their infection, chlamydia can cause pelvic inflammatory disease (PID). In PID, the untreated STD/STI progresses and involves other parts of the woman’s reproductive system, including the uterus and fallopian tubes. This progression can lead to permanent damage to the woman’s reproductive organs. This damage may lead to ectopic pregnancy (in which the fetus develops in abnormal places outside of the womb, a condition that can be life- threatening) and infertility.

Additionally, if the woman is pregnant, her developing fetus is at risk, because chlamydia can be passed on during her pregnancy or delivery and could lead to eye infections or pneumonia in the infant. If chlamydia is detected early, it can be treated easily with an antibiotic taken by mouth.

Gonorrhea

Gonorrhea² (pronounced gon-uh-REE-uh) is caused by the bacterium Neisseria gonorrhoeae, which can grow rapidly and multiply easily in the warm, moist areas of the reproductive tract. The most common symptoms of gonorrheal infection are a discharge from the vagina or penis and painful or difficult urination.

As with chlamydial infection, the most common and serious complications of gonorrhea occur in women and include pelvic inflammatory disease (PID), ectopic pregnancy, infertility, and the potential spread to the developing fetus if acquired during pregnancy. Gonorrhea also can infect the mouth, throat, eyes, and rectum and can spread to the blood and joints, where it can become a life-threatening illness.

In addition, 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

Genital Herpes

Genital herpes⁴ is a contagious infection caused by the herpes simplex virus (HSV). There are two different strains, or types, of HSV: herpes simplex virus 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 When symptomatic, HSV-1 usually appears as fever blisters or cold sores on the lips, but it can also infect the genital region through oral-genital or genital-genital contact.

Symptomatic HSV-2 typically causes 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.

Neither HSV-1 nor HSV-2 can be cured, and even during times when an infected person has no symptoms, the virus can be found in the body’s nerve cells. Periodically, some people will experience outbreaks 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.

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/AIDS

HIV, or the human immunodeficiency virus,⁷ is the virus that causes AIDS (acquired immunodeficiency syndrome). HIV 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 has progressed to AIDS are very susceptible to opportunistic infections that do not normally make people sick and to certain forms of cancer. AIDS can be prevented by early initiation of antiretroviral therapy in those with HIV infection. Transmission of the virus primarily occurs during unprotected sexual activity and by sharing needles used to inject intravenous drugs, although the virus also can spread from mother to infant during pregnancy, delivery, and breastfeeding.

In 2013, NIH-supported researchers reported that a 2-year-old child who was born with HIV and was treated starting in the first few days of life has had her HIV infection go into remission. This appears to be the first case of functional cure of HIV.

Human Papillomavirus (HPV)

HPV⁸ is the most common STD/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, and mouth.

Although no cure exists for HPV infection once it occurs, 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). A newly available vaccine protects against most (but not all) HPV types that cause cervical cancer. The American Academy of Pediatrics recommends this vaccine for school-aged boys and girls.⁹

Syphilis

Syphilis¹⁰ infections, caused by the bacterium Treponema pallidum, are passed from person to person during vaginal, anal, or oral sex through direct contact with sores, called chancres. Between 2001 and 2009, the Centers for Disease Control and Prevention (CDC) data show that the syphilis rate increased each year. Those people at highest risk for syphilis include men having sex with both men and women and people residing in the south.¹⁰ 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. Beyond being the first sign of a syphilis infection, chancres make a person two to five times more likely to contract an HIV infection. If the person is already infected with HIV, chancres also increase the likelihood that the virus will be passed on to a sexual partner.³ These sores typically resolve on their own, even without treatment.

However, the body does not clear the infection on its own, and, over time, syphilis may involve other organs, including the skin, heart, blood vessels, liver, bones, and joints in secondary syphilis. If the illness is still not treated, tertiary syphilis can develop over a period of years and involve the nerves, eyes, and brain and can potentially cause death.

Expectant mothers harboring the bacterium are at an increased risk of miscarriage and stillbirth, and they can pass the infection on to their fetuses during pregnancy and delivery. Infants that acquire congenital syphilis during pregnancy may suffer from skeletal deformity, difficulty with speech and motor development, seizure, anemia, liver disease, and neurologic problems.

Bacterial Vaginosis

Bacterial vaginosis¹¹ is a common, possibly sexually transmitted, vaginal infection in women of reproductive age. While it is healthy and normal for a vagina to have bacteria, just like the skin, mouth, or gastrointestinal (GI) tract, sometimes changes in the balance of different types of bacteria can cause problems.

Bacterial vaginosis occurs when problematic bacteria that are normally present only in small amounts increase in number, replace normal vaginal lactobacilli bacteria, and upset the usual balance. This situation becomes more likely if a woman douches frequently or has new or multiple sexual partners. The most common sign of a bacterial vaginosis infection is a thin, milky discharge that is often described as having a “fishy” odor. However, some women will have no symptoms at all.

Regardless of symptoms, having bacterial vaginosis increases the risk of getting other STDs/STIs and is also associated with pelvic inflammatory disease (PID), an infection of the female reproductive organs, including the uterus and the fallopian tubes (which carry eggs to the uterus), and postoperative infections. Preterm labor and birth are also possibly more common in women with bacterial vaginosis.

Trichomoniasis

Trichomoniasis12 (pronounced trik-uh-muh- NAHY-uh-sis) infection is caused by the single-celled protozoan parasite Trichomonas vaginalis and is common in young, sexually active women. The parasite 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. Although Trichomonas infections do not always cause symptoms, they can cause frequent, painful, or burning urination in men and women as well as vaginal discharge, genital soreness, redness, or itching in women.

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. As with bacterial STDs/STIs, all sexual partners should be treated at the same time to avoid re-infection.

NICHD-sponsored research has shown that during pregnancy, Trichomonas infection is associated with an increased risk of premature birth and infants with low birth weight. Moreover, infants born to mothers with Trichomonas infection are more than twice as likely as infants born to uninfected women to be stillborn or to die as newborns.¹³

Viral Hepatitis

Viral hepatitis is a serious liver disease that can be caused by several different viruses, which can be transmitted through sexual contact.

• Hepatitis A virus (HAV) causes a short-term or self-limited liver infection that can be quite serious, although it does not result in chronic infection. While there are other ways the virus can be transmitted, HAV can be spread from person to person during sexual activity through oral-rectal contact. Vaccination can prevent HAV infection.¹³

• Hepatitis B virus (HBV) causes a serious liver disease that can result in both immediate illness and lifelong infection leading to permanent liver scarring (cirrhosis), cancer, liver failure, and death. HBV spreads through both heterosexual and homosexual contact as well as through contact with other bodily fluids, such as blood, through shared contaminated needles used for injecting intravenous (IV) drugs, tattooing, and piercing. Pregnant women with HBV can transmit the virus to their infants during delivery. HBV infection is preventable through vaccination.¹

• Hepatitis C virus (HCV) can cause an immediate illness affecting the liver, but it more commonly becomes a silent, chronic infection that leads to liver scarring (cirrhosis), cancer, liver failure, and death. HCV is most commonly transmitted through sharing needles or exposure to infected blood. However, it can spread through sexual contact or from mother to fetus during pregnancy and delivery. There is no vaccine for HCV, and treatments are not always effective.¹⁵[2]

What is the Incidence, Prevalence, and Cost of STIs?

Click on the following link to learn more about the incidence, prevalence, and cost of STIs in the United States:

The Prevalence, Incidence, and Cost of STIs in the US: http://www.ashasexualhealth.org/stdsstis/statistics/

Prevention Techniques for STIs/STDs

Click on the following link to learn how to prevent STIs:

How You Can Prevent STDs:
http://www.ashasexualhealth.org/stdsstis/prevention-tips/

STI Treatment Options:

The following information about the most common STIs is published by the US Department of Health and Human Services and found on the NIH’s website on the page “What are the treatments for sexually transmitted diseases and sexually transmitted infections (STDs/STIs)?”:

STDs/STIs caused by bacteria, yeast, 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. Whatever the infection, and regardless of how quickly the symptoms resolve after beginning treatment, the infected person must take all of the medicine prescribed by the health care provider to ensure that the STD/STI is completely treated.

Although treatments, complications, and outcomes vary among viral STDs/STIs depending on the particular virus (HIV, genital herpes, human papillomavirus, hepatitis, or cytomegalovirus), health care providers can provide treatments to reduce the symptoms and the progression of most of these illnesses. 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. If a woman with HIV becomes pregnant, these medicines also can reduce the chance that her fetus or infant will get the infection.

Being tested and treated for STDs/STIs is especially important for pregnant women because some STDs/STIs may be passed on to their infants during pregnancy or delivery. Testing women for these STDs/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 STD/STI involved.

Developing a Personal Plan for STI Prevention

Plan for Change: Preventing STIs
https://www.cdc.gov/std/prevention/default.htm

Helpful Resources

PSU Student Support Services: https://studentaffairs.psu.edu/student-support-services

PA Department of Health:
https://www.health.pa.gov/topics/HealthStatistics/HealthStatisticsAtoZ/Pages/Sexually-Transmitted-Diseases.aspx

References by Section:

Sexually Transmitted Diseases

• United Nations. Report of the International Conference on Population and Development, Cairo, Egypt, September 5–13, 1994. New York: United Nations; 1995.
• St. Louis ME, Wasserheit JN, Gayle HD, editors. Janus considers the HIV pandemic: Harnessing recent advances to enhance AIDS prevention. Am J Public Health. 1997;87:10-12.

How many people are affected by or at risk for a sexually transmitted disease or sexually transmitted infection (STD/STI)?

• Centers for Disease Control and Prevention. (2012). Sexually transmitted disease surveillance 2011. Atlanta, GA: U.S. Department of Health and Human Services. Retrieved March 19, 2013, from http://www.cdc.gov/std/stats11/Surv2011.pdf (PDF -4.91 MB)

• Centers for Disease Control and Prevention. National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention. Division of HIV/AIDS Prevention. (2012, July). HIV in the United States: At a glance. Retrieved March 19, 2013, from http://www.cdc.gov/hiv/resources/factsheets/PDF/HIV_at_a_glance.pdf (PDF – 512 KB)

What are the Most Common Types of STIs?

• Centers for Disease Control and Prevention. (2012, February 8). Chlamydia-CDC Fact Sheet. Retrieved July 11, 2012, from http://www.cdc.gov/std/chlamydia/STDFact- Chlamydia.htm
• Centers for Disease Control and Prevention. (2012, June 4). Gonorrhea-CDC Fact Sheet. Retrieved July 11, 2012, from http://www.cdc.gov/std/gonorrhea/STDFact- gonorrhea.htm
• Centers for Disease Control and Prevention. (2012, April 11). Basic Information about HIV and AIDS. Retrieved July 11, 2012, from http://www.cdc.gov/hiv/basics/index.html
• Centers for Disease Control and Prevention. (2012, January 31). Genital Herpes-CDC Fact Sheet. Retrieved July 11, 2012, from http://www.cdc.gov/std/herpes/STDFact- Herpes.htm
• Xu, F., Sternberg, M. R., Kottiri, B. J., McQuillan, G. M., Lee, F. K., Nahmias, A. J., Berman, S. M., & Markowitz, L. E. (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

• 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. The Pediatric Infectious Disease Journal, 30, 153-157. PMID 20811312

• Centers for Disease Control and Prevention. National Prevention Information Network. (n.d.). HIV/AIDS Introduction. Retrieved June 3, 2012, from http://www.cdcnpin.org/scripts/hiv/
• Centers for Disease Control and Prevention. (2012, March 22). Sexually transmitted diseases (STDs): Human papilloma virus (HPV). Retrieved June 3, 2012, from http://www.cdc.gov/std/hpv/
• Committee on Infectious Diseases. (2012). HPV vaccine recommendations. Pediatrics, 129, 602-605.
• Centers for Disease Control and Prevention. (2011, November 17). 2010 Sexually Transmitted Diseases Surveillance: Syphilis. Retrieved June 7, 2012, from http://www.cdc.gov/std/stats10/syphilis.htm
• Centers for Disease Control and Prevention. (2010, September 1). Bacterial Vaginosis- CDC Fact Sheet. Retrieved July 11, 2012, from http://www.cdc.gov/std/bv/STDFact- Bacterial-Vaginosis.htm
• Centers for Disease Control and Prevention. (2011, November 30). Trichomoniasis-CDC Fact Sheet. Retrieved July 11, 2012, from http://www.cdc.gov/std/trichomonas/STDFact-Trichomoniasis.htm
• 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.
• Centers for Disease Control and Prevention. (2011, January 28). Sexually transmitted diseases (STDs). Sexually transmitted diseases treatment guidelines, 2010. Vaccine- preventable STDs. Retrieved June 3, 2012, from http://www.cdc.gov/std/treatment/2010/vaccine.htm#a1
• Centers for Disease Control and Prevention. (2011, January 28). Sexually transmitted diseases (STDs). Sexually transmitted diseases treatment guidelines, 2010. Hepatitis C. Retrieved June 3, 2012, from http://www.cdc.gov/std/treatment/2010/hepC.htm

STI Treatment Options

1. Panel on Antiretroviral Guidelines for Adults and Adolescents. (2012). Guidelines for the use of antiretroviral agents in HIV-1-infected adults and adolescents. Washington, DC: Department of Health and Human Services. Retrieved June 3, 2012, from http://aidsinfo.nih.gov/guidelines

NIH – Eunice Kennedy Shriver Institute of Child Health & Human Development

• Copyright and Reuse Text, Images, and Logos

Most text appearing on the NICHD website has been either prepared by employees of the U.S. government as part of their official duties or prepared under contracts for NICHD. In both instances, the text is in the public domain and not subject to copyright. The same is true of most publications available for downloading from this website. You may freely copy that material and credit NICHD with the following notation: “Courtesy: Eunice Kennedy Shriver National Institute of Child Health and Human Development.”

Occasionally, the NICHD site may contain documents or links to documents, such as full- text journal articles, that are copyright-protected. Web users may view and print these documents but should contact the copyright owner for any other uses.

Citing Healthy People 2020

The suggested citation for Healthy People is:

Healthy People 2020 [Internet]. Washington, DC: U.S. Department of Health and Human Services, Office of Disease Prevention and Health Promotion [cited [Date URL was accessed]]. Available from: [Specific URL].