Sexually transmitted disease

(Redirected from STD)
Jump to navigation Jump to search

For patient information click here

Sexually transmitted disease Microchapters

Patient Information



Human Immunodeficiency Virus (HIV)
Human papillomavirus (HPV)
Herpes Simplex Virus (HSV)
Mycoplasma genitalium
Trichomonas vaginalis
Zika Virus
Hepatitis B
Hepatitis C
Bacterial vaginosis

Differential Diagnosis

Risk Factors


Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]}Carla Vorsatz, M.D.[2]; Associate Editor(s)-in-Chief: Tarek Nafee, M.D. [3]

Synonyms and Keywords: Sexually transmissible disease; STD; VD; STI; sexually transmitted infection; venereal disease.


Sexually transmitted diseases (or STDs) are bacterial, viral, fungal, or protozoal infections that are transmitted via sexual contact. Sexual contact may entail non-penetrative contact of the genitalia, performing or receiving oral sex (cunnilingus, anilingus, or fellatio), and insertive or receptive vaginal or anal sexual intercourse. Sexually transmitted infections may have a variety of clinical presentations including dermatological manifestations, generalized symptoms, or urogenital tract symptoms such as discharge and dysuria. Some infectious agents may be transmitted primarily through sexual contact while others may less frequently be transmitted sexually.

The CDC reported updated Surveillance data on sexually transmitted diseases from 2018 in the United States, which included chlamydia, gonorrhea, and syphilis.[1] Complications of STDs depend on the causative pathogen and may range from genital or oral pruritis and discomfort to more serious complications such as pelvic inflammatory disease, primary CNS lymphoma, cervical cancer, as well as cardiac and neurological complications. If left untreated, some STDs may progress to septic shock and death.

Most STDs have well-established risk factors and preventative measures. If followed appropriately, most STD transmissions can be avoided.


Transmission Clinical Presentation Disease Diagnosis Mother to Child Transmission Most Serious Complications
Laboratory Studies Clinical Diagnosis Vertical Transmission Trans-vaginal Transmission
Primarily sexually transmitted Genital Dermatological Manifestation
(e.g., ulcers, chancre, vesicles, warts, balanitis etc.)
HPV Cervical Cancer
''Herpes simplex'' 1 and 2 Moderate to severe pruritis/discomfort, superinfection
Scabies Moderate to severe pruritis/discomfort
Pubic lice Moderate to severe pruritis/discomfort
(in males)
Mild to moderate pruritis/discomfort
Generalized Symptoms
(e.g., constitutional symptoms)
Urogenital infections
(e.g., Vaginitis, Urethritis, Cervicitis, and PID)
Gonorrhea PID
Chlamydia PID
Mycoplasma genitalium unknown unknown PID
''Trichomonas vaginalis'' PID
Less frequently sexually transmitted Generalized Symptoms
(e.g., constitutional symptoms)
Zika Virus Vertical transmission and congenital abnormalities
Hepatitis B Hepatocellular Carcinoma
Hepatitis C Liver cirrhosis, Hepatocellular Carcinoma
Urogenital Infections
(e.g., Vaginitis, Urethritis, Cervicitis, and PID)
''Gardnerella vaginalis'' Moderate to severe discomfort
(in females)
Moderate to severe pruritis/discomfort
Ureaplasma urealyticum Moderate to severe pruritis/discomfort

Differential Diagnosis

Disease Symptoms
Discharge Dysuria Vaginal odor Dyspareunia Genital skin lesion Genital pruritis Fever Lymphadenopathy Other symptoms
Chlamydia Cough, shortness of breath, red eye with discharge (neonate), joint pain
Gonorrhea Sore throat, polyarthralgia, tenosynovitis, rash, eye discharge (neonates)
HIV Fever, lymphadenopathy, rash, fatigue, myalgia, arthritic pain, headache
Herpes simplex Fatigue, myalgia, painful oral ulcers
HPV Weight loss, hoarseness (adults), altered cry, stridor (infants)
Hepatitis B Fever, fatigue, nausea, vomiting, loss of appetite, abdominal pain, dark urine, clay-colored stools, joint pain, yellowish discoloration of the eyes and skin, skin rash, muscle pain
Hepatitis C Fever, fatigue, anorexia, arthralgia, nausea, vomiting
Bacterial vaginosis None
Mycoplasma genitalium None
Zika virus Conjunctivitis, rash, joint pain, myalgia

Risk Factors

Risk factors for acquiring a sexually transmitted disease may vary depending on the disease. However, most sexually transmitted diseases share common risk factors including:

  • Multiple sexual partners
  • Prostitution
  • Illicit drug use
  • Intravenous drug use
  • Unprotected sex
  • Men who have sex with men
  • Residence in highly prevalent areas
  • Underlying HIV infection as a risk for other STDs
  • Presence of other STDs
  • Previous history of STDs
  • Low socioeconomic status
  • Health care professionals who are predisposed to occupational risk with infected patients


The most effective way to prevent sexual transmission of STIs is to avoid contact of body parts or fluids which can lead to transfer. Abstinence is one method of avoiding contact. Ideally, both partners should get tested for STIs before initiating sexual contact, or if a partner engaged in contact with someone else.


Vaccines are available that protect against some viral STDs, such as Hepatitis B, Herpes simplex (Herpevac and ImmunoVex, both in clinical trials not yet approved by the FDA), and some types of HPV. Vaccination before initiation of sexual contact is advised to assure maximal protection.

Barrier Protection

Condoms only provide protection when used properly as a barrier and 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 vaginaand 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.

Condoms are designed, tested, and manufactured to never fail if used properly. There has not been any documented case of an HIV transmission due to an improperly manufactured condom. However, there have been cases of condom recall, as in a case in South Africa.

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 ejaculate. 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 or polyurethane, as they don't protect against HIV.
  • Avoiding the use of oil-based lubricants (or anything with oil in it) with latex condoms, as oil can cause thinning and perforation of the material.

Not following the five guidelines above perpetuates the common misconception that condoms are not appropriately designed or tested.

In order to best protect oneself and the partner from STIs, a condom used by an infected individual and its contents should be assumed to be still infectious. Therefore the used condom must be properly disposed. A new condom should be used for each act of intercourse, as multiple usages increase the chance of breakage, defeating the primary purpose as a barrier and increases the risk of disease transmission.


  1. CDC Sexually Transmitted Disease Surveillance 2018 STDs in the United States. The Centers for Disease Control and Prevention. Accessed on January 25, 2020.

Template:WH Template:WS